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Dissapointing Dyno Numbers. Any Ideas?

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Old 06-27-2012 | 03:09 AM
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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 06-27-2012 | 07:38 AM
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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...

Last edited by Old Geezer; 06-27-2012 at 07:44 AM.
Old 06-27-2012 | 09:22 AM
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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.
Old 06-27-2012 | 09:39 AM
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Originally Posted by skinnies
Do a compression check, I got a brand new EPP cam that was ground wrong once, didn't dyno, but the car was obviously a huge turd, pulled compression check and numbers were horrible. Threw in my old cam and bam, compression check looked good and went out on the street and pulled good again.
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.
Old 06-27-2012 | 12:13 PM
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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.
Old 06-27-2012 | 01:30 PM
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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.
Old 06-27-2012 | 01:46 PM
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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.
Old 06-27-2012 | 01:51 PM
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Originally Posted by boostedsl2
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.
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.
Old 06-27-2012 | 01:53 PM
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Originally Posted by Slowhawk
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.
Agreed.
Old 06-27-2012 | 01:53 PM
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Originally Posted by 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.
One of the most overlooked parts of a turbo setup indeed.
Old 06-27-2012 | 03:33 PM
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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.
Old 06-27-2012 | 03:58 PM
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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.
Old 06-27-2012 | 08:23 PM
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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..
Old 06-27-2012 | 09:49 PM
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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!
Old 06-28-2012 | 11:35 AM
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spark plugs ? what are you running?
Old 06-28-2012 | 11:38 AM
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Originally Posted by chevellepowered
spark plugs ? what are you running?
TR6's at .035
Old 06-28-2012 | 11:45 AM
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Originally Posted by Schraders
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!
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.
Old 06-28-2012 | 07:02 PM
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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

Last edited by awd-rwd racer; 06-28-2012 at 10:07 PM.
Old 06-28-2012 | 08:18 PM
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Originally Posted by Schraders
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!
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?
Old 06-28-2012 | 10:30 PM
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sounds like you need a diff. tuner...


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