So I purchased this 2002 Z28 A4 back in 2009 with 10,000mi. The car has some mods:

-SLP lid
-Ported TB
-LS6 intake(came stock in 01-02)
-1.85 Slp Rockers with 918 springs.
-Kooks 1 7/8 LT's
-Kooks True Duals
-FTI 3800 stall with trans cooler
-Transgo Shift kit
-Motive 3:73 with T2R diff and TA cover.
-Umi tq arm, bmr sfc, kyb agx shocks.
-Toyo 315/35/17 DR's

I have been contemplating my next set of mods and I am really torn on which way to go. Budget is not a huge issue at the moment but I want to do things right. I have been around here for quite some time so I have a general idea but some opinions would be great!

I do not daily drive the car. It only has 17,000 miles on it currently, so I have put 7k on it in the last 5yrs. Good drive-ability is my main concern. Here are my options:

-TSP 427(put the 346 in my yukon)

-TFS as cast 220's from vengeance with a VRX3.(remove SLP rockers and use the stockers with Trunion upgrade)

-TFS 220's with Comp XR277 low lift(224/228) designed for high ratio rockers and keep my SLP 1.85's being they already have upgraded trunions.

-AI High CR 219cc 241's with XR277

-AI 219cc with their 226/230

I have also considered forced induction:

-Brutespeed D1SC kit w/ Front Mount IC. 7000.00

-Hawks Third Gen TVS 2300 kit. 7500.00( notching the cowl is kind of a deal breaker)

Not sure if I want to deal with the headache of forced induction. I had a P1SC kit on a pretty much stock 96 Z28 M6 car back in 2003. It made 425whp on 7lbs but the kit was junk. I know forced induction has come along way since those days.


Thanks for reading.

 

Bump...anybody?

 

That 427 sounds real nice

 

I guess it just really depends on long term goals for the car. If you just want some power and long term reliability, i would think heads and a cam would be a good route, or if you want to make a 9sec race car out of it start building in that direction lol

 

Not really wanting to make it a race car. The car is too nice for that...literally still has the new car smell(I know I know it is just a F-body). I might buy a roller to make a track car. I really just want something with more power yet reliable. This will be a 100% street car. The car does run great now but lets face it bolt-on LS1 power is sooo 10yrs ago lol.

I am really thinking about the 427. My Yukon has 193,000mi and I plan on keeping it for another 100k since it is in really good shape and the price of new ones are retarded

 

I'd do the D1 Procharger. It'll make more power than the 427 and be more streetable.

I think I'd do the TFS 220s with the D1 and maybe the Brutespeed supercharger cam. You can hit 600rwhp pretty easily with that combo and more if you want to turn up the boost. The issue is the transmission.

With the D1 or the 427, I would think you need to budget for at least an FLT Level 4 or equivalent. The FTI 3800 probably isn't going to work as well with the boost so you'd need to get it restalled as a tighter converter.

The TFS 220s and something like a VRX4 would be my choice and it would work with the stall you have and the stock trans (but it'll be on borrowed time if you do WOT blasts).

Point is, I think an upgrade of the trans is first in order and then maybe looking at the H/C/D1 or 427.

Also - the Kooks TDs are going to be loud as hell with a cam or the 427.

 

Thanks for the Input Jake. I did forget to mention the FTI 3800 was spec'd for a power adder, so it is a bit tighter.

 

Then yeah. You could do the D1 now, keep your RPMs below 6k and ride on the stock trans for a while. The D1 will be the big dollar item. When you want more, add some heads/cam and a built trans and let her rip at 6600-6700 and really make some power with the D1. But you don't really need the heads. Just the cam and a smaller pulley/Aster bracket would be good.

I believe the fuel system is good to around 700rwhp with a BAP, so you might want to budget for a Racetronix Pump, KB BAP, and some 60lbs injectors. That would be good for what you can do on the stock motor. Though I wouldn't push much beyond 600 on the stock LS1. LS2/3 I'd feel okay with 650 and the right tune.

Beyond that and you want an F1A, dual fuel pumps, and 80lbs or more injectors. But once you start climing into the 800+rwhp land, a 4L80E would be my choice on the trans.

 

I am not looking for big hp.. I would be happy with 500-550whp. I think you are convincing me to get back into the procharger game. I have spent several hours reading up on 427 builds and I am not sure the LS3 427 route is the way to go being the 4.125 stroke seems to be frowned upon. the LS7 seems to be the way but cost a bit more coin with good heads. However most of the threads I found were older so maybe things have changed. I also do not like the idea of the car getting much louder. It sounds perfect righ now other then the stockish idle.

 

Ok so just wanted to update my thread. After a month of going back and fourth between going with a ProCharger, 427, or a simple H/C package, I think I have settled on the latter. Mainly because I just want this car to be a fun weekend toy that is enjoyable to drive. I am considering purchasing a Roller or another car for track duty in the future. Just spending some time in the Classified section made me realize it is so much cheaper to buy a car already done for less then the price it would cost to mod mine to where I would want it to be for a track setup.

Here is the the setup I am considering:

Trick Flow TFS-220's from Tick performance hand finished by TEA. 63cc chambers with powder metal guides.

Cometic .040 gaskets for 11:1 compression

PAC dual Springs with Ti retainers

Tick 229/231 .62x .62x 113+3 camshaft

Stock rockers with upgraded trunions

Hardened push rods

Ported LS6 pump

New timing chain, most likely a LS2 or Cloyes.

Considering a Fast 92 and selling my LS6.


Any thoughts on this setup? Is there any other combinations out there that "may" work better? I am looking to make the most power I can without sacrificing drive-ability. Not interested in running a huge cam, I would rather put the money in the heads. So If that means if there is a better head option out there then feel free to post it.

Also what are some opinions on running a quality beehive opposed to a dual spring. I know the safety factor of running a dual, but won't the beehive free up some power and easier on the valvetrain?


Thanks.

PS

I still have not ruled out a procharger if I can get a decent buy on a used D1SC kit. I just miss the sound I had from my previous car, which is mainly why I think a nice H/C package would be sweet.

 

The beehive spring will only free up power if it is able to control the valve throughout the rpm range. With .62X lift I would just use a quality dual spring.

 

ok thanks for the advice!

 

well just figured I would update.

I decided to pull the trigger on a tried and true XE lobe 224/228 112 cam. 2 degrees of overlap and easily controlled with a good beehive. I know some will say I should of went bigger, but I just wanted a nice driving easy to tune cam.(I am doing my own tuning)

I also purchased:

GM HD timing chain(12646386)

GM High volume pump (17801830)

GM bolt and gasket kit

Chromoly PR's

Already have comp 918 springs


Going to hold off on heads for now. Still undecided if I want to do the TF 220's or AI HC 218CC 241's.

 

The cheapest power you can make is increasing compression. Increase the compression by using a pop up piston or smaller head chambers.

"big" cams with a lot of overlap will lower dynamic compression at lower rpm's, but tend to increase it at upper rpm's.

NEVER use the head gasket to adjust compression. Head gasket thickness should be determined by proper quench.

The second best way to increase power is by adding cubes. It's only second (IMO) because of cost. With big cubes, you can use mild compression ratio's, close quench, and relatively mild cams to make big torque. That makes for a fun and easy to drive engine, that won't break the bank at the pumps.

There's no replacement for displacement. You can't beat cubes.

 

Trust me I know...my dad is a die hard big block man. We are kicking the idea of going halves and building another car with a big cube LSx motor. I have been looking at some nice rollers that are partially done. Part of the reason why my plans somewhat changed for this car. I mentioned to him I was either going to go with a D1 or possibly a big cube motor and he suggested doing a mild h/c setup on this car and "lets build something nasty" to take to the track.

Anyway that is why I am still undecided about the heads. I do want to get the compression up and for my goals with this car, the high compression AI heads will probably be good enough. But then again I have seen some TF 220 mild cam builds make some impressive power.

 

Update! I was offered a fresh set of 61cc TEA Stage 1 243's (Z06 valves) for a reasonable price from a forum member. I can get these for significantly less money then the TF 220's.

Thoughts?

 

Do it.

 

Ok you convinced me

 

Question:

What head gasket should I go with for a stock valve 61cc head? I was told that a stock mls gasket and 61cc head should yield 11:1 compression and maintain plenty of PTV. However I am curious if I can get away with a .40 gasket and a 224/228 112 cam for even more compression?

 

Just ordered a Black Fast 92 with Nick Williams 92mm TB.