JBrown

i have a 3.5 turbo motor based off a 3.0 engine. Full ghl exhaust, k-27 turbo,garettson intercooler,intake ported, cams, fuel head modified by imagine auto. I have about 370hp at the wheels with 12pds of boost. what kind of horsepower would i get if i went to a .9bar spring and a 1 bar spring?Is it worth putting in? thanks John

Brent 930

12psi is .827bar so if you went to a .9bar and it's true to the rating of 13.05psi or 1 psi more could net you another 10hp (x2.5 for 1bar) up top but more down low. Once the turbo starts to flow more and move to the right of the compresser map (going less efficient) your hp/psi will go down. I see around 18hp/psi when it's most efficient but that will almost be cut in half at max power and 1bar or full power. Anyhow it's worth doing and would get you close to that magic 400hp with a 1bar spring)

Sameer

0.9 to 1 bar is alright. Just make sure you have good gas, adequate cooling, a good intercooler like a Kokeln or Garretson

Sameer

I forgot to mention, turn up your CO to abt 3-4%

OliverM

I just bought a stock 1986 930 with rebuilt engine and trans. Would I get a noticeable jump in hp with a one bar spring? And, if so, do I have to add intercooler or extra oil coller.
Oliver M

Sameer

I and most of us would replace your stock with a bigger intercooler if your going to 1 bar of boost pressure. I would recommend the Kokeln intercooler which is very very good already. Other mods I would do in the near future:

Fabspeed muffler
GHL or B&B headers
K&N air filter
Camshafts
Additional oil cooler-
Fuel head mod and/or Andial fuel enrichment(if you do all the above you'd need to do the fuel head mod o at least get the Andial fuel enrichment.)
Replace all your old cables, injectors, plugs etc etc to get back the power you lost due to wear and tear.

I would only contact the 2 reputable tuners below.

Stephen at ImagineAuto
or
Steve at Rennsport

You will be blowing most cars off the road with the mods mentioned above in be around the 400bhp mark.

Sameer

OliverM,
I forgot one very important upgrade,

Your old K26(3ldz) turbo has to go. Get the K27-7200 turbo from Stephen. Spools up much quicker and can flow more air for more power.

Hot Air

Would that package be considered a phase I or II modification based on Stephen's packages at ImagineAuto? If one is going that far, a) how much added hp is a twin plug going to add and b) at what point is an upgrade in the clutch going to be required?

- Dan