Stage 1 Dyno disaster

N

norbs

Classic fast, XFI, SPortsman & MS3 programming
Joined
May 25, 2001
I have dyno'd my car and have come up with some disasterous dyno numbers.

330hp@16 psi boost at 12.0 a/f
217 hp@16psi 11.0 a/f

Hp falls off dramatically at 5400 rpm. The headers are glowing orange, not red. The timing is about 24-25 degrees on 94 octane fuel. The timing is verified within one degree of the dfi. This is the combo

stage 1 block
224 billet roller cam
TA alum SI heads ported
TA headers
71 GTS turbo
4 bolt .81 a/r
hogan sheet metal intake
120 lb ijectors
gen7 dfi
msd distributor.
cotton front mount.
3.5" custom dp

Any suggestions where to start?
 
fuel pump? trans slipping? o2 sensor wrong? got data log numbers? or can send the datalog?
 
Start with the recluctor ring on the balancer. You have said that you have a feeling the keyway is cut in the wrong position on the other board. Verify that by putting #1 cyl to TDC and take off the balancer. Look where the keyway is located by using a stock crank. If its off, verify how far out it is and take off the reluctor ring on your BHJ balancer and do the math as where the ring needs to be in order to fire like the stock setup would. Might also have to pull your front cover and check your timing and make sure you did everything correctly. This definately sound like a timming probelm.
 
A brain transplant? Some things never change.
 
norbs said:
I have dyno'd my car and have come up with some disasterous dyno numbers.

330hp@16 psi boost at 12.0 a/f
217 hp@16psi 11.0 a/f

Hp falls off dramatically at 5400 rpm. The headers are glowing orange, not red. The timing is about 24-25 degrees on 94 octane fuel. The timing is verified within one degree of the dfi. This is the combo

stage 1 block
224 billet roller cam
TA alum SI heads ported
TA headers
71 GTS turbo
4 bolt .81 a/r
hogan sheet metal intake
120 lb ijectors
gen7 dfi
msd distributor.
cotton front mount.
3.5" custom dp

Any suggestions where to start?
Click to expand...


Distributor or Cam Timing...
My car did that when my engine builder put my cam on the wrong key way.
Since your cam has been in for a while I would verify your timing and make sure the distributor is synced and working correctly.
 
Mike,I run an external crank trigger, so the reluctor ring is not used. I can move the pickup anywhere i want +/- 10 degrees. But if i had used the reluctor setup you had a good idea to check it. I'm weldiing up some mounting system to get the degree wheel on in the car. So i will know soon if the keyway is wrong for sure. The motor idles fine, turbo spools up , no lack of fuel pressure, a/f is bang on compared to the dyno, no knock. I lost the cam card, when assembling the motor, but found it now. But how much impact would the cam timing being a few degrees off really have? At 16 psi i should be close to 450-500 hp i estimate with the given parts? Could the motor run so good and be out so far?
 
norbs said:
Mike,I run an external crank trigger, so the reluctor ring is not used. I can move the pickup anywhere i want +/- 10 degrees. But if i had used the reluctor setup you had a good idea to check it. I'm weldiing up some mounting system to get the degree wheel on in the car. So i will know soon if the keyway is wrong for sure. The motor idles fine, turbo spools up , no lack of fuel pressure, a/f is bang on compared to the dyno, no knock. I lost the cam card, when assembling the motor, but found it now. But how much impact would the cam timing being a few degrees off really have? At 16 psi i should be close to 450-500 hp i estimate with the given parts? Could the motor run so good and be out so far?
Click to expand...

Norbs sorry about the first post, I did not see all the specifics.
I had a Rollmaster timing chain with multiple key ways.
http://www.romac.com.au/pdf/Factory Timing Marks Books.pdf
I ended up having piston to valve issues. The piston won...
 
Did you go back to 12.0:1 after the 11:0 and repeat with 330hp? Sounds like a cam timing or ignition timing problem. Report back after degreeing.
 
It wont be going back to the dyno until spring, but no i didnt retry it after those pulls, from those results i knew something is majorly wrong. I'll report on the cam timing as soon as i get the results.
 
It appears the cam is in at 6 degrees retarded from the real tdc mark using the piston stop to find tdc. The balancer mark is out 2 degrees also. Could this create such a hp loss?
 
That would do it alright. I don't know what keeps you sane. Your motor has been in and out probably 20 times since this project started and your tranny about another 15 to 20 times. If that was me the car would be gone or set on fire. I was contemplating putting one together myself as a project, now I am going to stick to what I do best, and thats putting ink on paper. DLS here I come.:) All the best Norbs, I hope the worst is behind you.
 
If anyone can figure it out I'd figure you would find it. Just step back for a while and try another angle at it. You will get it.

Steve
 
Try not just putting the cam in straight up but advanced a couple degrees. I tried that with some pretty good results. (think no spool lag)
 
I have the car almost together cranking compression has changed from about 125 to 150 psi now. The cam is in now one degree advanced, but as you have pointed out i should have maybe advanced it 4 degrees?
 
Norbs, I noticed your sig. Don't be too hard on yourself, you will get it straight. Hang in there you will have your day. :smile:
 
Norbs check to be sure you have advance. KevinB had this same problem. He had no esc signal so timing stayed at 0. Check the advance with timing light without the fixed timing set in your DFI. No ESC and you will have 0 +or- 1deg. Fixed problem car went over 600 next pull.
 
norbs said:
I have the car almost together cranking compression has changed from about 125 to 150 psi now. The cam is in now one degree advanced, but as you have pointed out i should have maybe advanced it 4 degrees?
Click to expand...

Good luck buddy, it sounds like you are getting there.
 
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