just having a friendly debate with some friends over trap speed comparison between FWD and RWD.

i am thinking it is somewhat relative but not exactly, and heres my side, please comment and fix me if i am wrong.


RWD's seem to have a slightly lower trap speed/ET ratio because they seem to hook up better, for example (not correct #s) if a RWD would run a 10.00@135, when you look at FWD it would seem more like 10.00@140


does this seem correct due to weight transfer, axle location, and traction.

 

more or less it boils down to the RWD getting the much better 60ft time, which affects the entire run.

 

as i was thinking so far, if you net a quicker 60ft time and quicker 1/8th and quarter shouldnt your speeds be slightly slower than a car who had to build more speed after the 1/8th?


thanks

 

yeah i noticed that too, u got fwd cars running low 10s at 148 ect ect, and rwd cars running nines with the same MPH,

60ft and weight transfer must be the answer

 

Isn't this also true for allmotor fwd cars vs. turbo fwd cars? The allmotor car will have the same ET with a lower MPH. Again the allmotor car has the better 60'.

 

also might have to do with most rwd cars having V8's and a flatter HP and Torque curve instead of it being "peaky" like in a honda.

 

60 ft = ET

Horsepower influences mph

I dunno anything though.

 

how far off trap speed would be if you have let say .5 sec diff in 60 ft. time?

 

i have noticed that the lighter all motor cars seem to be dialed in as far as ET vs MPH, thier mphs are sooo dead on when it came to ET, it was almost freakish, but on the other hand the turbo cars were like 10mph faster


what im trying to get at is i hear some people say "well thats a 9 second mph" my question is IN WHAT??? what car are you referring to is xxx.XX mph is a 9 second time slip??

anyone understand what i mean?

 

alot depends on the weight of the vehicle as well.......


we cant do **** out of the hole, but got a killer top end...


then we got the v8's which are great out of the hole,(rwd comes into play) but the weight and seemingly "lack of top end power" kill the trap speed. but the e.t. is there.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18prl &raquo;</TD></TR><TR><TD CLASS="quote">how far off trap speed would be if you have let say .5 sec diff in 60 ft. time?</TD></TR></TABLE>


from what i understand... .2 less/more in the 60 ft. will = 2 less/more tenths on top end.

 

its all in the 60ft

 

A perfect example of this would be the MOPAR Neon of Shaun Carlson. In Pomona lastNov. he was putting down 7.80's with like a 140-150 trap. This indicates that he probably isnt making too much power, but is getting maximum traction. Another influence is the weight of the car. When you take weight/traction/HP and figure out the ratios (whatever those may be) you determine est. ET.
I THINK!

Gary I.

 

Actually in the 7.80 pass.... the throttle cable let go at 155MPH, right at 1/8 mile..... that pass would easily turn 190MPH.

 

It has nothing to do with V8s and flatter torque curves and ALL to do with rwd and 60fts.

My miata is also a good example of rwd, low mph but good et. I was pulling consistant low 7.50's @90mph in the 1/8 mile Consistant 1.60-1.63 60fts as well.


Also, to whoever said that .2 in the 60ft = .2 in the end, this isnt correct. I went from consistant 1.78-1.8 60fts down to consistant 1.60s and gained .4 in the 1/8 alone. I believe it comes down to if you are getting out of the hole quicker, by the end of the 60ft you are also moving quicker. I saw my trap speed go up by 1mph as well getting the better 60ft.

Simply put, the 60ft makes a HUGE difference.

 

My old civic ran a 10.6@142 with a 1.79 60' if I remember right. My new toy is a 98 formula that has only made 6 passes so far but has ran a 11.1@120 on motor and a 10.6@125 on 100 shot with a 1.51 60'. The formula feels slow but runs the same time, its .3 faster in the 1/8, .19 faster in the 1000' and .003 quicker in the 1/4. If I can find my old slip from the civic I will post both.

 

i think its alot to do with wtq to , because with my car i allways trap low with good et with out a **** load of power and i got a 3000lb car

so add it up
3100lbs with me
460whp
400wtq
60 foot 1.73
1/8 7.45@98mph
1/4 11.44@120mph

look around at these b16 civic running a 11.4's there traping around 130's with the same 60 foot as me with more whp if the car is over 2500lbs

 

Wrong For example a FWD Turbo 2.0 liter will do 13.8 with a trap speed of 96mph or 14.4 with a trap speed of only 81mph. Were a RWD needs a trap speed of 105 for 13.8! only and 14.4 100mph. So has you can see a RWD will need a much higher trap speed than fwd to get the same timing

 

2 things

1. You dug up a 15 year old topic

2. You are very wrong….. front wheel drive cars will always have the higher trap speed since a RWD car launches harder and therefore gets a shorter track to build speed . FWD has to use speed to make up ground

 

Thats true your absolutely right FWD will trap higher than rwd. What I was saying is FWD with less trap speed can get same timing for example a rwd will need more trap speed. For example a FWD 2.0 turbo with just 81mph can do 14.4 when a RWD need something like 100 mph to do 14.4. FWD 2.0 turbo @101mph =13.6 RWD @101MPH = 14.4

 

no

 

True. 15 year old topic. I remember 2005 when I had a Vortec FMU running 8psi of boost.
Front wheel drive cars get less traction off of the starting line, so they get slower times compared to a RWD car of similar build, however FWD cars reach a higher miles per hour per elapsed time because the horsepower is there, but traction isn’t.
Your first sentence is correct but you contradict yourself in your example compared to your first sentence.
Truth: FWD traps higher (per elapsed time) than RWD. A good example using your numbers would be a FWD can do 100mph while running a 14.4 and a RWD would do 81mph while doing a 14.4. And that would be on slicks for the RWD.
If you watch a race between a FWD and a RWD of similar weight and horsepower on a drag strip, then the RWD will start off winning, ahead, then the FWD will pull on the RWD as the race goes on until near the end when the FWD will either get close to winning by catching up, or just barely win by surpassing the RWD near the end. Like an underdog. If the FWD is Turbo or using Nitrous then it’s exaggerated.

 

I hate to bump this again but here’s my .02. Spinning effectively makes the track longer. Fwd cars spin a lot, so technically they get a much longer track to build speed.