Well, i've got to a point financially where I can start putting more money into my car. Its a 91 a4 L98. Slow as heck right now. Took it to the track a week ago and ran 14.3 at 95mph. I'm still fairly young and know abit about modding cars in general but far away from an expert. And I want to make my car faster, but I want to do it the right way, not buy some part that "I" might have thought to help but later learn it doesn't do jack crap. So I was wondering if you c4 guys could tell me what should I do with the car for the first few mods. All it has right now is exhaust(straights) and a transgo shiftkit. Here's what i have kind of been thinking myself: Mabye an intake, headers, throttlebody. I don't know. I don't really want to change the rear end gears yet, (b/c i would have to pay a mechanic), but mabey I will. So i guess if you guys could help a new kid with some needed advice on what i should be investing in, and what not to, and mabey other advice on building my L98, I would greatly appreciate it. Oh and another thing nitrous probably is really a bad idea for my car right? since its like 13 years old and has 98k miles on it?
Thanks in advance for helping me out, sorry if I am buggin the **** out of everyone by asking all of this, hhah.

 

I have a 90 and what worked well for me was cut lid air box that you can do yourself, and remove the freezbie that is attacked to your water pump. These would be a good start.

BTW You said you have straight exhaust. Do you still have the pre cats on your set-up?

 

dont, know to be honest, i need to get under my car and check, ive only had it for two weeks. I was just told by previous owner it was straights...

, oh and also, what are some good places to find/buy performance parts for the L98?

 

Another good improvement is a set of long tube headers. L98 really like long tubes. A good set of plugs, wires, and coil. As for parts try Summitracing, Ecklers, MidAmerica. On the automatic car 3.73 gears will really make a difference.

 

Depends on how much you want to spend If it already has "Straights" it may already have some stuff done. 14.3 sounds a little slow to me if it already has a few mods...A plain tuneup may be in order.

 

The L98 responds well to intake\exhaust mods. Trash the trottle body idea and don't buy an airfoil. I will be honest... I am partial to them, but others on here have proof that they are as good as a paperweight.

I am also partial to TPIS. I had a 91 Trans Am with the tuned port motor and was spanking LT F-bodies with it and at the time it was only a 305... I later dropped a 350 in her... but had to sell her. I bought all my parts from TPIS and was very pleased... however, others on here have been hurt by them so pick your poison wisely.

Unless you got the performance package... you are suffering from the 2.59:1 rear set up. Gears will kick you in the pants pretty good.

For intakes... this is the catchy part I mentioned above. I had the TPIS bigmouth on my TA and was very happy with it. I opted for the Edelbrock runners because I got them cheap on ebay... but any good runner will do. Another thing to consider is scoring a set of the Vortec heads and intake from Scoggin Dickeys. That is a cheap and effective way to make some power.

After my experience with this motor. I would recommend a long tube header with 1 5\8 primaries. I had the 1 3\4 on my car with a 52mm TB and it didn't wake up until I hit 3200rpm... it was like driving a V8 Honda. I didn't like that, but once the power curve hit... I was off and running with the best of them.

Nitrous won't really kill your motor as longas you use it in moderation. N2O is a fun thing... and if you have the $$$ for a new motor...blow the thing up with some laughing gas. This gives you an excuse for a 383 or larger!!!

 

That time isn't bad for a nearly stock L98 with A4 and 2.59s.

Your time will really benefit from a 2,000rpm TC; I think your stock is 1,500rpm.

Yes full exhaust mods: LT headers, hi flow cat and good cat back will really wake it up along with a cut lid with K&N air filter.

You will also need an AFPR to add a little fuel as you go.

Losing the frisbee is worth 10chp, installing a 160deg t-stat and fan switch will bring a nice gain as will cut-back stock AD Delco spark plugs.

You can port and work your stock heads for a 30chp gain and a good cam will bring similar gains.

For the intake you can do the Accle base with either AS&M LT runners or with the SR intake. The choice depends on your choice of where yoiu want to add torque.

Once you have finished air flow mods you will likely get some gain from a custom chip.

There is a recipe on my site for getting to about 370chp with a '90 Vette L98.

 

I have a 91 with straight pipes too and 90,000 miles. Check my sig for the mods that I have done. I have just a few and my best so far is 13.4's. Good luck. I had to practice my launch a bunch of times to get it that low.

 

 

14.3 may not have been to bad if all he has is straight pipes. 60 ft times would help to see how much tire spin you had and to see how strong it is running

 

my 60 foots were 2.1 on average. Im pretty confident the straights is the only thing done to the car, since I know all previous owners, except for the first.

What about loosing the cats completely. Bad idea? I've heard this can burn out the oxygen sensor, but not really for sure if thats true or not.

 

The cats on that car should be good to handle 450+hp without serious restrictions. I'd recommend getting a Random Cat or a Dynatech cat. They aren't too pricey and allow you to remain 'legal'.

That 2.1 isn't bad!!! If you can get that down to a 1.9 or 1.8... you are looking at a 14 falt or maybe a high 13!!!

 

i guess i could just replace that cat with a better flowing-cat. but just completely removing it still ponders in my mind... I live in OK and they don't currently do car inspections, therefore i could get away with things like no cats. well at least for now... So do you think removing the cats completely is stupid, or would help for sure? or what do you think?

 

As others have suggested, intake and exhaust mods are where its at on an L98. First though, I'd make sure the car is properly tuned up because I think it should be running a bit quicker than it is. I'd expect your mph to be around 100 or so with your trans and rear.