i have an 88 iroc with an l98, 700r4, and the borg warner 9-bolt posi. i ran my car at pacific raceway this past season and my best was 14.7 at 96mph. my car is completely stock but i have a little bit of money to put into it. my question: nitrous 100hp shot, headers, shift kit and 3.73 gears. how much will this help me quarter mile. and has anyone found gears for the borg warner? i heard theyre almost impossible to find. any imput appreciated.

 

If you're going to use the nitrous then you don't need to change the gearing. You are going to need some good rear tires though.
With the good tires and a 100hp shot you should gain around 2.0 seconds and about 10 MPH if you're using the nitrous right off the line.

 

If your car is completely stock. I am going to suggest what about 95% of the people on this board will tell you... Start with headers and exhaust first.

 

I don't think the lower rear gears will help you out all that much. TPI 350's already have a generous amount of torque down low so you really don't need big gears unless you run slicks all the time. LCA relocation brackets would be helpful though. Instead of spending big $$$$ for Borg Warner gear changes, why not get a higher stall TQ convertor?

A higher stall TQ convertor should chop off a few tenths right there. The L37 4.3L S10 convertor (same as the L98 Vette) is good for around 2150rpm in the L98. SLP makes one that stalls at around 2400rpm. Both convertors should be good for at least 1-3 tenths reduction in the 1/4 mile and 0-60. You can go to a higher stall 9" convertor for even better gains, but I'm not sure how that would affect the driveability on a mostly stock car.

A good 1 3/4" header (ceramic coated), mandrel bent Y-pipe and a full 3" catback exhaust will be the first thing most people here would recommend.

 

ok thanks

 

Get some sticky tires first. You can put all the bolt on suff you want but if it aint gettin traction your just spinnin and that dont get ya nowhere.

 

Thats the main thing you need to get.

Forget the Nawws. You wont need to bottle feed a 350.

After tires Get basic bolt on upgrades Headers, better intake, portNpolish.

Than tranny shift kit.

Lose weight both driver and car.

With that you will have a better run.

Did you happen to have the weather recorded that day you where raising hell in the 1/4?

Think Simple!
make sure them slicks are nice and warm

 

I would like to give a different opinion, all of yall who say that the gears wont help much, should first be asking what he has in the rear. If he has 2 series gears then yes gears will help a ton. The 100 shot will be beneficial all around. The headers will help tremendously, and instead of getting an entire exhaust system, i would leave it stock and get an electric cutout. This will allow you to run open exhaust when at the track, and a full stock exhaust when on the street. Dont get a shift kit, they are a waste of money. If you are going to do that, find a good trans guy around you, and have him raise your line pressure, and possible put in larger boost valve, and a wider band. Also ask him to block off your 1-2 accumulator, this will give you one hell of a first second shift.

 

I was assuming he had around the 3.27 ratio.
Even with a 2.77 experience tells me that with a good converter the highway gear will not hurt performance when on the bottle.
Nitrous normally moves your optimum shift point down a little. The lower the RPM, the more power nitrous makes. The horsepower added by nitrous stays very flat, but the power/torque is much more in the lower RPM.
More gearing just doesn't take advantage of this with a street engine.

Sounds like you have a very good understanding of automatic transmissions, but experience with nitrous would keep myself away from the accumulator mod or anything that makes the shift bang harder. A quick shift and higher pressure is great, but making it hit harder will send you into the wall or off the road when on the nitrous. Making the shifts bang is just for breaking the tires loose. The original poster may actually be going for this effect... who knows?

I'm sure your input was appreciated.
I just wanted to add some things to think about since you brought it up again.

 

I agree that if he stalls his car out he would be fine with those gears, but our friend doesnt seem to really want to go that deep into the car. I doubt he would be willing to unbolt and slide the tranny back, and swap convertors. I am personally not a big fan of stalling the car, because tpis are notorious for that low end torque and a very short lived powerband, dieing at around 4500 rpm. If he stalls the car then he would miss alot of his power. I suggest 373 gears with a stock convertor, maybe a very very small stall. The exhaust is going to be a big big thing if you run nitrous, because nitrous allows you to burn more fuel. If you do run a 100 shot, try to free up the exhaust more than just those headers. And 305sbc, you are right about the breaking the tires loose, but all a shift kit does is raise the line pressure for a firmer shift. I just ran out a list of the easiest mods. If he wants a great shift, thats fast and firm but not deadly.....get a diesel govenor for your tranny, and adjust the tv cable as tight as you can get it, this will provide very firm and positive shifts, without killing your traction, this will also move the shifts lower, cathcing more of the powerband instead of hitting the dead spots after about 4500 rpm.

 

Exhast mods will help your nitrous and you will need sticky tires and LCA's to hook up on it. TPI cars respond AWESOME to the juice when you set it off low. I agree with the 2 second drop. I took almost a full second off on my nitro runs and was running out of gear at the 8th from spin, would just let off the juice and ride out the run. Headers and a good flowing exhaust will be a good mod to do after you get the nitro setup.