ScreaminRedZ

iTrader: (3)

Just wanted to share the progress my brother has made with his 1994 Z28. The car is an A4 and came with 2.73 gears. I owned the car before him and the only mod at the time was the ZR1 replica wheels.



In stock form the car made 230 rwhp and 273 rwtq (almost exactly the same as my previous A4 LT1). The car ran 14.3 @ 98 mph.



Next up we put a K&N CAI, 1LE elbow, airfoil, Magnaflow catback, 3.42 gears, alunimum driveshaft, electric waterpump, underdrive pulley, and Nitto drag radials.

The car ran pretty consistent 13.6-13.7 @ 100 mph.

We put the car on the dyno, but it was breaking up. On the street we couldn't tell except for an occasional stumble. The car put down 250 rwhp and 273 rwtq, but clearly wasn't running right.

We replaced the plugs and wires and it seemed to run better so we put it back on the dyno and it had picked up to 272 rwhp and 303 rwtq.

Here's the graph before and after the new plugs and wires:



Next up, we installed 1.6 Scorpion roller rockers and upgraded the valvesprings. We didn't dyno it after that change alone, but he ran 13.53 @ 102 mph the one day he got it up to the track.

Just last week he installed a set of Pace Setter ceramic coated shorty headers and y-pipe, with cat-delete. We got it on the dyno this morning and the rockers and headers together were worth 20 rwhp and 18 rwtq:



He's hopping to run 13.2-13.3 @ 104ish as it sits, which I think is a reasonable goal.

Not the fastest LT1 out there, but it's coming along nicely.

Next he plans on getting it tuned (a/f is a bit iffy in the mid range) and maybe trying a bigger throttle body. Also in the works are a nitrous kit, stall converter, and cam.

rich5368

iTrader: (2)

Sounds like it's coming along. I think he's losing some with the shorties and would definately go long tubes if he decides to do heads/cam. Bolt on only close to 300 is pretty respectable though. Stay with it and by all means as gregrob would say SPRAY IT!!!

ScreaminRedZ

iTrader: (3)

The car would have gotten long tubes, except it has to pass emissions by going on the rollers, so it needs a functional cat (he can swap his off road pipe for a cat in about 20 minutes). Long tube setups with the cat after the Y-pipe seem to have trouble passing. I think that places the cat too far back.

Down the road the car will get long tubes, as he can eventually get the Kooks catted headers, or worst case scenario the car will be exempt in 2019. For now these will have to get him by.

coolmanvette75

iTrader: (2)

My bolt on car put down 293/338 and ran 12.9. Your goals seem to certainly be within reach. Good luck!

SoxXpupPeT

iTrader: (34)

Thats one of the best bolt on/ power list there is! Good goals i must say. How come you didnt go with Long tube headers?

guppymech

iTrader: (7)

I've followed the same path your brother has with very similar results at the track. I'll say to date my best mod has been adding the much maligned Hotcam. No track time yet here in Chi-town but the cam change gave a great SOTP improvement. Have your Bro move the cam change to the top of the list!

Zlow28

iTrader: (11)

very nice, nice to see you document everything down.

blakez28

iTrader: (6)

Love these threads. Keep documenting when he adds additional mods.

ScreaminRedZ

iTrader: (3)

Thanks for the comments and compliments, guys! I was going to follow the exact same path he's taken if I had kept the car, so this has been just as fun for me as for him

Emissions, unfortunately. It would be nice to see the different between the shorties and LT's down the road. With the car making more power from future mods I'm sure the gain would be quite nice.

I'm personally a big fan of the Hotcam in a daily driver type setup, but he's already said he wants to go with a bigger cam as he doesn't drive it everyday. Because of that he needs the stall first. He'll probably get a nitrous kit next up, because there are some decently fast cars around here and that would let the LT1 suprise a lot of them. They never see it coming

lt1-xjs

Hopefully he will hit his goal, then it's time for the "Yank". I made it to 299 rwhp / 330 tq with the 1.6's. He should easily break 12's after the converter.

ScreaminRedZ

iTrader: (3)

That'd be mint. I told him he'd probably see 12's after a stall.

bowtienut

iTrader: (1)

Very nice progress!
Is all of this wth the stock tune? I didn't see any mention of dyno tuning it.
If it's still stock, there's a chunk of hp on the table still.
Regarding the headers: I'm not familiar with the PaceSetters, but some shorties do very well on stock cam engines. There's not enough valve overlap to see much of the scavenging effect that longtubes provide. I had SLP shorties on my Impala with the bolt-on motor and put down 309 STD rwhp with the dyno tune. I later went with Tri-Y's; didn't dyno them, but track performance didn't change noticeably from the SLP's.

bowtienut

iTrader: (1)

Probably? With a Yank SS3600 and a good hook, he'll be looking at low to mid 12's

ZFreie

My car is juts like the OPs lol, hes doing all the work and research for me haha all I'm missing is the valve train...

I know my #s arnt that good, but, heck, even close is fine by me!

ScreaminRedZ

iTrader: (3)

Still on the stock tune. What is people's experience with LT1edit? He's looking into either getting that and having a local tuner dyno tune it, or going with a PCMforless mail order.

Even better!

pillarpod

way to keep track of it all

bowtienut

iTrader: (1)

I ran with a PCMforLess mail order tune for a couple of years. It was very close to optimum. At the dyno tune, (PCMforLess did it also), he was able to squeeze out only 3 or 4 more hp.
I'd guess you're leaving about 15 hp on the table running the stock tune. It's probably on the rich side and very conservative timing; at least mine was. His mail order picked me up .15 sec and 1.5 mph.
With all that said, if you're close to a dyno tuner, do that. Skip the middle step and the uncertainty. I've never used LT1 Edit. I use TunerCat - because it's Cheap!

95mysticta

iTrader: (4)

You can still run long tubes with dual cats just make them closer to the collectors and you will pass emissions no prob just dont skimp on the cats. I guess for simplicity the shorties work best with only have to use one cat for making it pass. You could prob make up some cheap slip in/out cat deletes to put in place after you have to test it. Definetly leaving some power on the table with shorties.

muddyjimmy

iTrader: (15)

Good numbers and documentation for a bolt-on LT1. I need to see what numbers my bolt-on car does. So, are we going to see this car in the Street Stock class at the LTx Shootout?

ScreaminRedZ

iTrader: (3)

It's not my car and he had to work within his budget while remaining emissions compliant. Just an easy place to find horsepower in the future.

I wouldn't bet on it just because it's hard enough getting up to our local track, 2 hours away. That said, I do love reading about the LTX shootouts