Suspension setup question.

obi_waynne

obi_waynne

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For drag racing I imagine the best suspension setup would be a toe in appoach as a toe out enhances cornering ability. On take off though the front lifts up and the cars weight is thrown to the back so is there an arguement for stiffer suspension and a geometry change for drag racing?
 
I, err, dunno really. I thought that drag racing was really a straight line sport anyway so all you really need is for the front setup to allow directional control under braking. As such I agree that toe in would help as this will get closer to nil under braking.
 
Hi

have a look at:
http://www.aircooled.net/gnrlsite/resource/articles/dragsetup.htm

Lots of interesting tips for setting uo a drag car.

Or, here is the relevant extract :)

Front Toe
For a drag car, you want a TOUCH of toe-in up front; this reduces "scrubbing" (sideways movement of treads against the road). Excessive "scrub" can hurt your MPH going thru the traps. Toe out is twitchy and simply dangerous! 1/16-1/8" Toe-In is a good number to shoot for. When you check and set toe, do it on the ground (not in the air), since toe changes depending on the set (ride height) of the front wheels.
 
waynne said:
You need a little more toe in for FWD cars than with RWD cars as FWD wheels pull apart slightly as you acceleration whereas RWD pushes the wheels together.

Did you read our articles on Drag racing in the Articles section - they cover quite a few aspects of car setup. http://www.torquecars.com/articles/index.php
Click to expand...

Maybe, but why use a FWD car for drag racing? Pretty pointless, if you ask me :)

Item c) Using harder shocks is interesting. Does it mean stiffer springs or dampers or both? I would have thought that any stiffening of the suspension over the driven wheels (talking RWD here) would have reduced the weight transfer under acceleration. Also, stiffer suspension reduces body roll but tyres will tend to skip more, so actually reducing traction IMHO.
 
old-git said:
Maybe, but why use a FWD car for drag racing? Pretty pointless, if you ask me :)
Click to expand...

Not completely pointless.....

FWD is a neat packaging arrangement, and means there's no (extra weight) of propshaft, differential casing, etc, so on a lowish power car, the weight saving more than outweighs the lack of traction. And its really only at launch, or very high power, where this becomes an issue.

Remember also that front engine rear drive means less weight on the rear wheels, especially if you've made efforts to lighten the car. After all there's loads which is removeable from the rear, not so much (without spending a lot of money on carbon fibre bonnet, wings, etc) from the front.

Of course, the optimal configuration is rear engine rear drive; or mid engine (behind the driver) rear drive. eg VW Beetle.
 
paul_c said:
Not completely pointless.....

FWD is a neat packaging arrangement, and means there's no (extra weight) of propshaft, differential casing, etc, so on a lowish power car, the weight saving more than outweighs the lack of traction. And its really only at launch, or very high power, where this becomes an issue.
Click to expand...

Hence the :)

However, in drag racing, the first 60 foot is the most important phase, which is why a RWD car will always beat a FWD car, everything else being equal.
 
old-git said:
paul_c said:
Not completely pointless.....

FWD is a neat packaging arrangement, and means there's no (extra weight) of propshaft, differential casing, etc, so on a lowish power car, the weight saving more than outweighs the lack of traction. And its really only at launch, or very high power, where this becomes an issue.
Click to expand...

Hence the :)

However, in drag racing, the first 60 foot is the most important phase, which is why a RWD car will always beat a FWD car, everything else being equal.
Click to expand...

I suppose it depends on the power, vs the extra weight carried by the propshaft, diff, and the weight distribution front wheels/rear wheels. I've seen small/light cars converted from FWD to RWD and because there's so little weight over the rear wheels, struggle to put the power down.

Basically, is the weight on the rear wheels by weight transfer (due to acceleration), greater than the weight on the front wheels due to the transverse front engine; once you've taken into consideration lightening the car (probably at the rear)?

So while there's one main factor which naturally points to RWD, there's a couple of other factors which go against it.
 
Hi Paul.

Clutching at straws, methinks :)

results from TOTB6
1/4 mile FWD 11.69/128......RWD 10.41/133
Handling FWD 40.85secs......RWD 37.02
Top Speed FWD 169.1mph......RWD 203.9

I rest my case - A good RWD will always beat a good FWD :) Basic physics.

The only reason FWD cars exist is because it suits manufacturers to build them! (IMHO)
 
Yep, pretty much agree. I'm no way near 10s, or 11s for that matter. Once you're getting into that kind of performance (which is well away from most roadcar stuff) you're getting the front wheels into the air.

I guess I'm just hung up on cute little Mk1 Golfs, or something.....
 
old-git said:
The only reason FWD cars exist is because it suits manufacturers to build them! (IMHO)
Click to expand...

They are much safer in corners and have a tendancy for understeer. This is a shame because a bit of oversteer is what makes a car fun to drive. Am I right in saying the 2 CV was the first mainstream production FWD car? (CV = constant velocity joint and the car had 2 hence the name! You really got to hand it to the French for imaginative car names!)
 
old-git said:
The only reason FWD cars exist is because it suits manufacturers to build them! (IMHO)
Click to expand...

is it still not cheaper for manufacturers to produce fwd cars over rwd therefore keeping costs done overall

understand where waynne has came from with the under steer issue. but a lot of fwd still suffer from lift off over steer, which can cause drivers to lose control if there not expecting it
 
2CV was named after 2 horsepower. A French horsepower had the abbreviation CV (from chevaux), except that its equivalent to 8bhp or something. Its to do with the era when French cars were taxed on their horsepower figure.

Citroen produced (I think) the first FWD car, the Traction Avant, back in 1934 or something (v unsure!)

The main benefit is efficient packaging of the engine/transmission, using a transverse engine, which means more interior space for a given overall length of car. For example, the Mini was one of the first big sellers to use it and it had good space efficiency.

I suppose these days, with volume production and manufacturers tending to favour it (at least for small/mid size cars) its also cheaper, but only slightly.
 
waynne said:
old-git said:
The only reason FWD cars exist is because it suits manufacturers to build them! (IMHO)
Click to expand...

They are much safer in corners and have a tendancy for understeer. This is a shame because a bit of oversteer is what makes a car fun to drive. Am I right in saying the 2 CV was the first mainstream production FWD car? (CV = constant velocity joint and the car had 2 hence the name! You really got to hand it to the French for imaginative car names!)
Click to expand...

They are much safer for "ordinary" drivers who have no idea how to control a car, haven't practiced skidding recovery, cadence braking, etc. Fortunately, we on Torquecars are not "ordinary" so RWD shouldn't pose a problem for us :)

According to Wikipedia it means; deux chevaux, literally "two horses", from the tax horsepower rating.
 
Ooopps, sorry paul_c, you have already answered Waynne re 2CV. I really should read previous posts properly before replying.
 
Do I get a point for Citroen :? :D

I've got to agree with the "we on Torquecars are not "ordinary" so RWD shouldn't pose a problem for us" statement.
 
toe slightly out will increase the tire contact area during acceleration as the front tires will pull themselves back to 0 toe position . 0 camber will also stablise your car on the straits and positive castor will also improve straight line stability.
 
the suspension should be stiff all round and the base of the car should be level and the car should be lowered. this will allow you to launch quickly, to change gears without your car bouncing to much and u get better braking stability
 
it will on be bouncy on circuits where roads may not be level. and when u change gears on a straight a stiffer suspension will prevent the nose of the car from diving
 
Not yet. I have heard it makes quite a difference. I tend to use soft tyres like Eagle F1's which cost a fortune but give loads of grip.
 
Lowered suspension might be good at the time of a drag. but, if you carry 3 people at the rear, how will the suspension work. Can you experts gimme any ideas.
Thanks.
 
Hi Bigmoose. It depends how low you go. If the car is an everyday runaround then you need to make some compromises like sticking with a 35-40mm drop. Adjustable dampers will help to give more control and you can get shocks that come with a ride height adjustment so you can alter these depending on what you are doing at the time.

(Welcome to TorqueCars as well mate, nice to have you along!)
 
Thanks Waynne

Mine is a small car. Its actually a hatchback. It has an FFE with header with stock K & N. I am planning for a custom made pipe with a conical filter for air intake in one or two months.

The availability and cost for the height adjustable shock might be a problem for me.

I have already stiffened the front suspension and have increased the height of the rear one. Still if we have 3 people in the back, the tyre sometimes touch the car. The tyre is 195/45 hankook ventus with 14 inch alloys.

Can I lower and will it effect? i dont want the tyre to touch the car. I need real good help. The car is for daily use.

Thanks.
 
I have already done that while I changed my wheels. Do you still suggest me to go for lowering the suspension. I want to be sure that it would not brush the sides. Have you done this to your car. I am not sure if we have the expertise here. Also, how much would it cost.?

Thanks.
 
"Expertise here". I meant in my country to do the lowering. Not you guyz. Sorry if you guys misunderstood.
 
yul carlinsky said:
the suspension should be stiff all round and the base of the car should be level and the car should be lowered. this will allow you to launch quickly, to change gears without your car bouncing to much and u get better braking stability
Click to expand...

Lowering car will increase your ET as it will reduce weight transfer to the rear wheels (the only wheels that should be driven on a drag strip :) )

Experimenting with ride heights with my simulator, the car runs 9.51 at 4" ground clearance and 9.4 with 8" clearance.

Some cars run with with the front actually higher than the back to further aid weight transference.

Too stiff a suspension setup will hinder weight transference.

A lower car will help with stability at the top end, when you eventually get there :)
 
I understand all this. I would like to use it with only the driver on board. The problem is that I might have people in the rear as well sometimes and I don't have another car.

Lowered suspension would be good at the time of a drag. What about for normal use. Would it not touch the sides?. Or is there something that can be done to do it witout the tyres touching the car ever even if there are a total of 5 passenegers.
 
Waynne

Can you help me in posting pics. ??

Need help. does 10 posts makes me eligible to post pics. ??
 
Yup 10 posts and you can now post pics. Use the advanced reply and the quick upload option, or create a new thread witht he quick upload option or go to your profile and create a gallery ;) or you can use the attachments option when you post.;)
 
What would be the cost?. I have seen cars here with the suspension lowered...looks awesome....Can it be done on the original suspension set up or do we have to purchase new ones just for lowering....Will the ride be stiff??
 
Lower does not always mean stiffer. The springs stiffness sets this rather than the height although most smaller springs have fewer coils and as a result are stiffer.
 
just a quick note: weight transfer remains the same no matter how stiff your suspension, what you do by stiffening the suspension is keeping the pressure on the tyres as much as possible
 
Munday said:
just a quick note: weight transfer remains the same no matter how stiff your suspension, what you do by stiffening the suspension is keeping the pressure on the tyres as much as possible
Click to expand...

Hmmmm, don't agree with this. A soft front end is required so that the chassis is tipped back over the rear wheels (RWD cars) under acceleration, increasing the weight acting through the rear tyres. Ideally, you want the front wheels to be just about to leave the ground, thereby transfering the car's whole weight through the driving wheels. A stiff suspension will not allow this to happen.

However, I imagine that this is not so important on a 4WD car and a stiffer suspension may well be required for FWD in order to reduce rearwards weight transfer.
 
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