ok here it goes I picked up a SVO a few months ago because it was inexpensive and already had a T3/T4 ,Stinger FMIC, ported intake , Big injectors, Walbro fuel pump, bo port ported head 2.5 cam , 3 in downpipie however going into a 2.5 in pipe and a stockish looking cat. Older PIMP (that needs a good deal of tuning)upgraded 95 cobra brakes and spindles super nice interior etc. I am a auto technician and have occasional access to a dyno so I ran it as is at 13psi where previous owner had gillis valve set. It is a lot of good parts with many issues as well ..... Blowing oil, terrible idle high and wandering, almost always rich,low fuel mileage etc.
anyway run as is for a baseline on a fairly new Dynojet Max power 251.77 RWHP @4800 then dips and is back up by 6000rpm Max torque 277.50 4800rpm starting to iron out all the issues 18 psi definately pulls a lot harder, been working here and there with the tune thanks to shannon for getting me the needed hardware to tune the pimp.
working on the tune and running 17-18 psi idles good. A/F is better running low 11.x under boost. I am now recording 288.3 hp @ 5600 rpm. My intake is fully ported but running a stock E6. Also at 3200 rpm im only seeing 5 psi / full boost around 5000 rpm. Do these numbers seem in the ball park for normal (turbo is a T3/T4 50 trim I think .63 A/R). id like 300-325 WHP. Im wondering if I can get there with a modern turbo and better exhaust (id like the boost to come in a little earlier.
50 trim is plenty modern. I just saw an SVO make 440 hp with one on a dyno last week.
Full boost should hit around 3200-3500 if you put it in 3rd gear and floor it at 2500 rpm. What you reported above is about what it would do in 1st gear. Only things that can slow down spool is exhaust leaks pre-turbo (big ones), and a wastegate that's not adjusted properly and isn't ever fully closed. Cam timing can also do it but it wouldn't be making 288 hp if that was the case.
What's at least partially at fault for the slow spool is your restrictive exhaust. Our 3" exhaust would bring it in sooner for sure, likely around 500rpm sooner. It will also add 35-55hp depending on how the cat and mufflers you have now are flowing. That alone will get you over 300 hp.