I have another problem. The problem is my little .42/.48 AR T3 gets full boost at 5500rpm according to my brand new boost gauge. Engine is D16Y8. I read everywhere that the .42/.48 usually gets full boost around 3500rpm. Me and a friend have ruled out the following problems:

- Boost Gauge
- Boost Controller
- Wastegate(Internal)

I think it could be the fact that my oil return line goes slightly uphill at the fitting. Also, I have an adjustable oil restrictor and I boosted with the oil restricted and then non-restricted and the results seemed the same.

I doubt there is a boost leak, but I really cannot tell. I also have a small exhaust leak at the mani, but I don't think that would cause that drastic of a change in spool. I tried WOT at 3500rpm and my boost gauge reads 0 psi then it slowly builds to 7-8PSI and holds 7-8PSI at 5500rpm.

 

I would be checking for charge pipe leaks.

 

 

If what i think a charge piping leak is.... I do not have any. There is no air escaping from the couplers....

 

leaks else where, vacuum lines?

also whats your timing like, having way retarded timing will create some lag.

 

it may be that....I have uberdata and running a basemap....the basepmap ignition is tuned for about 8 PSI. I put in .8 in the boost retard value.

 

what kinda exhaust you got on the car? Maybe your cat is clogged up?

 

2.25" catback piping with a resonated test pipe........

Ok...I just "re-did" some of my couplers and went out to the highway and did a SAFE 4th gear pull to see how it spools. It got full boost around 3500rpm, but in any other gear, around 500rpm before redline, the boost would drop from 8PSI to 6PSI. My friend and I haven't got a chance to tighten up all the vacuum hoses, but everything should be secure. So it may be vacuum relate around the wastegate/boost controller area.

 

fix your exhaust leak before the turbo. it will help greatly. i bought a hf mani, put it on and turned the car on. 2 minutes later as im letting it warm up, i see where someone jb welded a hole in the manifold. i couldnt hold boost for ----. got a new hf mani with no jb'd holes and i was good to go.

 

yes, if you have an exhaust leak before the turbo, it will KILL spool time, or your internal wg may not be closed all the way.