Najania

Hi there.. I am going to attend a drag show here in my country. but i dont feel my Corvette is fast enough to compete without getting a bad placement in the tournament.

It is a 71 corvette weighing in at 3200lbs. I have equipped it with a brand new LS2 and 4L65E, both using controller kits from Gm as well. The rear end is a 3.08.
My g-tech pro ss says the car runs 0-60 in just under 5seconds, but dont know yet what the quartermile will be though.

Please give me some ideas to what i could do to make the car faster without tearing the engine apart.
Im thinking underdrive pulley, headders, maybe a different engine control unit. Better tires(currently running michelin pilot sport 275/40/17) different rear end ratio maybe. Im already running a KN cone filter btw.

Please chime in with some ideas

I have only driven 500miles in the car yet, with 3 months to go before racing so im still not finished breaking the engine in, or what you call it.

Thanks in advance

iansane

Driver mod.

GTOSE

iTrader: (1)

N drop it.

Project GatTagO

iTrader: (7)

I would guess that with some practice you should be able to run in the high 11s.

Andrew

Stu Cool

iTrader: (13)

I think you are going in the right direction with your ideas. I suggest, lower gears, about 3.55 or 3.73, a higher stall converter (3000 range) and some sticky tires, either slicks or drag radials. That will make a huge difference and still be very drivable on the street. Then practice getting it launched with minimum tire spin.

Glad to see classic American cars, especially with LS conversions over in Europe!

Pat

V8Rumble

iTrader: (9)

Very cool, that sounds like a really sweet car you have there!

I'm slightly surprised that no-one's mentioned weight reduction yet. I don't know how much is possible (or practical) for you, but you can usually lose a fair bit of weight by just expending some time & effort. (And as an added bonus, lower weight cuts down on breakage as well.)

Do a bit of research, & find out what kind of suspension modifications work best for your car. I don't know a LOT about Vettes (especially the earlier ones), but I DO know that a lot of drag races are won & lost on the starting line - been there & done that... Suspension tuning can be HUGE since all the power in the world doesn't help you win if you're just making a smoke-show... (Although the crowd usually likes it!)

Make sure that your air filter is drawing air from somewhere other than under the hood!! I've seen articles that have claimed to have gained over 20 horsepower (roughly 15 kW) from simply drawing the intake air from a fresh air source, rather than anywhere in the engine compartment. (And THAT is nearly free as well.)

This tip won't make you any faster, but it very well COULD save you from the embarrassment & expense of having to be towed away... Make sure that you have an auxiliary transmission cooler plumbed in. I've heard that you greatly extend the life of an automatic transmission with every 20* F (approx. 7* C) drop in fluid temperature, & racing will only increase the difficulty that the transmission is facing. It's not that difficult or expensive, & it could help save you from an embarrassing & stupid end to your fun.

Deeper gears & better tires are also a good idea, but without practicing your launch & shifting (the previously-mentioned "driver mod"), you probably won't get the full benefit from them. It might very well help to have some way to record your runs so that you don't have to fall back on the old "Well, I think it felt quicker..." When you make any modifications to the car, or change your launch/shift technique, try to either have someone timing/recording you after you've noted what the changes were, or perhaps use something like a G-Tech to keep track.
(EDIT: Just re-read & saw that you have the G-Tech, so with some careful logging, you already have that part covered...)

There's probably more that I'm forgetting, but that's a decent start. Check this group of forums for more info, especially this one. Best of luck, have fun with that beast!

You now owe us two things:
(EDIT: One last thing - using the calculators on this page can help you, especially when choosing which ratio/set of gears to buy.)

Best of luck!

Najania

I have already lightened it quite a bit. I have removed the pop up lights with monza style headlamps. Lighter engine, removed the power steering. Dunno what it's called, but i have removed the entire ventilation system of the car, since it doesn't get that warm in DK, and I only drive it when weather is good. aluminum radiator. The entire suspension have been replaced with lighter triangles both up and down, glasfiber leaf springs front and back. aluminum wheels, ssbc force10 extreme 4piston aluminum calibers. Probably a couple of more i can't remember right now.

But V8rumble you make a good point. very helpfull.. Will try and add cold air from the outside. Save up money for a converter. But i already have a gtech pro, so it records my times. Just haven't had the opportunity to fully test it yet.

I have already added a transmission cooler right in the front dragging in cool air. I have a rebuilt 3.42 rear end lying around to use also. But i think the tires are my biggest concern right now. If i dont let off the gas when it shifts in to 2 it will srive sideways down the road.. Can't stress how happy i am with these new ls engines.. Had a 509 earlier and this is, by far, more fun in the long run.

Will look into the links you posted.


Here a vid of the car reving
http://www.youtube.com/watch?v=JFP2S...e=channel_page

pics
http://s379.photobucket.com/albums/o...=untitled1.jpg
http://s379.photobucket.com/albums/o...=untitled2.jpg
http://s379.photobucket.com/albums/o...=untitled3.jpg

The event is called DHB.. In english it stands for; the fastest car in denmark.

V8Rumble

iTrader: (9)

Oh yeah, that is a sweet car...

Long tube headers (if they're available) should give you a solid 25 hp. (Maybe that would let you get sideways when going into 3rd...)

Another thing that I noticed when looking at your pictures - if you're able to, see if you can get at least a short length of straight tubing on either side of the MAF sensor. That should keep the great majority of the airflow going in a single direction, which (I've heard) will make the MAF's readings more accurate. (Probably not a HUGE factor, but every little bit helps, right?) I can see that you don't have a lot of space there, so if you're not able to, you'll probably be OK.

BTW, Andrew was pretty close with his guess - here's the output from one of the elapsed time calculators I've found:

I guessed 430 HP, weight at 3150 lbs, track elevation at 650' above sea level (which is probably a bit high), temp at 68* F, & relative humidity at 72% (totally guessing with that last one).

Should be a lot of fun regardless.

Najania

Wow.. Thanks alot. Cant wait to see what times she'll be pulling. I have found out another way to route the intake getting in cold air only. Lenghtenen the intake tubing and directing it straight down between the radiator and subframe connector(or what it is called) building a small box protecting it from the radiators heat, but with a lip on i directing the cold air form under the car straight to the filter.. Either that or i will have to lower the radiator, modify the frame stand, moving the electric fan, and buying a corvette c6 intake to go over the radiator frame.. The first way will be the cheapest and what ill start with.. Then the maf will be better placed.

I heard somewhere royal purple oils add a little extra hp.. true?

Will try and look into those full lenght headders.. Are not completely satisfied with the exhaust anyways

found out the rear end ratio of my second rear end is actually 3,73... nice bonus.

Thanks for the great help so far. Will try and measure my times when the weather allows it.. Maybe it will tommorow

Najania

Well. Took the car out for a spin with the gtech pro.. The car ran 0-60 in 4.4seconds

But the quartermile was just 12.90 with a trap speed of 98mph
I know 12.9 is a decent time for a 500mile stock ls2 but my trap speed is that good or bad?

I will change the rear end this weekend from 3.08 to 3.72 and try and see what times will be then.

Cannot change the air intake before the parts shop open again so i'll wait changing that.

jomomma

iTrader: (39)

your gear is killing your mph. id put in those 3.42 gears, put in a 3000-3200 stall and get some good tires. that should give you mid 11`s easily. headers and a good tune would be icing on the cake!

Najania

I have now succesfully changed the rear end after alot of work. I actually did it twice, since after the first install the rear end made a constant wine when coasting/decelerating. So i took it all apart again and thried shimming it over again. Didn't help. Just came back from a series of run. Still whines. Very irritating.

Anyhow, the car pulled 0-60 in 4.23, and did a quartermile of 12,69 with 114 trap speed.
I was expecting to do better actually so im a little bit dissapointed considering the amount of time i have invested in the change versus the gains it has given.

Any ideas why the car hasnt made a better run?

And what will the effect of a 3000stall converter be? When i launch i let it roll for a split second before i WOT the car. If not it will spin the tires through 1'st gear. Will the new converter not just make it more difficult launching it without spinning the tires?

And what gains can be seen from a headder and cold air intake in the quartermile?

Alot of questions, I know, but im a newb to the drag racing scene

Stu Cool

iTrader: (13)

You are making the right moves, but without better (sticky) tires you will not be able to take advantage. Some good drag radials or slicks will make a huge difference and then the higher stall converter will help. You can see by your improved speed that the gear ratio change really helped, but I expect your 60 foot time is suffering. How hard will it be to get the tires over there?

Pat

Najania

Not hard at all.. I can internet order just about anything. It's money that is the issue. im a mechanic apprentice so the money falls short far too often I will try and save up money for some Nitto's and LSx headders from SpeedHound. Will make my own CAI the next couple of days after work.

I have heard the LS engines have to drive a certain amount of miles before they perform at their maximum. Is there any truth to that?

And is 12.69 a good time considering the "hardware" in this car?
I'm sure with a lot of practice I can make it faster. Maybe 12,5 at best.

SilverBullet73

iTrader: (2)

Converter will make tire spin worse, you need some sticky tires to fully take advantage of it. Headers and a good converter will really wake your car up. I'll use my car as an example. I ran an 11.95@114 w/1.755 60 ft time,at a sea level track, 30 degree temps(serious traction problem I might add) with only boltons! My car weighs about 3700-3800 lbs w/driver. With your lighter weight, you will be faster provided you can put the power down to the pavement. My mods are, Hooker Fbody 1/34 inch long tube headers, 3 inch x-pipe w/cats and Magnaflow mufflers to 2 1/2 inch tailpipes(will upgrade to 3 inch at a later date), 4 inch intake pipe drawing cold air from the lower fender area, SLP underdrive pulley, 2800 stall vigilante converter w/ rebuilt 4l65e trans, Ford 9 inch with 3.89 gears, BF Goodrich drag radials(now upgraded to Mickey Thompson ET street drag radials) and a good dyno tune. Motor put down 365hp/367tq on a dynojet. This combo made my car very torqey and it's very streetable. This is just an example of how little it takes to make these LS motors fly!! And now I say, happy modding Hope this helps.

Najania

Absolutely.. It helps a great deal. Now i know what to do, so i'll have my work cut out for me. Thanks for the great help so far silverbullet, jomomma v8rumble and stu cool.

Found out it costs "only" 2grand to buy nitto's, tci converter, lsx headders. though, I will probably have to buy a new engine control unit to be able to tune it. People are saying GM ECU from the controller kits cant be tuned. But that won't be in the near future.

NoRotor88

iTrader: (5)

If money is an issue, buy a good set of tires and the converter. I wouldn't worry much about the headers with a stock engine. You will see the best gains from the tires and converter.

Just my 2 cents.

Good luck, sounds like fun!
Jesse

SilverBullet73

iTrader: (2)

Definitely if money is an issue I would do the tires first then the converter. You may need someone to tune out possible codes you may get from the converter. I got a code from mine when I first took it out on the road. I can't remember the code number but I know it was "excessive slipping" that caused my trans to go into limp mode only grabbing 3rd gear. The looser converter causes more slip in the trans and the computer will see this as out of the normal. The tuner just needs to turn off the code. Make sure you get a trans cooler also if you don't already have one! It will help with the extra heat the converter will cause.

Najania

Im gonna go with the tires for sure. I currently drive michellin pilot sport but they're at least 7years old(but amazingly still has a fair amount of thread on them) so im thinking they don't have the same grip as they're supposed to. So im gonna buy a set of nitto dr's for starters. Converter will come later.. I want that 11 second club tag next to my name

Najania

gotta love those LS engines superb starting point for some serious fun.. Drag racing is addictive