i dont think you where listening when people where telling you that the type of turbo kit you have will make allot of back pressure even more with an 88
He has a lot of other issues to fix before he should be even thinking about the backpressure.
He has a lot of other issues to fix before he should be even thinking about the backpressure.
Yeah, and by the time I throw the 88 on there, most of the original kit will be gone. I know there are a lot of parts currently on the car that are not the best match for the motor. The heads, turbo setup, etc. For the time being I just want to get it running good with some good supporting mods (transmission, rear, etc.) before going with a turbo that is matched for the engine. I don't think 10 PSI from the current setup is much to ask for as long as I upgrade the valve train and transmission.
So by looking at the graph, is it safe to say that would show a drive line problem?
__________________ 2001 GMC Sierra 1500 - 5.3L Vortec * Straight Pipes 2007 Pontiac G6 GTP - 3.6L DOHC VVT Stock DD 1998 Camaro Z28 - 6.0L 408cid LQ9 * Forged Rotating Assembly * TTi Street Kit w/ T76 Turbo @ 4psi * 3.73 Gears * Racetronix Fuel System * LS6 Intake * Motron 60# Injectors * 2 BAR MAP (SD Tune by Brian Reckhart) Not fast ... yet
I don't think 10 PSI from the current setup is much to ask for as long as I upgrade the valve train and transmission.
Mismatched or not, if you get it running right with this combo it will still be a fun car. I know someone local that put down 550rwhp through a TH400 and loose stall on 8 psi on a 408 and 76mm turbo. I think his compression ratio was around 11.5:1. I think they tried to up the boost and then it blew..
You still haven't told us what the compression ratio is on this motor..
And yes it can very possibly be a trans/converter issue, but like I said before its hard for anyone on here to try to guess because of all the other things going on with the car.
You mentioned that he blew the 4L60e, and used the converter from the blown trans into the new trans. That converter could have been contaminated. Have you checked the trans fluid?
Mismatched or not, if you get it running right with this combo it will still be a fun car. I know someone local that put down 550rwhp through a TH400 and loose stall on 8 psi on a 408 and 76mm turbo. I think his compression ratio was around 11.5:1. I think they tried to up the boost and then it blew..
You still haven't told us what the compression ratio is on this motor..
And yes it can very possibly be a trans/converter issue, but like I said before its hard for anyone on here to try to guess because of all the other things going on with the car.
You mentioned that he blew the 4L60e, and used the converter from the blown trans into the new trans. That converter could have been contaminated. Have you checked the trans fluid?
I wish I knew the compression ratio myself. As I said before, the shop that built the car is long gone, so I haven't been able to locate a lot of information on the motor. Not even sure my friend would know. I'll see if I can get in touch with him and see if he remembers.
I have not checked the transmission fluid. Maybe I'll check that this week and see what it looks like. Thanks again for all of your help.
- Patrick
__________________ 2001 GMC Sierra 1500 - 5.3L Vortec * Straight Pipes 2007 Pontiac G6 GTP - 3.6L DOHC VVT Stock DD 1998 Camaro Z28 - 6.0L 408cid LQ9 * Forged Rotating Assembly * TTi Street Kit w/ T76 Turbo @ 4psi * 3.73 Gears * Racetronix Fuel System * LS6 Intake * Motron 60# Injectors * 2 BAR MAP (SD Tune by Brian Reckhart) Not fast ... yet
once you get this thing figured out it seems to be a nice car...but i hope you got a good deal on it. it looks like you may be spending a lil extra dough
__________________ 02 SS FTP turbo kit retaining a/c
540/590, 11.4@128 stock drive train
95 z28, ls1 ms3, auto
94 trans am...basket case
Before you go and through parts, get good springs 1st thing then go from there. Next will be to check your transmission.
I don't thing you should have big issues with backpressure at that low boost or transmission issues. But, it's good to check your transmission and through good springs at the same time.
once you get this thing figured out it seems to be a nice car...but i hope you got a good deal on it. it looks like you may be spending a lil extra dough
I actually got the car for next to nothing.
You all think 918s would be enough, or should I go with some dual valve springs?
__________________ 2001 GMC Sierra 1500 - 5.3L Vortec * Straight Pipes 2007 Pontiac G6 GTP - 3.6L DOHC VVT Stock DD 1998 Camaro Z28 - 6.0L 408cid LQ9 * Forged Rotating Assembly * TTi Street Kit w/ T76 Turbo @ 4psi * 3.73 Gears * Racetronix Fuel System * LS6 Intake * Motron 60# Injectors * 2 BAR MAP (SD Tune by Brian Reckhart) Not fast ... yet
At 2 psi, the poor thing hasnt even made it back to NA power level. See my sig It took 2 psi Just to get back to what my motor made NA. Thats all, it needs more boost
You guys really think that a turbine housing flows REALLY well? LOL! It doesnt! It works GREAT when it actually puts a positive pressure in the intake Thats the point.
__________________ Louis@LGMotorsports.com 972-429-1963
Cyber Grey 09 Z06 Stock for now....
01 SS A4
520/520 SAE Dynojet 2 psi, 402 CID LS3|G7x1 cam| 11.0:1 SCR|PT88| 4" down pipe|Stock catback just getting started www.LGMotorsports.com www.LGMRacing.com
I see your point...one thing that still baffles me is that I normally see ~5psi on the street in 2nd gear. I have verified this with my tuner who looked at my logs and said my MAP would peak at 140kPa in second gear. We never really took it into 3rd because by that time I'm going a little fast for anything on the street. Got to be something with the drive line (as well as the other things mentioned) that is causing the strange HP/Torque curves.
I should of had him do some data logging while it was on the dyno. That would of really helped to see what was going on.
__________________ 2001 GMC Sierra 1500 - 5.3L Vortec * Straight Pipes 2007 Pontiac G6 GTP - 3.6L DOHC VVT Stock DD 1998 Camaro Z28 - 6.0L 408cid LQ9 * Forged Rotating Assembly * TTi Street Kit w/ T76 Turbo @ 4psi * 3.73 Gears * Racetronix Fuel System * LS6 Intake * Motron 60# Injectors * 2 BAR MAP (SD Tune by Brian Reckhart) Not fast ... yet
1. Check for fouled spark plugs.
2. Set gap low (try 0.025") then move up until it starts blowing out under boost.
3. Replace valve springs with Patroit Dual Xtreme.
4. Monitor Backpressure or Get Turbo Specs (eg.A/R).
5. Look at drive line.
__________________ Z28 + CP 402 LS2 (9.5:1 + Wiseco Pistons + Howards Rods + Carrillo Crank + Hellfire Rings) + Patriot Heads + ATI HB + Poly Mounts + Megasquirt (Meth Injection, Launch Control, Flat Shift, Knock) + LC1 WB02 + Stage V T56 + Hurst Shifter + PST 3.5" DS + Moser 9" 3.25 + Dual 3" w/ Super 44's + Twin Turbo MPT70 + Twin Tial 38mm WG + FMIC + Tial 50mm BOV + Edelbrock TA,LCA,PHR + BMR SFC,STB + Tokico Shocks + Spec V + Twin Walbro 255HP In Tank w/-8 feed + PP Rails + PP FPR + 96lb inj's + 315's in Back