Need top end gain!

[turbovanman²]

simon look closer at the turbo. The exhaust side might be chryco but the center section and comp housing aren't. I'd find a good T1 turbo and slide it into the exhaust and find a T2 comp housing. Then hook the water up. It'll make it last much longer.

Good catch, my monitor at work isn't as good as yours I see,

What ^^ he said. +2

[88_pacifica]

yep..he's right it's a t1 exhaust side with the 2.25 SV. I don't know how you got it to work with the T1 style intake you had there. Impressive...

[gvare001]

Got the head back from the machine shop. I guess I'm hardheaded for going with the G head. I just got to find out for myself. Anyhow, until I get a proper calibration for it, what should I set the base timing to, or what other tricks can I do to run it acceptably?

[glhs875]

Got the head back from the machine shop. I guess I'm hardheaded for going with the G head. I just got to find out for myself. Anyhow, until I get a proper calibration for it, what should I set the base timing to, or what other tricks can I do to run it acceptably?

There's nothing wrong with a G head. I run one. I also did a poll on what type of 8V head people were using running 12.5 or quicker in the 1/4, or 8.5 and quicker in the 1/8th. The G head was by far the most used. And also had the best overall ET's.

[gvare001]

Finally some progress, got the HG this evening. I had to do a lot of grinding to the turbo and exhaust manifold to fit the 3rd runner on the two piece. Looks like the spirit of the old 600 will live again, and this time with oversize valves.

[Vigo]

looking good! somebody sell me a complete 2-piece for 125$! :P

[contraption22]

In my testing, the swirl head provides better throttle response. Once they are ported, it's a toss up as to which one is better. If it were a 2.5, I would definitely recommend the G-head just because they seem to have less of a tendency to ping.

I would start out at about 10 degrees of base timing, and advance or retard to suit.

[gvare001]

I finally completed the job, but now I'm having some problems. The car's running rough, and will lean out as soon as it goes into boost. My timing is set at 12TDC, and I'm getting good vacuum pressure, around 18inHG.

[contraption22]

Sound like a Map sensor problem. Check all your vacuum lines.

[mcsvt]

^^Agreed, sounds like it isn't getting a proper signal.

[turbovanman²]

In my testing, the swirl head provides better throttle response. Once they are ported, it's a toss up as to which one is better. If it were a 2.5, I would definitely recommend the G-head just because they seem to have less of a tendency to ping.

I would start out at about 10 degrees of base timing, and advance or retard to suit.

There's nothing wrong with a G head. I run one. I also did a poll on what type of 8V head people were using running 12.5 or quicker in the 1/4, or 8.5 and quicker in the 1/8th. The G head was by far the most used. And also had the best overall ET's.

After my recent issues and the problems- Cal issues, EGT's issues, soft around town etc, I could not recommend a G-head. If you can do your own cals then maybe but stick with the Swirl and you'll be alot happier.

[gvare001]

I'm running out of options, and I'm going nuts! The car still runs rough, and will not go into boost without leaning out pretty bad, it allmost feels like a fuel cutout. I've gone over my timing a few times, I've swap map sensors from my othe SC. Heck I even swap in a 1985 LM and distributor, set the timing and still the same. I'm back to the GLHS LM now. My fuel pressure is ~50psi at idle. I just don't now anymore, would this be an electrical problem, or a fuel problem, I replaced the FF by the way. Also I replace my boost gauge yesterday, re routed the line to manifold pressure and my vacuum presure is not 18mmHG but 16mmHG. I'll really appreciate any input.

[GLHSKEN]

Leaning out in boost could be fuel pump. Base fuel pressure with the vac line disconnected s/b 55psi

[mo' parts]

Sound like a Map sensor problem. Check all your vacuum lines.

most def. sounds map related. are you still running the factory hard plastic lines? very good chance one is cracked. also make sure you have them hooked up properly at the purge solenoid. the feed/source goes on the bottom nipple and the map line connects to the 90' nipple.
also check the rubber line running through the firewall to the map.
also the solenoid for the map is the one located to the far right when looking at the solenoid bank. i would also check to be sure your injector wiring is o.k. looks like you had to rewire them? also be sure that you did not plug the vents on the solenoids(the unused ones) they normally have a little piece of foam on them.
hope it helps

[gvare001]

I went over my map sensor lines and everything appears to be fine. I think I'll take the injectors off and have them inspected. I'll also recheck and reset my timing the factory way. The think that fustrates me the most is not being able to obtain the LM codes, I guess Stage II doesn't flash codes.

[turbovanman²]

Anyway you can run a fuel pressure guage and tape it to the windshield, thats how I figure out bad fuel pumps or find a cheap electrical unit you can hook up temporarily for testing purposes.

[gvare001]

Thanks for the advice Simon, I'll do that firts. I'll tape the fuel gauge to the windshild. I tough about doing that but I couldn't find a hole on the hood, to slip the gauge thru. What I'll do is I'll remove the vent grille.

[gvare001]

Ok I ran the test. At idle my pressure is 49psi. I get the car rolling get it into the boost zone at 5psi, my A/F gauge goes lean all the way, and my pressure guage never goes above 60psi. I repeated the test three time and the same happened.

[turbovanman²]

Ok I ran the test. At idle my pressure is 49psi. I get the car rolling get it into the boost zone at 5psi, my A/F gauge goes lean all the way, and my pressure guage never goes above 60psi. I repeated the test three time and the same happened.

The FPR is a 1:1, so for every pound of boost, you get one psi more of fuel pressure. So 49 psi at idle, would be 50 at 1 psi of boost and 59 at 10 psi of boost, you get the idea.

Another test you can do, turn the key off, jump 12 volts to the coil + side, this turns the fuel pump on, use some needle nose pliers and start to squish the return line, it should dead head around 90-100 psi. LMK what happens.

[87glhs232]

The think that fustrates me the most is not being able to obtain the LM codes, I guess Stage II doesn't flash codes.

Yes, they do.