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94 cobra first dyno results

2K views 22 replies 11 participants last post by  kbscobravert 
#1 ·
All drama aside, ie with on3 and the fuel injector issue, the car ran strong. The only mod to the engine is an F cam ( I know I would have been fine with my stock cam but gotta have me some lope!!!)

At 9lbs the car made 393hp and 452 ft/lbs of torque. Tuner said he could of squeezed out more but I decided to up the boost at this point. I had the red spring in the gate( mine came with 2) which gave me 6 lbs and then I adjusted by hallman boost controller to get the 9lbs. So I simply turned the boost controller up and we did another pull. The boost jumped up to 10.3 lbs at around 3200 then slowly dropped off as the rpms got higher. It was only showing 7 lbs of boost by the end of the pull at around 5500 rpms. So by turning the controller up, I in turn made less horsepower?? Can someone please explain what could be going wrong.

After that pull, I decided to put the blue spring in after seeing some people were seeing 10lbs with it. It made 11.5 lbs and he cut the dyno off at 3800 rpms. The car made 384hp and 528ft/lb of torque by that point. Didnt want to get greedy and we ran outta time so I left with the 9lb tune.

9lbs:


And the short 11lb pull:
 
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Discussion starter · #4 ·
It would seem to me you have an issue with the wastegate if you are using an on3 go with a tial much better piece.
I realize it isnt a quality wastegate such as tial, but you dont think it may have been boost controller related? It held at 9lbs throughout, just not when I turned the boost controller up more. I will eventually upgrade the components of my kit, I was just curious as to why this happened and if anyone has experienced this.
 
Discussion starter · #8 ·
I would double check to make sure you have the boost controller installed properly before blaming the wg. I've been running the same wg for 2 years with no problem. I'm running the smallest spring and MS electronic boost controller.

Did you tap the turbo compressor housing and ran a vac line from the compressor to the boost controller?
I have it hooked up according to the hallman directions. The boost changes as I adjust it. Just thought it was weird how it dropped off. I didnt tap the turbo compressor housing tho. I had a bung welded in after the intercooler and maf and before the throttle body.
 
Discussion starter · #12 ·
Nice! Lee is a good tuner, get that boost control issue figured out and get back on the dyno.
Yea, Lee is a top notch guy. He went out of his way multiple times to help me after having issues unrelated to the turbo kit itself. I will be back for sure. I still have the stock rear end and I am a little undecided on going 3.27 or 3.55s. I need to work on getting some traction tho. 1st and 2nd are nothing but spinning when the boost hits.
 
Discussion starter · #13 ·
Drill and tap the turbo compressor housing above where the discharge tubing connects. I am pretty sure that putting it after the bov will cause problems.
Gotcha. I will definitely look until this. It holds boost steady now so I might leave as is until Im ready to turn it up. Which may not be very long. Its very addicting
 
Discussion starter · #17 ·
What part of Indiana are you from? I live in Jeffersonville. I also took my car to Lee. He is a great guy and help me out a lot also! I will be back to see him when I turbo my car
Im from around the Evansville area. Hopefully, I can fix some of my issues and turn the boost up a bit more and be back by the fall.
 
Discussion starter · #18 ·
I have a homemade boost haulman type controller and I also have boost bleeding off as you did, Can't seem to figure it out myself. I'm tapped at the compressor housing so, since your not tapped at comp. and we have the same problem. Don't think that will fix the bleed off for you. If you fix the problem please pm me and I'll do the same if I come up with a fix. And great numbers, no wonder I'm surprising people with my stock 351 on 12ish lbs. LOL
Will do. I wonder if I would have been ok with the 11.5 lbs. I have arp head studs and fel pro 9333's. Maybe it would have held and the bc is at fault. Just curious as to what would have happened if we finished the pull, didnt want to get greedy and blow a head gasket.
 
Discussion starter · #19 ·
Have you done a boost test on your piping? A buddy just had the same issue...at higher boost levels, a leak was letting out the added pressure limiting how high it would go.
Hmmm.. no I havent. How do you test it? Its just weird that it held steady at 9lbs but when I turned the bc up, it went all the way down to 7lbs.
 
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