Not a honda, but our track car (SRF #76)......

This is our first year and we're still working out all the bugs and trying to learn suspension geomtry as we go.

we're having a problem with the the rear end washing out at mid corner all the way to corner exit. again, the car is RWD with a rear engine, corner weighted 50/50 left to right and 60/40 rear to front. Camber/caster/toe have all been set. any idea on what we should be looking for to help combat this?

thanks!

 

I'm not sure how helpful this would be, but have you talked to any of the Porsche guys? Sounds like their setups would be similar to yours, as the engine layout and weight distribution is similar.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sscguy &raquo;</TD></TR><TR><TD CLASS="quote">I'm not sure how helpful this would be, but have you talked to any of the Porsche guys? Sounds like their setups would be similar to yours, as the engine layout and weight distribution is similar.</TD></TR></TABLE>

not even close. an SRF is a true race car, not a mac strut tin top.

what is your rear alignment like? toe, camber? is the problem most evident off slow corners or fast ones? how is the cars balance on entry? i assume you have a cockpit adjustable swaybar, does softening the swaybar help any?

btw, i'm driving an 85 Reynard FF in Solo2.

ps. how old are your tires?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo-x &raquo;</TD></TR><TR><TD CLASS="quote">

not even close. an SRF is a true race car, not a mac strut tin top.

what is your rear alignment like? toe, camber? is the problem most evident off slow corners or fast ones? how is the cars balance on entry? i assume you have a cockpit adjustable swaybar, does softening the swaybar help any?

btw, i'm driving an 85 Reynard FF in Solo2.

ps. how old are your tires?</TD></TR></TABLE>


Alignment reads as follows: 3/8 toe out front, 3/16 toe in rear.

Camber: 3.4* front
3* rear (we worry pushing rear camber any further in the rear due to CV angles)

Mostly at hard 4th gear + corners (90-110mph) Entry feels fine, bites and makes the intitial turn in great, its when power comes on at mid corner she starts to step out. sway bar was adjusted to full soft to compensate.

Tires are getting worn, this is the third weekend on them, but from all reports in the SRF Community they are good for 5 weekends. its a new spec goodyear eagle bias tire.

 

are you sure you want that much toe?
I had heard from other SRF guys that they run 0 toe all around, (like us in SM).
Not just for handling, but to minimize tire drag

 

we're still playing around with it.....

*BUT* this is the same set up that a certain National SRF driver used two weeks ago and won at the Glen......


(were you at the July Sprints at the Glen last weekend? quite a large SM crowd as usual)

 

sounds like a lot of camber for a bias ply on both ends, but if it's working and your getting good lateral g's from it then it shouldn't be the cause of your problem. if i had to guess, i'd say you're getting an aero loose condition. have you tried adding more rake?

 

hehe...our thought process's are on the same page!

two weeks ago at the Glen Nationals we had 1/4 postive rake. After some serious consulting and "investigating" we found out around the paddock that most guys were running a Zero rake or even a 1/4 NEGATIVE rake!

we went to 1/4 negative rake, but after we got done corner-weighting we ended up with just about a perfectly flat rake. we were able to put down times 2 seconds fater than our best time last week.

Postive rake we were consistently running 2.19-2.20s

Yesterday we were running low 2.18s and even a few 2.17s. Yet we still had problems with oversteer....we're reviewing the tapes and wondering if perhaps the the driver was over-driving the car...we'll see.

the discussion thus far has been great though!

 

SEE SIG

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Team Bukkake Sucks!!! &raquo;</TD></TR><TR><TD CLASS="quote">SEE SIG</TD></TR></TABLE>

ah, for life to be so simple that you can regurgitate setup manuals and claim them as your own....

for shocks to solve this problem, the problem would need to be exhibited in all types of corners. it would also be more pronounced at low speed (particularly a rear shock change) since you'll have more rearward load transfer due to acceleration.

i originally assumed the driver induced influences had been examined and ruled out.

did the car get tighter in slow stuff and looser in high speed stuff when you went to zero rake? positive rake should increase overall downforce and move the aero dynamic balance towards understeer. if you don't change bar and spring rates though, the car will get looser in low speed stuff. the opposite will happen if you go towards zero or more negative rake. the car will get tighter in slow stuff but the aero package will move the car towards oversteer at higher speeds.

how do those lap times compare to the track record and the fastest guy of the weekend? using lap times to figure out if a change was an improvement or not is dicey at best. did the driver just have a really good weekend/race/lap? was the track especially quick? a lot of good drafts? perhaps the driver was just that much more comfortable in the car? i'm not saying it's a bad thing, if lap times dropped after the change, the change was good. i wouldn't assume the car was faster overall though, just that the driver/car package was faster for the conditions of the day.

nate - has made improvements over 2 seconds per run in solo2 before without making any changes to the car