Exhaust ????s

[DragulaGN]

I just aquired an 87 GN with a Craig Johnson ta63 and Houston 3" dp. The turbo is pushing 20#s of boost at wot. I was wondering if the Hooker 2.5" exhaust could be choking the motor down when it comes up on boost.

If so, what exhaust would be recommended. It already has a cut out aft the dp.

 

[Thumper]

The hooker exhaust system is a good system as far as flow and sound, it should not be choking it down much if at all. I would say not at all. Let me know if you would like to get rid of it, I may be interested if you decide to move to something else.

thanks
Bill

 

[Hammer231]

Open the cutout and see if there's any difference in performance. Don't think the Hooker catback would be a problem. I've seen guys run well into the 10s with a decent 2 1/2" exhaust.

 

[Turbo1dr]

If you're worried about it choking the engine do an exhaust back pressure test. All you have to do is hook your boost gauge to a pressure port in the exhaust and do a WOT run while looking at the gauge.

 

[Fuelie600]

Do you have an adjustable waste gate? Maybe it's set at 20psi

What fuel are you using? 20psi on pump gas is NOT good

I believe your turbo was built by John Craig ( Limit Engineering )

HTH, Brian

 

[DragulaGN]

The engine only has about 1000 miles on it. It was completely rebuilt by Northeast Turbo. The rebuild included balancing, 3 steel main caps, ARP studs and bolt throughout, stock size forged JE piston, file fit rings, ductile roller cam (208-208) and heavy duty double roller timing chain. The heads are stock iron heads but are O-ringed, ported and polished with oversize S.S. valves. New valve springs, push rods and T&D roller rockers. The intake manifold is port matched and polished. The Throttle body is a 70 mm with a precision plenum and RJC power plate. The injectors are 60lb pen type with custom burned chips. The turbo (which only has about 100 miles on it) is a John Craig 63 series w/ adjustable wastegate actuator. The air induction is a Kenne-Belle with integrated spoiler. The intercooler is a CAS-V2 front mount. The oil saver relocation kit was installed and also Razors alcohol injection system. The ignition is stock with 10mm custom fit plug wires.

 

[Fuelie600]

Have you tried shortening the wastegate rod to increase boost? Make sure your fuel is of sufficient octane. Brian

 

[VadersV6]

Make sure your fuel is of sufficient octane. Brian

He has alky. If you're worried about backpressure, just get an electric cutout installed on the dump tube.