best handling suspension that maximizes straight line acceleration?

Target platform is a 2nd gen camaro. I'm looking for advice on what combination of front and rear suspension will provide the best braking and cornering but put maximum priority on straight line acceleration traction. One specific question I have is, is there anything about a drag race style four link that would really hurt non-straightline handling? Any vehicles that I have experienced that have a nice four link in the rear also have a not-so-nice combination of stock suspension, stock brakes and "skinnies" up front which pretty much kill any kind of braking or steering. On the other hand, any vehicles that I've been in that have really serious front suspensions and brakes have been IRS and not at all set up for maximum straight line performance.

The application here is a 1500hp turbo small block, so when I say that I need to maximize straight line performance it's not really an optional criteria. As far as the "handling" I'm after, I'm not looking to go run with Z06's and Vipers on the road course, I just want something that is very responsive and confidence inspiring during "spirited" street driving. When I have to get on the brakes quickly, I don't want to feel like I'm plowing through a sand pit, if I have to quickly change lanes or swerve around something I don't want to feel like I'm in an Explorer that's about to flip over.

Any general suggestions on suspension designs would be great, and any specific products designed for the 2nd gen Camaro would be even better!

Thanks!
Jeff

This is a tough one and I wont even begin to scratch the surface...

Here's the big problem I see. 1500HP is an unbelievable amount of power. Unimaginable. If you can feather the throttle enough to keep yourself from oversteering into the grass at every corner, you deserve the Nobel Peace Prize.

1500HP is useless, quite frankly. There is no tire in the world that will allow you to put even half of that on the ground efficiently, especially one that will allow you to turn corners. Do you know what that kind of power feels like? Have you ridden in an 800HP car? 800 is enough to spin 16" wide tires at will at any street legal speed. With that kind of power, this will not be a well-balanced car.

Ok, off my soapbox. Now, this is a car I would go with either a three-link or a triangulated 4-bar, both with adjustable uppers and lowers for increased anti-squat. You'd have to fine-tune at each track to get it to work right, and should 60-ft in the 1.7's if you have good tires.

This type of thing is something I haven't done, so maybe somebody here has.

with that much power you will need to have a VERY adjustable suspension and you will have to take the time to learn to set it for the conditions you will be faced with IMHO you will spend more time trying to make the car work than enjoying it .

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Originally Posted by HiBoost

Target platform is a 2nd gen camaro. I'm looking for advice on what combination of front and rear suspension will provide the best braking and cornering but put maximum priority on straight line acceleration traction. One specific question I have is, is there anything about a drag race style four link that would really hurt non-straightline handling? Any vehicles that I have experienced that have a nice four link in the rear also have a not-so-nice combination of stock suspension, stock brakes and "skinnies" up front which pretty much kill any kind of braking or steering. On the other hand, any vehicles that I've been in that have really serious front suspensions and brakes have been IRS and not at all set up for maximum straight line performance.

The application here is a 1500hp turbo small block, so when I say that I need to maximize straight line performance it's not really an optional criteria. As far as the "handling" I'm after, I'm not looking to go run with Z06's and Vipers on the road course, I just want something that is very responsive and confidence inspiring during "spirited" street driving. When I have to get on the brakes quickly, I don't want to feel like I'm plowing through a sand pit, if I have to quickly change lanes or swerve around something I don't want to feel like I'm in an Explorer that's about to flip over.

Any general suggestions on suspension designs would be great, and any specific products designed for the 2nd gen Camaro would be even better!

Thanks!
Jeff

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:postpics:


Andrew

Thanks for the replies, guys!

Matt, I certainly can appreciate your skepticism about my "1500hp" claim. I know the internet is full of day dreamers that come up with wild claims like this. I can tell you that the first project car I ever built was a 1000hp, full weight '94 camaro that was totally street driveable and ran 9.56 @ 143 on stock style suspension (torque arm) pulling a 1.35 60'. My next project car was a '94 Turbo Supra which made 850hp and retained its 6-speed transmission and incredible handling (upgraded coilovers, sway bars, etc., nothing done for drag racing). My business partner and I built his '95 Mustang into a 1500hp street car. It runs 8.20's at 173mph on Drag Radials @ 3450lbs (pulling a 1.33 60' on the back tires). So yes, I know what the power feels like, and obviously it's not useful when going around a turn, but hey, that's why God invented the boost controller :-)

Maybe I should specify a little more what I'm actually looking for performance-wise. I want a car that will be able to be "turned up" for the drag strip - C16 gas, 35psi of boost, ice water in the intercooler, etc. - and utilize the full potential of the combination, which will be in the 1400-1500hp range. However, on the street, I will be running lesser gas, far less boost and a more conservative tune to yield more like 1000hp. Adjusting shock settings or even positions on the 4-link is completely reasonable, but I don't want to actually have to swap between suspension components when the car goes from one "world" to another. Does that make sense?

On the suspension that you call out, is there a reason why the 60' would be so bad?

Hiboost,
I don't have any doubt you can build a motor that strong. We see motors like that from customers every day now...these days with big turbos and superchargers, it's not very difficult (relatively speaking).

It sounds like to me that you want a car that can run quick 1/4's and still stop and turn like a modern car. If that's the case, get yourself a set of big brakes and a 4-link rear setup, and go for it. Upgrade the front end with solid bushings, maybe a 3rd gen steering box, and some nice street tires. That's the only thing I can say.

No off-the-shelf parts are going to be able to reliably stand up to that amount of power. Be ready to do some work.

As far as the 60's go, I'm just throwing out a number. I actually don't know how you'd be able to put down the power in any kind of street tire that still allows decent handling.

Just out of curiousity, why aim for such a high number? 5 bucks says the car would be more enjoyable and better driving if you had less power. Don't get me wrong, big power is cool. But anything over 800hp is just smoke.

Sounds like it`s gonna be a really FUN ride! There`s no reason at all not to start with a good adj. 4 link out back. The one thing you will HAVE TO CHANGE is the traditional drag race oriented location of the panhard bar. Fab your own mounts,make sure they`re planty beefy and that the rails are tied together with an additional crossmember. Make the bar as long as humanly possible and adj. in small increments for height on both ends. Start with it mounted at the vertical centerline of the rear axle tubes. That`ll give you a reasonable rear roll center height to start with. Up front the 2nd Gen F bodys have pretty mild camber curves and lack the adjustment to get much + caster in their alignment especially if lowered. I`m a little biased but I`d recomend our Street Comp suspension with adj. tubular upper arms and tall stud modular upper ball joints. Get them with the greasable racing bushings. This package will give you more aggressive camber gain for cornering,let you run more + caster with will help the car track straighter and give you more steerign feedback and it`ll give you more suspension travel and quicker action due to the 0 bind racing bushings. We have a number of customers running these parts on 8 and 9 sec. cars with excellent results. Compliment it with Del-a-lum bushings in the lower arms and adj. QA1 shocks all around so you can tune it for the street or track and you should be pretty well set. Then the fun begins,testing and tuning to get all that power to the ground. :) You may want to give RaceLogic a call and talk to them about their adj. traction control systems. Mark SC&C

What kind of tires are you planning on running out back on the dragstrip? What about on the street? Full cage? Interior?

M

Thanks for the additional replies guys, now we're getting to some real "meat"!!

Mark: as far as the power goals, I setup my cars to do boost based on road speed. What this amounts to is, the faster you go, the more power you get, but it is usable power because at higher speeds you have more traction. For example, my Supra, even though its got 18" low profile tires on it hooks up perfectly from 0 - 100mph because the boost (and therefore power) curve has been dialed in to the limits of the traction that I have. I also have an advanced traction control system that monitors speed sensors on all four wheels to determine not only if there is wheelspin but also to know when the car is turning. This allows me to program a max slip % for straight (usually around 15%) and a separate slip % for turns (0-5%). (The comptuer will drop fuel injection events to progressively dial back power and therefore maintain the percentage). We have found that with the drag radials (and even smaller slicks) that a certain amount of slip produces quicker acceleration than backing off the power to the no-slip point. The REALLY fast 10.5" tire cars will "black-track" the whole way down the track. Even the Mustang has 3 stages of boost, one at launch, one that comes in after a programmable time delay and a third that is activated with the cruise control button on the steering wheel. You might not think so, but it actually hooks and MOVES on the street, even with drag radials. We have always had great luck with the BFG drag radials (like I mentioned, pulling a 1.3X 60' while doing a wheelie, you can't bash the tires too much), and from everything I hear the new MT drag radials are a whole other world beyond the BFG's.

So I guess the bottom line that I'm hearing from you guys is, there's no problem in doing a "regular" 4-link setup that uses heim joints and an anti-roll bar? I wasn't sure if this type of suspension would bind up or run into other problems when trying to turn or brake? I know it does a good job in eliminating body roll, what about braking characteristics? If you really put some serious binders on the front and have the rear suspension set up for optimal acceleration, is there a big problem with the back end getting loose under hard braking?

Mean69: definitely full interior - can't handle the gutted ratty race car look... as far as the cage, it will be "Jeff Spec" :-) What I mean is, I will build every possible safety feature into the car right up to the point of making it totally painful to drive on the street. In other words, definitely a full 12-point cage, but almost certainly it won't have things like "X'd" door bars with funny car cage around the driver. That means no official chassis certification for running low 8's/high 7's at the track, but if that makes the car that much more enjoyable and actually allows me to get out and drive it on the street a lot more then it's more than worth it IMO.

Thanks!
Jeff

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So I guess the bottom line that I'm hearing from you guys is, there's no problem in doing a "regular" 4-link setup that uses heim joints and an anti-roll bar?

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Actually, a drag style four link using heims WILL bind in roll, it is not as dramatic in seat of the pants feel relative to the drag style ladder bars, but it will bind nontheless. Both types of systems are overconstrained in roll situations, by design. The only reason either of them will actually roll is because something, somewhere, is bending, stretching, etc. Going with a compliant suspension bushing on the control arms will improve things a bit, until you get to the point where the bushings are fully compressed. This has nothing to do with the "diagonal bar" that is used to locate the axle laterally, the guys already pointed out that replacing that piece with a good Panhard bar or equivalent lateral locating device is essential and can make the car a bit more drivable on the street.

We are about a week away from releasing our three link kit for Second Gen F-bodies (70-73, later cars may need additional modification due to floor pan differences), and this could be a really cool solution to your car. I asked about tires, our design has a relative deep scrub dimension (lowest point on the axle) that requires 17" wheels in order to not be the "low" point in case of hitting a curb, etc. Not sure what the drag sanctions require, we are looking into it, but what you describe sounds like this is not going to be a fully compliant car, so this shouldn't be an issue. The prototype is being installed in my own 70 project car, the rear suspension should be complete in a very short amount of time. We changed a few things in the last couple weeks to better allow exhaust clearance for tailpipes, we use a slightly more complex device called a Watt's linkage to locate the axle laterally and it takes up a bit more room than the simple Panhard bars typically do.

Sounds like that car is going to be one heck of an animal, let me know if we can help. Our website is (still) under construction, but I can shoot photos over via e-mail if you are interested, just drop me a pm. Boost controlled traction handling, now THAT is cool.

Mark

I hate to confuse the issue for Jeff and I certainly don`t want to take anything away from Mean`s 3 link project (from what little I`ve seen it looks to be quite well thought out and high quality) but I have to disagree with parts of the last post. A *properly set up* parallel 4 link will have no binding issues within the range of movement we`re concerned with here. We`ve installed many of them and you can flex them very easily to a MUCH greater extent than you`ll ever need on a street car.
I`m not a big fan of heims on street cars. In our experience they`re plenty strong but they get buzzy and annoying in a relatively short time. Since this car isn`t going to see a huge number of street miles it may not be a real world issue though.
Overall I much prefer a well designed 3 link with a good PHB or watts linkage setup on a car built primarily for handling. We designed and built our prototype system 3 years ago and have been real world testing and improving it since. I like it a LOT. But a 3 link still wouldn`t be my very first choice on a 1500hp drag race oriented car.
As for rear wheel lockup,that`s more dependant on how you have the 4 link (or 3 link) setup for antisquat. If you run a grea tdeal (drag racing) you may have lockup issues but it`s also dependant on the weight transfer of the chassis. So the rate of the front spring,shocks,% of anti dive etc. also play a part. We`ve found we can run well over 100% antisquat in the rear with no rear lockup (even in the rain) provided that the front is stiff enough (700lb/in springs and adj. shocks set fairly firm). At a certain point large amounts of anti squat begin to cause some handling quirks when cornering though so again,testing and tuning with *your car* is the only way to really determine *exactly* what will work for it as far as adjustments and setting go. Mark SC&C