Lsx408invt

I recently purchased a 99 z28 from a member here...thanks Sam.
.
all it needed was a speed density tune and a bigger lid..went with a ftp 98 mm lid..

the car is a 408 with tfs 215 gen x heads, comp .623 .623, .247 .251 dur @ 50 111.

fast 90 ported and nick williams tb. qtp 1 3/4 headers to a 3 inch y 4 inch borlamouth back.

9inch with 4.30 gears and a tick perf stage 2 t56..

brought the car to JM Motorsports in conn. they did everything for me speed density swap and tune...... car made 520@6000 hp and 497@5000 tq car

runs awesome in town and is an animal when needed...is this a good or avg # for a 408? also anything else I can do to make more power thanks guys

blk00ss

iTrader: (66)

That's some really good numbers. You could get the intake ported or step up to a fast 102. And ditch the 1 3/4 headers and go with some quality 1 7/8" or even stepped to 2". And get a cutout before the catback.

DavidBoren

That is pretty solid.

Especially through the exhaust you have. I would absolutely upgrade to some 1.875"-to-2" stepped tube, or full 2", headers and true dual exhaust. Definitely a true dual system for a stroker.

A bigger intake would help, as well. But a ported Fast90 isn't bad.

Good numbers, though. Good to hear it drives well. Enjoy it.

Lsx408invt

silly question.....but if I change headers and exhaust would I need a retune? and is it worth it power gain wise? ...I am waiting on a mod to approve the dyno sheet pic i put up

DavidBoren

If you change the whole exhaust system, yes you should get a new tune, but it wouldn't be 100% necessary. The gains will vary from one combination to another, but you can find more than a couple instances where the switch to true duals got an additional 20+rwhp.

Lsx408invt

So prob a Kooks system? And thanks for your info

KCS

iTrader: (20)

That's pretty good considering the heads too. A 215cc head might be a little small but I'm sure it's very responsive.

Lsx408invt

That's what I was thinking...but it works real well...lots of power down low also.....hey I tried to post my dynograph said it had to b approved by a mod? Something you can do KCS?

big hammer

Post it on a hosting website like photobucket then just paste the link to it

Lsx408invt

Ok thx

speedtigger

iTrader: (16)

I bet that bad boy is a lot of fun.

Lsx408invt

It is...haven't had a chance to get any track numbers yet...but it sure is fun to drive around lol

kinglt-1

iTrader: (26)

Nice setup!!

Lsx408invt

Thanks!! I almost sold the heads and intake...but my tuner said he was even surprised with the way it made power ... After the SD swap its even more of an animal.. No traction in 2nd with 325 m/t drag radials...should be a fun launch at the track

Lsx408invt

One more question. Would a 2.5 inch hooker Blackheart exhaust work for the true dual setup?

Darth_V8r

iTrader: (4)

Yes it would. At your power level, I'd think the 3" system would be preferable. Definitely, going from a Y to an X will wake it up a bit more at the top end.

Lsx408invt

Awesome thanks for the info

SoFla01SSLookinstok

Sounds like you got a pretty bad *** z28. Nice! When I switched from the single exhaust to true duals I didn't get a retune. Just dyno pulls to see the increase. +20hp/+20tq. The car loved it.

There is definitely room for more with just bolt ons.

Lsx408invt

Hmm ok sounds like that's my next route

senicalj4579

iTrader: (41)

Yes good #s but I have to give you a heads up. I'm from CT too and I think you might want to research that performance shop. I have been there and so have others on ls1tech.