Expected power with this setup?

[turbonetics87]

Hello all. This is my first post here. Back in november I purchased a 1987 turbo coupe. The original owner purchased the car new in 1988 and owned it up until he passed in 2017. The car then sat for 5 years leading up to me purchasing it from a friend of the family. The original owner also had some engine modifications done and I have documents to show it, although the turbo system itself was largely left stock. With the upgraded engine as a basis, I planned my build and am now in the process of installing everything. Time spent sitting certainly had its way with the car as the TPS had gone bad, and the turbo seals were leaking when I decided to park the car to completely go over it. It was also making an unsteady 20+ PSI on a stock turbo, and would occasionally break up. I have since pulled the entire stock turbo system out and done a compression test to verify the engine as healthy. I wanted to give a quick rundown of what the final build sheet will look like, so someone more experienced might be able to tell me an expected, safe power level. Its very evident to me after spending some time with this car that the owner was planning to make some big power in the future, and since the car has fallen into my hands I plan to finish the job. There is WAY more I could share about this car and its story but for now ill stick to whats being done.

TL;DR just need a quick rundown on expected power

Engine details:
Built head by boport
Oversized intake/exhaust valves (stainless/inconel)
Boport stage 2.1 roller cam
Ported/polished
Upgraded springs, seats, retainers (good for 6k rpm)
Engine was blueprinted during the head build, and received upgraded JE piston rings and ARP studs.
Upgraded fuel pump (unknown size, can tell just from the priming noise)

Planned/in progress:
SVO garrett turbo with larger turbonetics compressor housing and 56mm compressor wheel
Stinger FMIC kit
Pimpx standalone w/ AEM wideband
Gnari cast log style ported turbo manifold with external wastegate
FID 725cc injectors

It also looks like the original owner added an aftermarket fuel pressure regulator but I will likely end up replacing/upgrading this to make sure my fuel PSI is correct. 

I shared my planned build with charlie of evergreen turbo and I followed his recommendations to have this unit built. He claimed I would be able to make 350-400hp with this setup on pump gas. That said I definitely plan to add some chassis reinforcements before I go for power. Im changing a lot of things at the same time so naturally my priority is to just get it running correctly on minimal boost. I do have access to the build sheets for the engine so if anyone needs more detailed information I am happy to share.


Thank you

[Stinger]

The likely bottlenecks are going to be the turbo hot side (Charlie tends to run clipped exhaust wheels instead of a proper upgraded/larger exhaust wheel) and the compressor wheel (Charlie tends to run T04B compressor wheels from the 60's which are not efficient at the boost levels we tend to run, and they often surge at low RPM). He clips the wheel to try to increase flow and slow down spool in order to prevent the surge but while it does a marginal job at those things, it does a great job of decreasing the efficiency of the exhaust wheel itself, converting less of the exhaust energy into boost).

If the turbo situation is sorted, the tune is dialed in well, the cam timing is adjusted to put peak power where it should be, you're running proper 3" exhaust with a straight through muffler, etc. then he's in the correct range. 340-365ish on 91 octane, 365-400ish on 93 octane.