OK, I'm taking opinions on what my next 1-3 mods should be. The victim is my 97 Z28, automatic. It's a street car that goes to my local strip's streetcar night, current best run of 13.63 @ 103 with a 2.07 60' time. I'd like consistent 13.50s or better without any real driveability loss. Runs best shifted at 6100ish.

Current suspension mods- Konis, Strano bars, 17x9 Z06s, tubular rear trailing arms, SFCs, tubular K member, poly torque arm mount, 98-up front brakes, carbon metallic pads all around. I'm very pleased with my ride and handling. The chassis feels sturdy, predictable, and ready for some more power.

Current mechanical mods- 4.10s, auburn pro series, SLP headers, ORY, magnaflow catback, LT4 module, K&N CAI, and a hypertech (gear correction, shift firmness, rev limiter). Valve covers have never been off, haven't even done the TB bypass mod.

Here's my thoughts at random, on a few of the popular parts.
*Professional Tune- I know I need this, but am putting off because it's a hassle. I'd have to track down a junkyard ECM and send it off, and I lack a laptop for updating. It needs to be done because I live with an EGR code from lack of backpressure.
*MAF or Throttle body- Experts say no gain, but people keep buying them.
*1.6 Roller Rockers- Seems worthwhile, but not sure what I'd actually see at the track. And if I don't tune it for them, is it really a gain.
*Looser Converter- Not sure I could take advantage with street tires, and definitely a hassle to install
*Injectors- It's had a funny idle misfire for years (60K+), thru 2 optisparks and plug wires, I suspect an injector has been sticking. No codes ever. Would I really see a gain from larger or different injectors?

Here's an interesting tidbit. The catback was the last thing on the car. It was running consistent 13.70s with headers and the ORY feeding the stock muffler. So I only gained a tenth with the catback, which is not what most people report. The whole exhaust, headers to catback only netted me 0.2 total. I think that indicates a fuel or air delivery issue.

What would you do if it were your car? Thanks for reading

 

I would get some Drag Radials to help cut that 60ft down a lot.

 

How are those 4.10's on a stock cam, is it overkill? I thought about a 3200 stall, 4.10 gears combo. Why can't you just send in the PCM you have now and get it tuned, it will take a few days. You don't need a TB or MAF.

I ran a 13.4@103.57 with my mods and an A4 with street tires. LT headers and an ORY should net you about .4-.6 depending on how your car responded.

 

Professional tune is definitely worth the money. PCMS4Less or Madz28.com are two great mail-order tuners. I had the same EGR problem, Madz28 was able to do an emissions compliant EGR tune where my EGR functions properly with the addition of long tube headers.

 

with gears that large a stock cam and stall are really limiting your e.t.

 

You did not get the gains you expected from your exhaust because you dont have a tune.

I'm pretty sure Ion can send you a tune in an ECM allready, just send him your old one back when it arrives. That and a nice 2800 stall will make you smile!

 

I chose 3.73's with a 3200. Should be a lot better. A 3200 stall with my car isn't over kill.

 

Allright, allright, I'll get a d@mn tune. You've shamed me into it.

OK- several people have recommended a converter. I've had several older cammed & converted cars, so I think I can predict what will happen. I'll blow the street tires away even worse than now. I'm trying to reduce my ET, but the idea is to run the same ET on my way to work. Does anybody else run street tires that has actual 60' times before and after converter swap? Drag radials on 7 5/8 ten bolts scare me. You have no idea how many of those tiny tens I've broken in other body styles. Probably somewhere in the teens.

blind527- the 4.10s are a little deep, but I broke the stock stuff, and couldn't bear to only go 3.73 for what I was spending, it was factory 3.42. (happened outta town, had to pay full price Ouch!) Hindsight, 3.73 woulda been a better choice, because I love high speed driving. 4.10s conquer the strip though.

Still listening to anyone who wants to offer an opinion. I still like the thought of 1.6 RRs or injectors. Later

 

Forget the MAF and throttle body. The experts are right, only folks who need them should buy them. Unless you have DR's the stall is only going to hurt you by spinning like crazy.

Invest in some 1.6 RR's, I like ProMags because they less limited, but GMPP/Crane ones work fine. E-WP, alot of people dont like this or just plain dont think its worth it. I do, I gained more from the E-WP than I did from the rockers. E-WP's are an easy 10rwhp/10rwtq. ASP 23% crank replacement pulley, many folks have documented at least a tenth with this peice, dont buy crappy imitaions. Larger injectors wouldnt be necessary right now unless yours are shot. In that case I'd save money for other mods and buy some slightly used stockers. If you dont have emissions pawn your 96-97 style SLP's off on someone else. If they are single cat kind, thats not much of a problem. I'd make the move to LT's if you can. An A4 stock stall guy with basically the same mods as me runs 13.0's @106 with a 2.1 60'. Which is the reason I highlighted the ones you dont have. Mine ran a 104.4 before the pulley, E-WP, and 3.73's. I have no doubt its close or at the 106's now. I negate my 13.6 1/4 mile time since 2.4 60's arent something to be proud off Good Luck.

-Dustin-

 

The 1.6 RR's gained me .3 seconds and 2 mph in the 1/4 mile, and I didn't change the tune when I installed them. I also like the NSA Pro Magnums, with LT4 springs/retainers and locks, GM guideplates and hardened pushrods.

Total, it will run you about $400, but my car runs fantastic, and I don't think the rockers are any louder than stock, maybe just barely.

Dan

 

Get rid of the 4.10's and get your self some 3.73's.


My car with less mods than you went 13.2-13.3 @ 103-104mph consistntly, all the car had was a CAI/cut-out/3.73's.

 

PCM4Less or MadZ28 will send you a new, freshly tuned computer to your door, for a core charge, then you just send your old one back in after you see that your new one works correctly and you get almost all of the core back. I have been looking into this, but I wanna do a few more mods before I spend the $$$.