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Brand new turbo very slow spool

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clang1114

10+ Year Contributor
50
0
Dec 26, 2011
Billerica, Massachusetts
I just purchased and installed a brand new FP 68hta turbo. I installed it correctly. Primed the oil system. Checked for boost leaks. Yet something just isn't right.
The car will build 6 psi by 4k rpm but after that it will spool very slow. Won't hit 20 psi until 5500 rpm.

My mods are
68hta turbo
FMIC
Fp exhaust manifold
Tial 38mm wastegate
Hall man boost controller
Dsmlink v3
Web 546/547 cams
Adjustable cam gears
A few things may be left out
Is there something I am totally overlooking? Maybe the wastegate is stuck open? I thought my tune was an issue at first but going from the evo16g to this shouldn't affect mid range spooling at all. I will attach a log tomorrow.
 
Are you 1,000,000% sure there are no boost leaks?
Yes I tested to 20 psi and pinched off the line going to my boost controller. I've had large leaks in the past and they have never done this before.

Do you think it's a possibility that this turbo spools very slow or it's defective? All the threads I've read claim it spools great.
 
Are you 1,000,000% sure there are no boost leaks?
I would definitely think that it was either a boost leak or an issue with the wastegate and or boost controller. Those things are supposed to spool pdq, something isn't right for sure. Should be seeing boost as early as 3k, and close to max by 4k with that turbo I would think.
 
What kind of BOV do you have?
I have a greddy bov. It worked fine before this turbo. I checked to see if it was leaking during a boost leak test.

Does the wastegate have the valve seat in it?
I'm not sure what you mean. It's a tial 38 wastegate mounted on the o2 housing.

Do you see your boost drop at all while at WOT?
I don't see the boost drop at all because it doesn't hit full boost until about 5k then I let off around 6500.

How would I know if my wastegate is stuck open? Would I have to take it off and put a vacuum pump on it? Also with my boost controller what could go wrong with that? It just has a spring and ball in it I think.
 
Does anyone else have ideas if the wastegate checks out fine? I will take it off today. I doubt I will find any issues considering I didn't remove it during install of this turbo. Is it possible for the turbo to have issues like this right out of the factory?
 
Is the wastegate new? Tials don't come with springs installed now.
 
No the wastegate I've had for years. I've never had boost issues with my evo16g. I ran 28 psi rock solid before I installed this turbo
 
Boost leak test? I've also had a bad cat cause this issue on a couple different cars.

No boost leaks. My exhaust is straight 3 inch to a buscher muffler. I did think i could have dropped a rag in the downpipe and got it clogged in the muffler but it would have blew out by now. It would have been one of those blue shop towels.
 
I took a log tonight of a 2nd gear pull. It seems better after playing with the boost controller. 1st gear still seems weird. Its super sluggish until 5k. Usually it will put me in my seat right away in 1st gear. It seems like I don't make full boost until 5k but it starts to somewhat pull around 4k. The boost estimate in my log is fairly accurate.
 

Attachments

  • 68hat 2nd gear pull.elg
    10.8 KB · Views: 106
Maybe the turbo just spools later than it claims to? or maybe my camshafts are dead in lower rpms?
 
Something isn't adding up. Back track all your work. You for sure it's hooked up right to the boost controller and the lines are switched.?
 
What type of intake pipe do are you running? What turbo did you upgrade from? If you upgraded from a small turbo and didn't change the turbo inlet pipe to a bigger one it will bottle neck your setup and prevent the turbo from doing its thing. I had a similar issue when I first upgraded from a small turbo to a larger one slow spool I changed the turbo inlet from the factory unit to a 4" pipe and problem was solved.
 
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