gnx7

iTrader: (28)

I love those old Studebakers!

There is an Ultraflo muffler on Summitracing that is around $80 and is one of the highest flowing and quietest mufflers out. Ditch the Flowmonster. Chambered mufflers are bad news on turbo cars.

You can also run an electric cutout!

Old Geezer

iTrader: (3)

My observations:
I'm wondering how U R getting 103* IAT's with the filter being blown full of hot air from the rad. [And, the cold side laying on the turbine housing.]
As others have commented....Timing is low for that amt of boost.
I also see you have 72# of fuel psi. Assuming you have a boost referenced reg, base fp is 58[?]. With 7# boost the fp should be 65, not 72. If this is an accurate "assumption", I'd try to lower the fp to get the base + boost accurate, and let the AFR come up to 11.7-11.8.

I'd also check back psi in the exh, B4 and after you disconnect the Blowmaster...

As for the tires. I've seen waaay too many slick blow outs on the dyno, to use them for that purpose...

pwrtrip75

iTrader: (8)

What clutch is in it? Slipping?

I had a 3.5" race flowmaster on mine and it kept building pressure and blowing the pipes apart at the joints...lol. Peice of junk. I went with the 3.5" ultraflow and it rocks.

mike13

iTrader: (27)

Are as simple as a valvetrain issue like valves not sitting on the seats, cam timing might be off. Some of these cam and crank gears it's a little confusing.

superGTO

iTrader: (2)

4000 RPM seems pretty low for a max revs. Any reason you're not going higher? And with that low of timing you're not going to see great power. I run 7psi and about 19-21* timing. No KR on pump gas and AFRs at about 11.5.

boostedsl2

i've had air filters do some crazy things in the past. while not a lsx motor, had an integra go from 360 to 410whp by removing air filter on 15 psi. had similar gains removing filters on other cars as well.

single 3" should be fine. wouldn't hurt to take a look at your exhaust pressure both before the turbo and after the turbo.

I'm not a tuner, but 11 degrees seems pretty low. rule of thumb i've always gone by is 18lbs/18 degrees on pump (usually associate that with imports), but i can't imagine thats too far off with an lsx engine.

Slowhawk

iTrader: (12)

Timing is too low and the exhaust is about as bad as you can get for a turbo setup. Fix those 2 and power will jump a ton.

MaxxMitchell

iTrader: (15)

18/18 on pump will knock the motor to death very quickly, LS motors do not like timing.

11deg/11lbs is a good tune up on 91 w/o meth. With some room to add more boost or timng.

Clutch slipping/poor valvesprings/exhaust are good things to look at first.

DrTurbo

iTrader: (3)

Agreed.

DrTurbo

iTrader: (3)

One of the most overlooked parts of a turbo setup indeed.

venom ws7

iTrader: (13)

Did you run the car for anything over 4300rpm on the dyno or street?

I agree with everyone about the timing and flowmaster but IMO something else seems wrong even with more timing & open downpipe the car will be around 400rwhp with this setup six speed trans I'd expect 470-500rwhp on 11psi maybe slightly more..

Is that 2.5 downpipe?
Awesome looking setup man good luck finding the issues.

Nitroused383

iTrader: (10)

Timing may be low but it's not going to throw off your peak tq and hp rpm increments. I've accidently made 726 rwhp with 5.5 degrees of timing at 6000 rpm. It almost looks like the cam is off a tooth.

chevellepowered

iTrader: (37)

what spark plugs you running? def do away with a muffler.. dont need one ..if have to have one .go straight thru ones.. im running 14*timing on 19lbs on a 9.9 to 1, 5.3 , ly5 pump gas with meth injection.. stock bottom end. same turbo..the magnum.. 14lbs made 550rwhp thru 4l80e.. check spark plugs. cut off muffler.. ,, bad *** build by the way..

Schraders

iTrader: (3)

Thanks for the kudos, the car should be a fun sleeper when it's sorted.

I rechecked compression today, it's 180 on every hole. How would I know if the cam is installed wrong other than pulling it all apart and looking at the dots again? Compression is good so I'm guessing the cam is in right?

I scanned for codes and got a PO332 and PO327, knock sensor bank 1 and 2 low input. This means timing is retarded under load, right? The tuner said he was doing something with the knock sensors, maybe he didn't? Or did something wrong?

I am building a cutout, not a fancy electric one just something that looks 1957 and dumps under the car. I am certain the IAC's were at 103* but I doubt they are that low with the hood closed going down the road. Thanks for all your input!

chevellepowered

iTrader: (37)

spark plugs ? what are you running?

Schraders

iTrader: (3)

TR6's at .035

mike13

iTrader: (27)

that could very much create a issue, it would be a good idea to see if the harness to the knock sensors is unplugged. Or got crushed by the intake. If your not familiar you have a seperate harness just for the knock sensors that plugs into the main harness.

awd-rwd racer

iTrader: (16)

i know the 5.3 and 5.7 are not the same motor. but i have a stock ls1 with the same mp-t76 turbo at 8 psi i make 482 rwhp and 502 torque. i think its at 13* of timing and a 3 chamber muffler

01midmetws6

iTrader: (1)

If those codes set they will pull around 6-10* of timing from the base table which would leave you with nothing. Did you get a data logged 11* of timing or was it just an assumption?

boostit5.3

iTrader: (3)

sounds like you need a diff. tuner...