What would be the best setup on a 1994 for straight line performance?

 

Doesn't matter the year C4, solid rear axle (typpically 9" Ford) will be best option for straight line performance.
Aaron

 

Hmm. havent seen that swap done. At what point would one require a 9" and what other suspension mods are reccomended?

 

No question, for a 10sec and faster car.

But a Dana 44 and an automatic can last to high 10's.

Other than adjustable shocks and 3:54 gears I am running a stock suspension,

 

Which brand adjustable shocks? Also what else can be changed? I guess the only other things would be the sway bars correct?

 

I don't know what it's going to take to convince ya'll that a D44 when properly built can go well under 10's... I've got three customers right now on the cusp of 8's with short times in the low 1.20's...

Anyway, drag racing an IAS car takes some work. Those of us that do it have paved the road for many to follow. Suspension alignment is critical with these cars... Sticks like 2-2.5 degrees of POSITIVE camber, autos tend to do best in the .5-1.5 range... You don't EVER want negative camber: when the car hits the tires it pushes them out in an arc. With negative camber you lose a HUGE amount of contact (you'll be trying to hook on the insides of the tires); with positive camber they will flat track and give you a complete contact patch. Remove or disconnect the front swaybar, add adj. heim joints to the rear swaybar so you can preload the right rear. GOOD shocks are a must if you're serious... At the very least a set of 90/10's up front (Competition Engineering has some inexpensive ones) or even better a nice set of double adj. Strange or QA1's... Weight transfer is critical (to a point).
-Jeb

 

Great info. Do the make a rear drag bar for the Vette? Also would it be benificial to convert to the shock/spring conversion setup for drag racing?

 

I do use a coilover setup on mine but have a couple of customers running bottom 9's with modded transverse spring setups. Nobody makes a good adj. swaybar (drag race style) for the C4's but the universal ones mfg'd by Competition Engineering, Chassis Shop, Alston's, S&W, and others can be utilized in a C4 chassis with some work.
-Jeb

 

Jeb,
I totally agree with you with the exception that from a mere simplicity factor and more importantly, durabilty, the removal of the IRS in strictly drag racing applications is the better choice. The camber issue disappears. The other advantage is that you end up with essentially a "short" four link suspension. Now you can load the rear with the links and/or the coil overs if you chose to use them instead of the transverse spring. Given that I am required to use the transverse, not afforded that option.
As far as shocks, I have been using a double adjustable Koni coil over with the coils removed very effectively. 60' in the 1.30s with a NHRA stock class L98.

 

Damn, I wish I could get my 60' back to the 1.5 range and here you are in the 1.3 range. Can we get some detail as to motor and trans set-up?

My comment on the solid rear axle is as discussed above. For a pure drag car, I think the straight axle is far easier to run quick. With that being said, I am still running the cryo treated D44 on my car.
Aaron

 

The engine as I said before is mild by most of the engines I see here.
http://www.nhra.com/tech_specs/engin...ts/CHEV-90.rtf
Basically a L98 with a stocker grind cam and headers. I use basically very loosely!
The transmission is a Scott McClay Engineering Turbo 200 with a A1 converter.

 

Dude...I'm in COMPLETE agreement with you. I've never been of the opinion the IAS is optimal for drag racing. There's too much parasitic loss through the geometry, you have to deal with camber and toe issue that aren't preset on a straight axle, and many other factors... However, not only can an IAS be made to hook EXCEPTIONALLY well, it will take an obscene amount of abuse when built correctly. Is it the best? No... But is it cool (and funny) to look in people's faces when you just clicked off an 8 or 9 second ET and tell 'em, it's still got the "independant" in it??? HELL YEAH!!!!! Plus it makes me money...
-Jeb

 

With IRS, my biggest fear is twisting the halfshafts. they would go before anything else.

 

Still Jeb, this is more the exception rather than the rule. I have seen what low 10's can do to new u-joints after only 10 runs.
Yes, you can have an IRS in 8's & 9's, but I doubt an average racer could maintain or would want to maintain it.

I maintain my previous statement - so we agrea to disagrea.

 

What about the C-beam?
It's aluminum.
What role does (or could) it play in the big picture of a drag IRS set-up?
Can any improvement be had in this piece?
I thought I saw a couple of fellow forum members here fabricate a new version C-beam out of ________?
(steel???)

 

after 2 years of breaking nearly every component in a bottem 10 second ride i decided to slow her down 1st carriers ten replaced that with a spool prblem solved then half shafts drive shafts inner and outter spindles and close to a hundrud u joints at $25 a pop i gave up and slowed the car down a little and am much happier beside the spool is no fun on the street believe me


save your self the time and money and put in a solid rear for anything faster that mid to high 10s just my 2 cents

 

i have never understood this. why would anyone ever convert a corvette to a straight axel? you do realize that GM made a car with a corvette engine and a straight axel anready in it.... they named it Camaro. if you want a purpose built drag car with a straight axel and a corvette engine L98, LT1, LS1 pick your vette engine it doesnt matter, build a camaro. is there something i am missing?

 

The IRS can be made to "live" down in the low 10s - been doing it for 3 years now, but the maintenance costs are high to keep it there - don't fool yourself into thinking it's not. I have gone through u-joints in the matter of 1 run before. Not just one, but ALL 4 completely chewed up. Basically it grinds the needle bearings up to powder and the caps fail. If you don't catch it in time and make a run on a bad cap you will then pay the piper by getting to replace the beaten stub axle pocket.

Again it can be done, but EVERY time out be prepared to be replacing stuff or having your day cut short by a broken component. The U-Joints are the WEAK link in the setup - not the 1/2 shafts. I have only twisted up two 1/2 shafts in the last 6 years racing and hundreds of runs down the strip. And I always replace with used ones that came out of who knows what.

Not to mention the IRS is not the best for distributing power, there are angles involved and power is and will be robbed, its MUCH worse than a bad set pinion angle on a straight axle setup - because you can't get the launch optimized and the downtrack at the same time. '

Hooked up's car is a prime example of what you can do when you install a straight axle in one of these cars. Maintenance free for years going from high 1.3s to 1.28s in the 60' range.

For me going to the line and staging without the worry of breaking something is paramount. Unfortunately for me I struggle with spending 7k on a straight axle conversion - when you see ALL OUT DRAG cars completely setup being sold "rolling" for around 10K- and they weight about 2200lbs with driver. Put my motor in one of them and let it eat into the low 9s all day. Now with twins on the way, on the brink of buying a new home; neithers a good option So I will make the D44 live another day.

Again don't get me wrong, for the average racer who hit the track a few days a summer the D44 would be fine, but if you plan on running a points series or pounding it every weekend and have the funds to put a solid rear in - by all means do it.

To make a D44 live you need a min of the spool, good setup geometry so on launch your tires plan flat and some track time to get it all dialed in correctly.

 

Just to add to this, Neverlift sells a 12 bolt solid axle conversion. I believe Leo said it was available as a kit to self install or he would install it for you. He also had a option of using racing brakes or adapters to use the existing corvette brakes. John Mackey has this setup in his car now.

 

Try these link, The first is his homepage, the second is his link to his and a couple of others who has put a 9 in a vette.

yedi

http://www.bowtye8.tzo.com/bowtie8/
http://bowtye8.tzo.com/bowtie8/corve...20Ford%20Rear/