I was hoping one of you guys could help me narrow down my problem here. I just did a complete engine swap and am running a GT40 now. I had a few leaks I had to take care of to get the car to idle right but once those were taken care of the car started and idled just fine. Now when I take the car out for a small stroll around the block I notice i can't get the car to build any boost. It's actually barely getting to the 0psi mark when given gas. Where could this be coming from and waht can I do to narrow it down to a certain area or problem? I would think if it was on the exhaust side of things I would at least build a little boost and could hear a pretty loud exhaust leak. Can you boost leak test a rx7? If so how do you go about doing that? Any suggestion would be great. Thanks guys.

 

http://www.autosportracetech.com/RX-...leshooting.htm

 

hmm thats a very helpful little hint. No the car isn't tuned as of right now. I have a base map in place but the car is running rediculous rich right now. I listed my setup below. Please let me know what you think.

750 Primarys
1000CC Secondaries
Walbro 255lph pump
Power FC
GT40 Turbo
3" Turbo Back w/no cat
Very aggressive port

Would the overly rich tune cause the car not to reach 0psi? Obviously I'm not out to boost on base map tune but I want to make sure there are no major problems before paying someone to come out and tune the car and end up having him sit there for hours while I figure out boost leaks or something else. Anyway of testing this? I used to do a lot of work on DSM where we would cap the turbo off and pump compressed air into it and listen for leaks in the system that way. Would this work? Or would I be wasiting my time since technically the car would be making some boost even if their was a small boost leak somewhere. Any advice would be very helpful.

 

You are not ready for a tune. It sounds to me as if you either have something piped wrong, or have a leak somewhere.

 

I figured I wasn't ready for tuning that why I am asking on ways to narrow down the leak or figure out whats wrong.

 

This is how i tested my setup for leaks.



Ingredients:
3" Rubber end cap - can be found in plumbing section of hardware store
shrader tire valve

Drill the rubber end cap about 4 sizes smaller than the shrader, then push through and thread the nuts.
Attach to any pipe AFTER the turbo's (as close to the turbos as possible), and tighten hose clamp down.

Get an air compressor, and start searching for the leaks.
Its about 4 dollars in parts.

 

You can also use the Fighter's Garage boost tester -

http://www.fighters-garage.com/universal.html

He'll make one any size you need for your turbo. It's a nice hardy tool, has the pressure gauge and everything.

Dale

 

OK so this should cover from the intake to the engine. Any good way of testing from the Exhaust manifold back? Obviously not the boost leak tester but any other good ideas I might use?

Thank you very much for the boost leak tester info. Thats the same way we did it with the other cars I worked on but I wasn't sure if it worked the same way with a rotary. Much appericiated.

 

^ I don't have the pic right now, but I think it was Dudemaan who built a custom pressure tester that attaches to the lower intake manifold. He used a sheet of aluminum, cut out holes for the studs to go through, and then drilled and tapped 4 holes, on each one he installed a valve for an air compressor hose to hook up to so you can test each runner individually.

I used this one: www.boostpro.net/prodtester.html , universal tester. They're all the same really. It also helps to spray soapy water around while you have the intake pressurized.