BTCC Honda Civic Typr R nary lifts a rear wheel - why?
12-14-2003, 12:48 PM
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BTCC Honda Civic Typr R nary lifts a rear wheel - why?
After viewing several of the BTCC races recently airing on the Speed Channel, as well as some of the European races, I have been noticing that virtually all front drive cars in those series hardly lift a rear wheel in any corner. I observed particularly the race winning Honda CTR of Matt Neal, and on every corner, in the absence of launching over curbs, all four wheels are almost always on the ground. No pissing dog effect. What do they know about making the most of the tractive wheels while keeping all four on the ground?
The recent Racecar Engineering article by Mark Ortiz on front wheel drive cars might have some hints. I can be found in this link:
http://www.auto-ware.com/ubbth...art=1
He says:
"I have had a number of inquiries lately from people racing front-wheel-drive cars, asking about literature or information sources about setting up front-drive cars. It appears there is a distinct lack of literature currently in print on this subject, at least beyond manuals dealing with particular cars, and brief passages in general chassis books." He is right there, virtually zero in the books I know of.
A first quote from Mr. Ortiz:
"I mentioned the tendency for a car to try to leave the desired path heavy-end-first. We have two principal tools we can use to control this tendency: use bigger and/or stickier tires at the heavy end of the car"
A second quote:
"With front drive, this load transfer works against us. Consequently, we are faced with a dilemma: maximize front-heaviness so we can put power down, or minimize front-heaviness so we can corner"
A third quote:
"Regarding suspension setup, we are forced to work around the fact that the front wheels limit the car. If the car were not nose-heavy, it might make sense to give the front and rear suspension systems similar roll resistance, and try to work all four tires. A front-drive car done this way (if it were possible, which would only occur if we had lots of ballast to work with) would have very poor forward bite. Since a front-drive car is necessarily nose-heavy, it must be set up to work the front tires as evenly as possible. That means it must corner with the inside rear tire very lightly loaded or airborne. We trade away lateral grip at the rear to gain more at the front, where we need it."
And then he goes on to say:
"We also gain drive traction on the inside front wheel. This is important in a front-drive car, because we cannot use limited-slip differentials that lock too firmly or abruptly, unless the driver has great tolerance for steering fight.
It is important to note that once the inside rear wheel is airborne, the rear suspension has contributed all the anti-roll moment it can, and any further roll resistance has to come from the front. Up to the point of rear wheel lift, rear load transfer builds faster than front load transfer. Beyond that point, rear load transfer is 100%, and front load transfer builds rapidly. So does roll angle. So does understeer.
As a general rule, to get a car that has good consistency as grip varies, we want the inside rear wheel to lift just a little in steady-state cornering, when grip is good. If it lifts more than that, we are likely to have a relatively loose car when grip is poor and a much tighter car when grip is good."
So is this why the BTCC Honda CTR appears to never lift a wheel. They have it so finely tuned that that inside rear never actually comes off the ground, it just kisses it. In the SCCA run-offs being aired, the FWD cars are regularly running on three wheels in many corners, locking the inside rear under braking and generally much more off the ground. Do those BTCC guys know something we don't?
P.S. There was a post a while back where people were lamenting the lack of Honda support for racing. Seems that factory CTR team offered its drivers a brand new NSX each if they finished 1-2-3. They almost did it: 1-2-4. Now that sure beats free tires.
The recent Racecar Engineering article by Mark Ortiz on front wheel drive cars might have some hints. I can be found in this link:
http://www.auto-ware.com/ubbth...art=1
He says:
"I have had a number of inquiries lately from people racing front-wheel-drive cars, asking about literature or information sources about setting up front-drive cars. It appears there is a distinct lack of literature currently in print on this subject, at least beyond manuals dealing with particular cars, and brief passages in general chassis books." He is right there, virtually zero in the books I know of.
A first quote from Mr. Ortiz:
"I mentioned the tendency for a car to try to leave the desired path heavy-end-first. We have two principal tools we can use to control this tendency: use bigger and/or stickier tires at the heavy end of the car"
A second quote:
"With front drive, this load transfer works against us. Consequently, we are faced with a dilemma: maximize front-heaviness so we can put power down, or minimize front-heaviness so we can corner"
A third quote:
"Regarding suspension setup, we are forced to work around the fact that the front wheels limit the car. If the car were not nose-heavy, it might make sense to give the front and rear suspension systems similar roll resistance, and try to work all four tires. A front-drive car done this way (if it were possible, which would only occur if we had lots of ballast to work with) would have very poor forward bite. Since a front-drive car is necessarily nose-heavy, it must be set up to work the front tires as evenly as possible. That means it must corner with the inside rear tire very lightly loaded or airborne. We trade away lateral grip at the rear to gain more at the front, where we need it."
And then he goes on to say:
"We also gain drive traction on the inside front wheel. This is important in a front-drive car, because we cannot use limited-slip differentials that lock too firmly or abruptly, unless the driver has great tolerance for steering fight.
It is important to note that once the inside rear wheel is airborne, the rear suspension has contributed all the anti-roll moment it can, and any further roll resistance has to come from the front. Up to the point of rear wheel lift, rear load transfer builds faster than front load transfer. Beyond that point, rear load transfer is 100%, and front load transfer builds rapidly. So does roll angle. So does understeer.
As a general rule, to get a car that has good consistency as grip varies, we want the inside rear wheel to lift just a little in steady-state cornering, when grip is good. If it lifts more than that, we are likely to have a relatively loose car when grip is poor and a much tighter car when grip is good."
So is this why the BTCC Honda CTR appears to never lift a wheel. They have it so finely tuned that that inside rear never actually comes off the ground, it just kisses it. In the SCCA run-offs being aired, the FWD cars are regularly running on three wheels in many corners, locking the inside rear under braking and generally much more off the ground. Do those BTCC guys know something we don't?
P.S. There was a post a while back where people were lamenting the lack of Honda support for racing. Seems that factory CTR team offered its drivers a brand new NSX each if they finished 1-2-3. They almost did it: 1-2-4. Now that sure beats free tires.
12-14-2003, 01:27 PM
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (descartesfool)
I cant say for sure, but they use a custom valved Penske setup, and they may be trying out the "new school" suspension theory that the reps from KW suspensions almost sold me on:
The damper's slow-rate-bump (roll-resistance) controls the roll, while the spring (with a lower rate) controls the high-rate-bump (rumble).
It seems counter-intuitive since it essentially does keep the car from lifting, but they also are radically slammed and cambered, so maybe that has something to do with it's cornering ability without lift. They must have some really smooth tracks
!
The damper's slow-rate-bump (roll-resistance) controls the roll, while the spring (with a lower rate) controls the high-rate-bump (rumble).
It seems counter-intuitive since it essentially does keep the car from lifting, but they also are radically slammed and cambered, so maybe that has something to do with it's cornering ability without lift. They must have some really smooth tracks
!
12-14-2003, 02:05 PM
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (descartesfool)
It just seems like their emphasis is on generating more front grip, rather than reducing rear grip to allow for rotation as a means to combat understeer.
12-14-2003, 02:17 PM
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (hatch2k)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hatch2k »</TD></TR><TR><TD CLASS="quote">I cant say for sure, but they use a custom valved Penske setup, and they may be trying out the "new school" suspension theory that the reps from KW suspensions almost sold me on:
The damper's slow-rate-bump (roll-resistance) controls the roll, while the spring (with a lower rate) controls the high-rate-bump (rumble).
It seems counter-intuitive since it essentially does keep the car from lifting, but they also are radically slammed and cambered, so maybe that has something to do with it's cornering ability without lift. They must have some really smooth tracks !</TD></TR></TABLE>
THe Honda BTCC team isn't using Penske for their suspension.
The damper's slow-rate-bump (roll-resistance) controls the roll, while the spring (with a lower rate) controls the high-rate-bump (rumble).
It seems counter-intuitive since it essentially does keep the car from lifting, but they also are radically slammed and cambered, so maybe that has something to do with it's cornering ability without lift. They must have some really smooth tracks
!</TD></TR></TABLE>THe Honda BTCC team isn't using Penske for their suspension.
12-14-2003, 02:41 PM
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (descartesfool)
The King and RTR RSX's don't lift much if any either. That despite incredible rear spring rates (yes, and wheel rates) and relatively soft front rates.
It all comes down to F/R weight bias, the F/R roll stiffness, and the amount of lateral grip.
Maybe next year with more grip on RA1's you'll see a little air under the RSX's inside rear at corner entry.
I'd be skeptical of anyone offering cyclically dated damper theories without having their own hardware on the specific cars under discussion. I wasn't aware that supporting the car with compression damping had come around again.
Scott, who suggests that if the front roll stiffness is high enough you needn't expect the inside rear to lift off...it's probably nothing more than that simple.
It all comes down to F/R weight bias, the F/R roll stiffness, and the amount of lateral grip.
Maybe next year with more grip on RA1's you'll see a little air under the RSX's inside rear at corner entry.
I'd be skeptical of anyone offering cyclically dated damper theories without having their own hardware on the specific cars under discussion. I wasn't aware that supporting the car with compression damping had come around again.
Scott, who suggests that if the front roll stiffness is high enough you needn't expect the inside rear to lift off...it's probably nothing more than that simple.
12-14-2003, 04:16 PM
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (RR98ITR)
RA1' maybe, but the BTCC cars run on slicks, so grip is very high, and they likely have more downforce with their wings and lips (via aero R&D). In the past, circa 1997 and up, RTR's ITR's definitely lifted their rear leg on many turns. While I am well aware that it depends on front % weight and relative roll stiffness F/R, the fact that it used to be thought it was faster around the track with the rear wheel lifting (as in ITR winning multiple championships with rear wheel lifting) but that today it might be thought it is the slow way around is of some interest.
Is it because of the A-arm vs. McPherson struts on these new Honda's that the roll stiffness balance % has been put closer to the front weight bias % causing less rear wheel lift than before, or is some other setup method being used that would apply to any FWD suspension?. Is it due to a change in the resistance due to roll centre height (McPherson vs. SLA), or a change in the % of roll resistance coming from roll bars vs. springs, or damper settings.
I have also noticed that the King and RTR RSX's don't lift much either. But this is fairly new. Watching cars go around turn 2 in this year's run-offs had lots of rear wheel lift, as in the older RTR ITR's. Can all these cars be made to go faster with a new setup keeping the wheels all on the ground. Obviously total lateral grip is going to be larger, but exit speed may be compromised due to overworking the fronts. If the rear tire is not lifting, rear grip is higher and car won't rotate as easily, making it more difficult to put the power down on exit. My main question is can we find a setup that gives good exit speed while leaving all four corners on the ground?
Is it because of the A-arm vs. McPherson struts on these new Honda's that the roll stiffness balance % has been put closer to the front weight bias % causing less rear wheel lift than before, or is some other setup method being used that would apply to any FWD suspension?. Is it due to a change in the resistance due to roll centre height (McPherson vs. SLA), or a change in the % of roll resistance coming from roll bars vs. springs, or damper settings.
I have also noticed that the King and RTR RSX's don't lift much either. But this is fairly new. Watching cars go around turn 2 in this year's run-offs had lots of rear wheel lift, as in the older RTR ITR's. Can all these cars be made to go faster with a new setup keeping the wheels all on the ground. Obviously total lateral grip is going to be larger, but exit speed may be compromised due to overworking the fronts. If the rear tire is not lifting, rear grip is higher and car won't rotate as easily, making it more difficult to put the power down on exit. My main question is can we find a setup that gives good exit speed while leaving all four corners on the ground?
12-14-2003, 05:34 PM
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (descartesfool)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by descartesfool »</TD></TR><TR><TD CLASS="quote">... it used to be thought it was faster around the track with the rear wheel lifting (as in ITR winning multiple championships with rear wheel lifting) but that today it might be thought it is the slow way around is of some interest...
My main question is can we find a setup that gives good exit speed while leaving all four corners on the ground?</TD></TR></TABLE>
"It used to be thought" only in the simplest sense.
In my "epic" work I wrote about how as you had less front weight bias, lower cg, and more lateral grip you'd have to take the front roll stiffness higher.
Then stop to consider the differences in these chassis. The ITR has a below ground front roll center and depends on springs and bars for it's roll stiffness.
The RSX having a strut front end has and needs a significantly higher front roll center else it would suffer from a much worse camber curve. I can't recall if the front bar is of a more efficient design on the RSX. There is nothing else about the strut front end that I can imagine bearing on this topic.
Inside rear lift in and of itself doesn't seem to be a big deal as far as the drivers control is concerned. Nobody reports sensing any disruption in that event. To seek explicitly to either lift or not lift seems to me to be relatively unimportant on that basis.
I've asked far and wide for opinions as to the importance of lateral roll center migration and the large instantaneous lateral movements associated with lifting - and I can't find anyone with an unambiguous argument based on focused testing results. At least I can't find anyone who will talk about it.
To discuss this subject further we really need to know the following:
Weight distribution on typical BTCC FWD cars?
RSX motion ratios (including front sway bar motion ratio)?
RSX roll center locations?
WC RSX weight distribution?
ETC?
Scott, who thinks that if magic shocks on a well setup car delivers enough front grip to the point that you don't need so much roll stiffness bias as to cause lift, then good for you...this is after all science, not religion...
My main question is can we find a setup that gives good exit speed while leaving all four corners on the ground?</TD></TR></TABLE>
"It used to be thought" only in the simplest sense.
In my "epic" work I wrote about how as you had less front weight bias, lower cg, and more lateral grip you'd have to take the front roll stiffness higher.
Then stop to consider the differences in these chassis. The ITR has a below ground front roll center and depends on springs and bars for it's roll stiffness.
The RSX having a strut front end has and needs a significantly higher front roll center else it would suffer from a much worse camber curve. I can't recall if the front bar is of a more efficient design on the RSX. There is nothing else about the strut front end that I can imagine bearing on this topic.
Inside rear lift in and of itself doesn't seem to be a big deal as far as the drivers control is concerned. Nobody reports sensing any disruption in that event. To seek explicitly to either lift or not lift seems to me to be relatively unimportant on that basis.
I've asked far and wide for opinions as to the importance of lateral roll center migration and the large instantaneous lateral movements associated with lifting - and I can't find anyone with an unambiguous argument based on focused testing results. At least I can't find anyone who will talk about it.
To discuss this subject further we really need to know the following:
Weight distribution on typical BTCC FWD cars?
RSX motion ratios (including front sway bar motion ratio)?
RSX roll center locations?
WC RSX weight distribution?
ETC?
Scott, who thinks that if magic shocks on a well setup car delivers enough front grip to the point that you don't need so much roll stiffness bias as to cause lift, then good for you...this is after all science, not religion...
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12-14-2003, 06:22 PM
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Ok, I haven't near the experience of most of you guys....but couldn't it just be the fact that these cars have more droop travel than most of you are used to seeing?
Jesse, looking for an easy answer before delving into it more seriously. Ok...back to studying for my dynamics final
Jesse, looking for an easy answer before delving into it more seriously. Ok...back to studying for my dynamics final
12-14-2003, 06:32 PM
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (RR98ITR)
Knowone really went into chassis design dont you think that the ep3 chassis is much stiffer than the dc2 ? I know that everyone will say that after all bars and roll cage it would plenty stiff, but dont you think that the frame has anything to do with it or am i off?
Edit i meant dc2 not dc5 sorry
Modified by combustion at 8:42 AM 12/15/2003
Edit i meant dc2 not dc5 sorry
Modified by combustion at 8:42 AM 12/15/2003
12-14-2003, 06:33 PM
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (RR98ITR)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Littleton »</TD></TR><TR><TD CLASS="quote">
THe Honda BTCC team isn't using Penske for their suspension.</TD></TR></TABLE>
Then they need to update their BTCC team stats page with the correct info: http://www.btccpages.com/teams/2003/civict.php
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR »</TD></TR><TR><TD CLASS="quote">
I'd be skeptical of anyone offering cyclically dated damper theories without having their own hardware on the specific cars under discussion. I wasn't aware that supporting the car with compression damping had come around again.
</TD></TR></TABLE>
In KW's defense, they do have an extensive amount of experience with suspension on the EP3, having developed supplied all the suspension for the EP3-only racing series in Portugal, as well as the two EP3-R's in the ETCC.
BUT, I was still skeptical about the theroy,too, and I went with JIC's instead
THe Honda BTCC team isn't using Penske for their suspension.</TD></TR></TABLE>
Then they need to update their BTCC team stats page with the correct info: http://www.btccpages.com/teams/2003/civict.php
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR »</TD></TR><TR><TD CLASS="quote">
I'd be skeptical of anyone offering cyclically dated damper theories without having their own hardware on the specific cars under discussion. I wasn't aware that supporting the car with compression damping had come around again.
</TD></TR></TABLE>
In KW's defense, they do have an extensive amount of experience with suspension on the EP3, having developed supplied all the suspension for the EP3-only racing series in Portugal, as well as the two EP3-R's in the ETCC.
BUT, I was still skeptical about the theroy,too, and I went with JIC's instead
12-14-2003, 06:54 PM
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (combustion)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by combustion »</TD></TR><TR><TD CLASS="quote">Knowone really went into chassis design dont you think that the ep3 chassis is much stiffer than the dc5 would you not think so. I know that everyone will say that after all bars and roll cage it would plenty stiff but dont you think that the base has anything to do with it or am i off?</TD></TR></TABLE>
What the hell are you talking about?
What the hell are you talking about?
12-14-2003, 06:57 PM
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Re: (PseudoRealityX)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PseudoRealityX »</TD></TR><TR><TD CLASS="quote">....but couldn't it just be the fact that these cars have more droop travel than most of you are used to seeing?
</TD></TR></TABLE>
Nope - that's not it.
"Droop travel" as you're using it is somewhat dependent on static deflection. How much do you think one of these cars with 3000lb rear spring rates has?
Scott, who will have to eventually indulge his curiousity about these new chassis'...you KNOW they've got to have plenty of passive rear steer built in...
</TD></TR></TABLE>
Nope - that's not it.
"Droop travel" as you're using it is somewhat dependent on static deflection. How much do you think one of these cars with 3000lb rear spring rates has?
Scott, who will have to eventually indulge his curiousity about these new chassis'...you KNOW they've got to have plenty of passive rear steer built in...
12-14-2003, 07:23 PM
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Re: (RR98ITR)
Consider that the RSX is a strut front end with limited camber gain versus the control arm setup of older Hondas. A strut front end will often gain cornering ability with a stiffer anti-roll bar due to keeping the car from rolling and changing the camber. This can be made less important by adding more static camber, but that reduces braking and straightline acceleration traction.
What if they are running really stiff rear springs but a relatively small rear bar? It would give the roll stiffness but would not effect the opposite rear wheel as much as a big bar would.
When the touring cars ran in the US a few years ago, they had multi-spring setups. They may in fact have quite a bit of droop travel built in. They seemed to have enough travel to almost drag the rocker panels on the ground. Besides, they probably have more money in their shocks than most of us make in a year, they should work really well.
What if they are running really stiff rear springs but a relatively small rear bar? It would give the roll stiffness but would not effect the opposite rear wheel as much as a big bar would.
When the touring cars ran in the US a few years ago, they had multi-spring setups. They may in fact have quite a bit of droop travel built in. They seemed to have enough travel to almost drag the rocker panels on the ground. Besides, they probably have more money in their shocks than most of us make in a year, they should work really well.
12-14-2003, 07:34 PM
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Re: (RR98ITR)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR »</TD></TR><TR><TD CLASS="quote">
Nope - that's not it.
"Droop travel" as you're using it is somewhat dependent on static deflection. How much do you think one of these cars with 3000lb rear spring rates has?
Scott, who will have to eventually indulge his curiousity about these new chassis'...you KNOW they've got to have plenty of passive rear steer built in...</TD></TR></TABLE>
I don't know the ins and outs of helper springs, but isn't this one of the purposes? The helper spring becomes basically solid upon any real force, even in normal ride height conditions. I could be wrong...but I'm asking, because i'm interested as there's not much talk EVER on them from what I've seen.
Nope - that's not it.
"Droop travel" as you're using it is somewhat dependent on static deflection. How much do you think one of these cars with 3000lb rear spring rates has?
Scott, who will have to eventually indulge his curiousity about these new chassis'...you KNOW they've got to have plenty of passive rear steer built in...</TD></TR></TABLE>
I don't know the ins and outs of helper springs, but isn't this one of the purposes? The helper spring becomes basically solid upon any real force, even in normal ride height conditions. I could be wrong...but I'm asking, because i'm interested as there's not much talk EVER on them from what I've seen.
12-14-2003, 10:51 PM
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (hatch2k)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hatch2k »</TD></TR><TR><TD CLASS="quote">
Then they need to update their BTCC team stats page with the correct info: http://www.btccpages.com/teams/2003/civict.php
In KW's defense, they do have an extensive amount of experience with suspension on the EP3, having developed supplied all the suspension for the EP3-only racing series in Portugal, as well as the two EP3-R's in the ETCC.
BUT, I was still skeptical about the theroy,too, and I went with JIC's instead </TD></TR></TABLE>
My team has a contract with a suspension company that has told us otherwise. Maybe i've been misinformed. I'll certainly follow up on this issue and get back to you.
Then they need to update their BTCC team stats page with the correct info: http://www.btccpages.com/teams/2003/civict.php
In KW's defense, they do have an extensive amount of experience with suspension on the EP3, having developed supplied all the suspension for the EP3-only racing series in Portugal, as well as the two EP3-R's in the ETCC.
BUT, I was still skeptical about the theroy,too, and I went with JIC's instead
</TD></TR></TABLE>My team has a contract with a suspension company that has told us otherwise. Maybe i've been misinformed. I'll certainly follow up on this issue and get back to you.
12-14-2003, 11:13 PM
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Re: (sjracer)
I would think they may be using a smaller sway bar then most of us think to use and increase the spring rates to compensate for it. The larger sway bar used the more it takes away from what independent suspension was designed to do. Any one else agree with the theory?
12-15-2003, 04:41 AM
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (.RJ)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ »</TD></TR><TR><TD CLASS="quote">
What the hell are you talking about?</TD></TR></TABLE>
I was talking about the chassis does'nt the dc2 chassis flex more than the the ep3 and dc5?
What the hell are you talking about?</TD></TR></TABLE>
I was talking about the chassis does'nt the dc2 chassis flex more than the the ep3 and dc5?
12-15-2003, 04:48 AM
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Re: (DMF)
I had the opportunity to tech a couple of BTCC cars.(2000 Williams) These things are not nearly as nose heavy as our street based bretheren. When you open the front hood, it is very apparent to what lengths they go to to move the weight bias to the rear. When you opened the hood, all you could see of the engine was the top of the valve cover and the intake stacks, the engine was at a ~60deg angle and shoved under the passenger floor. I would imagine that these cars run a hell of a lot closer to a 50/50 weight distribution than most of us can only dream of. That will go a LONG way to keeping the car flat in the corner.
12-15-2003, 07:15 AM
#20
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Re: (MightyMouseTech)
I believe that the touring cars of 2000 were much further from "stock" vehicles than those of today after a massive rules change to bring expenses down, so I don't know if they can still locate the engine wherever they want to now.
12-15-2003, 07:30 AM
#21
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Re: (Civic44)
High grip
Very high spring rates
Very light cars (less weight transfer)
Low roll centers
Rear wings
They do lift, just not very much.
My Civic lifts the inside rear far less than my Integra did. The Integra was tossing much more, and higher, weight around. This (roll center) is why the taller VW GTIs lift the rears wayyyy off the ground. Those cars are cornering best when they look like they're about to flip over.
In the end, all the FWD cars are lifting the inside rears. Its just a matter of some more than others. The reasons are many and varied from car to car and class to class.
Very high spring rates
Very light cars (less weight transfer)
Low roll centers
Rear wings
They do lift, just not very much.
My Civic lifts the inside rear far less than my Integra did. The Integra was tossing much more, and higher, weight around. This (roll center) is why the taller VW GTIs lift the rears wayyyy off the ground. Those cars are cornering best when they look like they're about to flip over.
In the end, all the FWD cars are lifting the inside rears. Its just a matter of some more than others. The reasons are many and varied from car to car and class to class.
12-15-2003, 08:14 AM
#22
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Re: BTCC Honda Civic Typr R nary lifts a rear wheel - why? (combustion)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by combustion »</TD></TR><TR><TD CLASS="quote">I was talking about the chassis does'nt the dc2 chassis flex more than the the ep3 and dc5?</TD></TR></TABLE>
You gotta engage your brain before you type man
You gotta engage your brain before you type man
12-15-2003, 11:09 AM
#24
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Re: (JMU R1)
"any suspension will work if you don't let it"
the ep3 and dc5 both have a horrible front camber curve (compared to the dc2)and more bump steer. it's easy to see that you would have to minimize roll to maximize the contact patch of the outside front. spice with enough rear roll stiffness to get all the weight off the inside rear, serve warm.
the comment i found interesting....
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mark Ortiz »</TD></TR><TR><TD CLASS="quote">It is important to note that once the inside rear wheel is airborne, the rear suspension has contributed all the anti-roll moment it can, and any further roll resistance has to come from the front. Up to the point of rear wheel lift, rear load transfer builds faster than front load transfer. Beyond that point, rear load transfer is 100%, and front load transfer builds rapidly. So does roll angle. So does understeer.
As a general rule, to get a car that has good consistency as grip varies, we want the inside rear wheel to lift just a little in steady-state cornering, when grip is good. If it lifts more than that, we are likely to have a relatively loose car when grip is poor and a much tighter car when grip is good.</TD></TR></TABLE>
nate-is tired of a car that is a perpetual state of spin whenever it rains...
the ep3 and dc5 both have a horrible front camber curve (compared to the dc2)and more bump steer. it's easy to see that you would have to minimize roll to maximize the contact patch of the outside front. spice with enough rear roll stiffness to get all the weight off the inside rear, serve warm.
the comment i found interesting....
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mark Ortiz »</TD></TR><TR><TD CLASS="quote">It is important to note that once the inside rear wheel is airborne, the rear suspension has contributed all the anti-roll moment it can, and any further roll resistance has to come from the front. Up to the point of rear wheel lift, rear load transfer builds faster than front load transfer. Beyond that point, rear load transfer is 100%, and front load transfer builds rapidly. So does roll angle. So does understeer.
As a general rule, to get a car that has good consistency as grip varies, we want the inside rear wheel to lift just a little in steady-state cornering, when grip is good. If it lifts more than that, we are likely to have a relatively loose car when grip is poor and a much tighter car when grip is good.</TD></TR></TABLE>
nate-is tired of a car that is a perpetual state of spin whenever it rains...
12-15-2003, 11:18 AM
#25
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Re: (Civic44)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Civic44 »</TD></TR><TR><TD CLASS="quote">I believe that the touring cars of 2000 were much further from "stock" vehicles than those of today after a massive rules change to bring expenses down, so I don't know if they can still locate the engine wherever they want to now.</TD></TR></TABLE>
Yeah the "super" tourers were quite amazing. Did you ever see Ken Mcrae's Williams Laguna? He ran in the Canada GT Challenge cup, I spent about 2 hours looking at the suspension of that car at Shannonville, it is VERY advanced. The rear especially, I remember, it was based what looked like a twist beam rear axle, but it was Heim jointed in the middle, the rear shocks were nealy laying flat too, I found that quite odd. I talked to Ken for quite a long time, he had no idea how they came to that design, but hey, its Williams..
It is an amzing car.
Yeah the "super" tourers were quite amazing. Did you ever see Ken Mcrae's Williams Laguna? He ran in the Canada GT Challenge cup, I spent about 2 hours looking at the suspension of that car at Shannonville, it is VERY advanced. The rear especially, I remember, it was based what looked like a twist beam rear axle, but it was Heim jointed in the middle, the rear shocks were nealy laying flat too, I found that quite odd. I talked to Ken for quite a long time, he had no idea how they came to that design, but hey, its Williams..
It is an amzing car.