vandal0-0

iTrader: (3)

Have a 408 with a t70 turbo 16lbs of boost water-meth inj. intercooler plenty of fuel and 19deg overall timeing only made 540hp and 495 tq with a th400 tranny.Anyone have any ideas THANKS.

JD_Z28

iTrader: (19)

Its probably because of the TH400. What stall are you running?

vandal0-0

iTrader: (3)

Its a TCI 3200

THE_SUPRA

thats not a great number...but you are running a t70 on a 408... and i know the th400 is sucking alot of power from you.

Boo"SS"t

iTrader: (2)

Well, how's it feel on the streets? It might be that your t70 is just little too small for your 408. Kind of like sucking thru a tiny straw, the smaller the straw the harder it is.

vandal0-0

iTrader: (3)

The car feels fine I just expected it would make more power than it did.Billy at TRT said it had low numbers also.I was wondering if running the stock ls1 heads would cause alot of it.What size turbo do I need that will work on the STS kit.

sevanseriesta

iTrader: (34)

you are not running stock ls1 heads on a 408....that was a joke right

98Z28CobraKiller

iTrader: (17)

Stock heads, like with stock valve sizes? I know that heads aren't as important on FI cars as NA but the stock head doesn't even flow enough for the stock motor. Get a cheap set of DART 225's and let her rip.

vandal0-0

iTrader: (3)

My compression is 9.5 with stock heads dont I need like 72cc heads or if the heads flow better than there wouldnt be any detonation is that right.cause Dart heads are 64cc. I have dual springs titanium retainers and hand ported on the heads.

sevanseriesta

iTrader: (34)

Dude get some heads and you will solve most of your problems....I think the heads are choking everything

vandal0-0

iTrader: (3)

I was thinking the samething but what heads to get.I have a set of 317 do I get them cnc ported with stainless valves or just buy heads

ddnspider

iTrader: (26)

i have to ask....how did this setup come about?you have:
stock heads
a 408ci motor
a T70 turbo
is the valvetrain upgraded?
what cam?

vandal0-0

iTrader: (3)

I had the STS kit from when the car was stock so I bought a 408 short block from AMS Raceing Engines.All the pushrods, lifters,and rockers are comp cams the cam came from Speed INC. 581/581 225/225 113 LS6 intake ported throttlebody.

GrahamHill

iTrader: (6)

Thats not a lot of head or turbo for a 408. The cam probably isnt real spectacular either but with stock heads and WITHOUT the turbo it might be fine. Id try at least a 205cc head first. 113 isnt just a ton of lobe seperation either but i would concentrate on more turbo and head first.

Zombie

iTrader: (2)

I'm suprised no body has said it yet, but the turbo is WAY too small for that engine. A t76 is really small for that engine. Last time I talked to Jose he said they have a 80mm T4 flanged setup with something like a TM1 .81 a/r available. I was going to go to it but I want to work some more issued out on my car first with spooling on the line.

If you want a cheap easy setup, get some 317 6.0 heads (stock is fine). It will lower the compression more, the lower the better really, I personally like 7.8:1 - 8.5:1. If you even think about worrying about losing power from lowering the comp i'm gonna smack you, take your 408 and install it in my car. Heads help, but that is not your issue, it's the turbo. Stock heads on a 408 is not a great combo, but i'd sooner put a better matched turbo on and worry about heads later.

You want really pathetic dyno numbers? My car made 470 uncorrected on a mustang dyno at 14psi through my th400. The result is in the sig, mid 10's in a heavier than stock car. I'm eventually going to do heads on my car in the future, but that is not something I'm worried about at this time due to the cost involved (new turbos are cheaper and easier to install and make more power).

bcs

I was thinking he should get around 600 with that turbo with less than 16lbs.

Shouldn't he be able to get more out that t70?

abbaskhan

t70 wayyyyyyyyyy to small dont waste your money on any thing but a new turbo
try wrapping your exhaust and goin to a mustang dyno (rear mounts do better with the extra load on this type of dyno)
.....AFTER you get a new turbo

bcs

Didn't TRTTURBO tell you a t70 would get you over 600?

when does it spool up?

Adam98Z

Even though it's not a well matched turbo, a T70 should get over 600whp on that setup.

99Z28LS1

iTrader: (4)

i would either go with the 76mm or try something over 80 if it will fit, i know there are a lot of people having problems making anything over 80mm fit in the back of fbaodys...... but that's just what i've read and cant really prove it because i've never tried it