94 Storm EFI turbo asphalt project

Wanted to post a couple pics and ask a few questions on a project I have going on. RXL throttle bodies, microsquirt, gt3071r. Stock porting, pipes, compression, with wiseco pistons.

Here is what I have so far.

Mocking it up on a junk chassis, and will put in another sled with some lightweight parts.





I cut up an rpc stinger and used the bends to plumb the turbo using the factory 3-1 manifold.



I want to redo this part with a double slip merge collector. It is a little more compact and I think it will seal better. The factory stinger is 1.125 18 ga. Can I use 1.25 16 ga? The id difference is less than an 1/8 with the different gauges. Is there actually an advantage to a slightly bigger stinger into the merge for a dedicated drag sled?

I will mount a wastegate somewhere after the merge collector.

Thanks.

Anyone throw me a bone? Will 1.25" stingers into a merge collector be ok?
Thanks! I want to get some stuff ordered.

sneak said:

Interesting project, I like the microsquirt rather than carbs. I'll throw in my 2 cents since nobody is helping you. Testing needed to determine optimum size. I would start bigger and safer. Smaller: detonation more likely, power comes on quicker, more rpm, maybe more peak power but may fade on longer runs. The turbo plays a part in determining back pressure. Get it sealed well, leaks are bad news with boost. You might ask over in the Cat section, Gus Bohne can be controversial and a basher, but he has lots of experience with turbos on the triple Cats. How much boost?

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Thanks for the reply! I am not trying to get every last ounce of horsepower out of this thing. I would imagine 20 psi would be about 300 hp with a "safe" tune? I will probably do the 1.25 stingers into the double slip merge. And double spring and rtv at the flanges at engine.

As far as the engine itself goes...
Should I look for some 12.9 studs for the base and heads?
Thinking that and having cometic cut some copper gaskets at whatever thickness they recommend to maintain stock compression? That should add some reliability?