[Marty Phipps]

Yeah.. I kinda figured some head work on the other motor was going to be necessary..
Once I actually pull the motor out of the donor camaro, I want to see if there's enough room to install larger valves..
I'm pretty limited for camshaft selection, since I wan to retain the efi

Originally Posted by Tom Vaught

Volume of air into the engine is controlled by the engine displacement and the V.E. of the Engine (Think Cylinder Head Flow but Camshaft/ Carburetor can have an effect too).

With your 2 turbos at 8 psi of boost there should be no change as the volume flow would remain the same and the pressure ratio would remain the same therefore no power increase. With the twin turbo set-up, you can actually INCREASE the mass flow going into the engine and the pressure ratio and power will increase dramatically.

Whether a engine has 2 turbos, one large turbo, or a Vortech centrifugal belt driven supercharger, If you put 13.5 psi thru a 330 cfm edelbrock headed 455 engine, you should get the same 863 HP that Luhn Performance got with any of the systems. The twin turbo set-up, if sized right would make the power sooner vs the other systems but at 13.5 psi thru a 330 cfm edelbrock headed 455 engine, you should get the same 863 HP that Luhn Performance got. Mass air flow and fuel are what determines engine power.

Tom Vaught

[Ollie]

OOOps, didn't catch the 92 year in your first post. This fuel pump module is in the 99- 2002 Camaro-Firebird.

[Marty Phipps]

thanks to Kurt Zimmerman, if any of you are interested in my screaming chicken project, you can see a slide show of it in the lobby

[BruceWilkie]

a late 80's early 90's S10/Blazer efi fuel pump mounts much the same as a standard carb in tank pickup. The lock collar and o ring are same as my carbed 84 GP. They way the pump itself mounts there are plenty of pumps that could be substituted or mounting modified to fit your needs. Could even squeeze multiple pumps and use check valves for times when only one pump needed.

[tininjun67]

a boost referenced regulator works just like your stock one. it sees the same vacuum signal your current regulator sees. it will drop fuel pressure when vacuum is applied, then raise pressure when boost is applied.Your stock regulator is already doing that: 57 psi is not where that system operates normally. with the vac line disconnected, the regulator should bump it to 45 psi. add boost, and it's bumping it to 57 psi. your fuel pump may be capable of 100 psi, but it may not make the volume needed to get there under load. I would wait on the aftermarket regulator. I don't know that you would see an increase in pressure like you want to. a "chip" burned for your application would help immensely. Throw the bigger injectors in it and get a tune on the fuel map done already. the stock injectors can only flow so much fuel no matter how much fuel pressure you throw at them. if your budget is tight, get a megasquirt ecu and use it. totally programmable, and not much more cost than a couple "custom chips" would run you in the long run.An aftermarket map sensor isn't needed with the megasquirt until you've gone over 20 psi of boost. you've done really well throwing band aids at this thing, it's time to tune the fuel map. I'm not surprised it falls off at xxx rpm, I think your injectors are maxed out.

[thirdgen455]

Originally Posted by Marty Phipps

Yeah.. I kinda figured some head work on the other motor was going to be necessary..
Once I actually pull the motor out of the donor camaro, I want to see if there's enough room to install larger valves..
I'm pretty limited for camshaft selection, since I wan to retain the efi

you can find a bigger cam, My friend with the turbo z24 has a HUGE cam in his 3.1. I can't remember where he got it but I searched and found the specs 254/246@.05", .62"/.60" lift and 114 separation. He used to have a website but its down now. If it was possible to do to a 3.1 he did it. very impressive rice killer.

you can search around for "Curtis turboz24" and find some posts he's made on J-body forums. Last I talked with him 6 or 7 years ago he was pulling the motor from the z24 and putting it in a Opel GT. He had a bunch of trouble with the fwd trannys and took my advice and went rwd. He did tech work for Haltec.

[GOAT8U2]

I think you're mechanic friend was trying to help you because this setup is in trouble.

EVERY turbo car has a boost referenced fuel pressure regulator.

You're running 8psi on top of your normal static compression with the ECU NOT pulling out timing while under boost. Sounds like a crank killer for whatever pump gas is in your state.

The reason why you thought the injectors where too big was because you don't the have fuel pressure regulator or ECU to properly utilize bigger injectors. Running 57psi of fuel pressure is killing you MPG, maybe your bearings, and not running larger injectors is going to limit your power from the turbos.

Your mechanic friend was accurate, you'll only get so far with this setup before you'll need a new AFPR, ECU, Injectors, Fuel Pump and probably headgaskets when you're done.

Don't believe me, look up the Pontiac Turbo TA built in 1989.

[twov8sandat4]

Which Bosch pump do you have? And where are you reading the fuel pressure from?

[twov8sandat4]

One other thing. Do you have a wideband? That will tell a lot about what is going on with your setup

I agree with Goat8U2. Anyone who has played with Turbo Mitsus knows what's going on

[BruceWilkie]

The only alternate would be a carbed draw-thru system. Requires carbon seal on compressor side, "normal" carb fuel pressure and adequate fuel volume. Easier said than done with your combo. You still need ignition control. Your ecu would need to be "fooled" to think the fuel injection was still working and you would likely still not get proper ignition control when boosted without custom calibration.

An ECU upgrade plus pump/regulator and injectors to match seems the best way.

[Marty Phipps]

I built the system, with the ability to piggy back a mega squirt controller to it if necessary, and I actually have the mega squirt, I still need to get another chip for it to control the iac motor..
More then anything, this 3.1 motor is being used as a "mule" to work out any and all bugs, before I build the larger 3.4 motor to take it's place..
Overall, I'm actually quite pleased at how the car runs, but the top end issue is where I'm stuck at

[GOAT8U2]

There ya go, install the AFPR asap and get going on that MegaSquirt. Then you can run larger injectors and get the Injector Pulse Width appropriate for idle to WOT. If you get the hang of MegaSquirt you might want to consider Speed Density, then pull timing, add boost and hold on. Then add Alky Injection and hold on some more

You'll definitely want a Wideband here to dial in the Megasquirt, I'd recommend an in cockpit AEM which are really cheap shipped. I'm about to install one in the GTO since the LC-1 is a prissy biotch to deal with.

[KEN CROCIE]

If I didn't see it in the post-sorry-but Do you have a fuel pressure gauge that you can read while under boost on the road. You need to have your base fuel pressure + boost pressure at all times at the fuel rail.