I am in dire need of en ecu tune due to just installing my new 350, it doesn't have the appropriate power I built it for...help?


Posted from Thirdgen.org App for Android

 

Don't know anyone doing tuning on TBI only TPI.
What kind of power are you expecting from your TBI?

 

well the way I built it I was told I should be close to 320 with stock exh manifolds, all emissions crap and tbi intake... it's a 9.5 comp with 441heads slightly ported, z28 race springs, xe268 cam, etc

 

Well this is my motor with heavily ported and modified TPI intake Dyno Don headers and his custom dual cat 3" cat-back exhaust making ~350 RWHP and 370 RWTQ so maybe you're a little optimistic.

The Short Block:
4-bolt main roller Vortec "880 casting #
TRW forged pistons .030 over (357cu. in.)
ZZ4 powdered metal rods
Cast crank offset ground
.020 deck height
Compression 10.6/1

The Heads:
Edelbrock E-TEC 200's 90989 #
Fully ported by "Jerrywho"
Flow #'s 270/218 w/o pipe
Milled to 60 CC's
Dual springs good to .600 lift 135/360 pressure #'s
With 10 degree locks.

Camshaft:
Crower cam 225/232 114 LSA (installed on 110* intake centerline)
Lift .585 intake .550 Exhaust
Roller rockers 1.65 intake/ 1.5 Exhaust
Cloyes double roller chain
Melling 55A oil pump
Manley head bolts and washers
Genuine Chevrolet valve covers

Not sure what "ultimate TBI mod" is but the stock TBI is not sufficient to flow enough air for the HP your expecting. The stock exhaust on these cars are horribly restrictive, also the stock Y=pipe is really a T-pipe causing some blow-back at the junction.

 

other than the .030 over bore and your larger heads/ compression, we have quite similar engine builds...

 

Sorry but the only similarities are probably the block. Heads, intake, exhaust will make a huge difference.

 

true, I just adjusted the timing and the throttle response is much better, then I did the fuel pressure regulator adjustment and that helped too, I guess it's time to put gas in and drive a bit too see how it looks being out of park... it seems to idle and respond best to +10° is that normal or too much?

 

raped ape! I'm all smiles for now, I don't really care what numbers I'm making because even without an actual tune, it's running great on the road...


Posted from Thirdgen.org App for Android

 

Turbo City in Orange is about the only 'local' facility that can actually tune modded TBI cars. He's definitely not cheap, but he'll get you dialed in

http://www.turbocity.com/

 

Tom is really not touching anything anymore. they have gone into the Motorcycle aftermarket product business mostly now and have pretty much dropped all to the old TBI stuff they were making and doing.

I always hear how TBI is so restrictive, it must be the intake manifolds on the 3rd gen motors that are restrictive, not the actuall TBI unit. Why, Becasue when I run my TBI on both my single plane MPFI manifold(with the port injectors passive), and my dual plane manifold. I pick up about 60hp over running the dualplane aftermarket Edelbrock TBI manifold. I also am getting the same exact power whether I run the TBI injectors (2) or I run the Multiport(8) injectors both with the same singleplane manifold. The MPFI system runs dirty and will not pass smog though- even though it was CARB E.O. certified when I bought it 10 years ago. It used to passs prior to the state #'s tightening down- it has always blown the same #'s when I compared the old tests to the new more restrictive test #'s.

TBI makes great power it you put it on the right intake manifold.

It has however passed smog test witht he MPFI injectors unplugged and passive -with the TBI injectors back on top spiced back into the harness- yes for some reason I visually got away with this.

This vehicle has never been on a dyno, but it has onboard telemetry to directly compare setups. With the singleplane MFPI (8) injectors it runs a 13.6, with the singleplane with TBI (2 injectors)up top in runs a 13.7, and with the dualplane and TBI it runs a 14.8-9 on a 5000lb vehicle. Without touching anything else.

 

yea tbi unit itself can support power assuming you do ultimate tbi mod can support around 400hp IIRC

intake will hold you back like stated above no matter what you do to it on stock intake

stock exhuast is very restrictive is that 320 flywheel ?????

not local but will make a chip for you
http://www.tbichips.com/

stock intake and exhuast just going to hold you back double bottle neck and wasting $$$ unless you plan to upgrade
"just cause it feels fast and sounds loud doesnt equate to going fast"

is this the same engine that you where building in the other thread ?