I recently installed a SP61 bolt on turbo and I know the waste gate spring is set at 14 psi. When I went for a drive it was boosting a maximum of only 3psi boost. Then I hooked up the electronic boost controller and set the boost to 14. It boost right but it took a long time to spool like 5k rpm. I doubt it is a boost leak since. I contacted SP racing and they told me there is a little bit of pretention in the wastegate actuator and I have to remove the c-clip and turn the adjusting nut since the wastegate might be open a little bit. I did this but still spools very late. I can even adjust the boost controller to hit lower boost like 10 psi but again takes a long time to spool . Has anyone had this issue? removing the c-clip on the wastegate actuator with the turbo installed is a pain.
SP61 boost issues
- Thread starter V8hntr
- Start date
either
A. wastegate is stuck open/ not adjusted correctly (most likely)
B. bad exhaust leak
C. boost leak
A. wastegate is stuck open/ not adjusted correctly (most likely)
B. bad exhaust leak
C. boost leak
Id drop the dp and test the wastegate while making sure it closes fully. I hit full boost by 3800rpms or so.
Depends on how much boost your running though, keep that in mind. 6psi spools much faster than 15 or 20...
Also depends on gear ratio and what gear you're in.
You'll see boost at lower RPM in 5th than you will in 1st...
You'll see boost at lower RPM in 5th than you will in 1st...
Poodles;1217488 said:
I am running 14psi and in 3rd gear it buildsup gradually from 3-4 krpm and around 4500 the rear breaks loose. It is a huge difference from my upgraded CT26 60 trip which came to full boil by 3000 or so. I will try to readjust the wastegate by removing the actuator rod c-clip and see if the flap has any slack in it and get back to you guys.
what was the issue and how did you fix the stutter?
your sad build up of boost sounds like the wastegate is staying open... wait until you get full boost at 36-3800 rpms, it hits like a train!
I had some boost creep with the 14 psi spring. I had to port the wastegate port and the leading edge and it seems to have taken care of it. 14 psi at 3600 rpms and 17-18 psi by 5000 rpms in 4th.... really really sucked as i couldnt turn the boost up at all with out hitting fc.
your sad build up of boost sounds like the wastegate is staying open... wait until you get full boost at 36-3800 rpms, it hits like a train!
I had some boost creep with the 14 psi spring. I had to port the wastegate port and the leading edge and it seems to have taken care of it. 14 psi at 3600 rpms and 17-18 psi by 5000 rpms in 4th.... really really sucked as i couldnt turn the boost up at all with out hitting fc.
Should be able to hit 14-15psi at abut 3300 rpm's in 4th gear. Or about 3800-4000 rpms in second gear. That's with the EVC hooked up. If it's boosting much slower than that, you have a problem. I never had to port anything on my SP61GT, although I did have to put a bend in the actuator arm so it would push straight; That was actually causing overboost with mine.
Make sure you have no rips in your vacuum lines. That got me one time.
Make sure you have no rips in your vacuum lines. That got me one time.
The stutter problem was a bad Maf sensor but that's fixed. The boost issues is not fixed yet. On the dyno even when the boost controller set at 1.3 bars (18.8) psi , I don't get more than 12 psi. It spikes to 16 by 3800 rpm but then goes to 12 as the rpm's increase. I dropped the downpipe and the flapper is ok, no rust or anything. The wastegate actuator works great too. I tested it with compressed iar and it opens and closes just fine.
grimreaper;1247899 said:
Be sure to smooth both the wastegate opening and flapper along the edges if you decide to port. I have an issue with my Turbonetics Hi-Fi's (should be same hotside as yours) flapper jamming against the wastegate opening when it closes due to a shit port job by the previous owner. That;s sure to give boost lag since it's held open a good 2-3mm.
grimreaper;1247899 said:
I think the wastegate is staying open . SP staff told me I might need to add preload to the spring. I added about 1/4" of preload on the actuator rod but still only boost to 4psi base boost running on the wastegate spring. SP told me I should add more preload to bring my base boost to 10 psi. This doesn't sound right. I think my wastegate is bad.
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MarkIII4Me;1563618 said:
I dropped the elbow and the downpipe and checked the flapper. It is very smooth and seals good.
---------- Post added at 01:07 AM ---------- Previous post was at 01:05 AM ----------
MRSUPRA;1249192 said:
My actuato arm has a bend in it already. That's how I received it from Sound Performance. Sure I will check the line. I hope that's the problem.
