JIM@foreign affairs HEADS!

[SC V6]

I have had these for only a little while, and I can already notice the difference.. they are great.. how many of u people have these installed?

[kondo]

what do the new heads change the compression to?
How much boost can you safely run?

[Jackass-Jeff]

I think the CR was something around 8:1 or 8.5:1

[Jaimster]

?

[cdssolara]

I've got the heads, and so far they are working out great. My car definitely has more power, but it's hard to say if what I feel is due to the heads or going from a 5.5 lb pulley to a 7 lb pulley. Regardless, I wouldn't be able to even run a 7 lb pulley safely on CA's 91 octane premium without the lowered compression that the heads provide. By the way, according to Jim the compression with the heads is 9.3 or 9.4:1.

I have had too many work and family obligations to really take the car out and play with it yet. From the driving I've done, I can say that the car may have lost a small amount of power below 2000 rpm, but it's hardly noticeable. From 2000 to 3000 rpm it pulls pretty hard, but not much more than before. At 3000-3500 rpm, there is a huge kick that the car didn't have before. I can definitely feel it pushing me back in my seat now. I'm really thinking seriously about getting headers to completely open up the exhaust and maximize the gains. Where will this all stop?

[shidosha01]

I've searched all over trying to find Jim@foreign affairs. Does anyone have his number? Please email or send private message to me.

thanks...

[SC V6]

I love the heads... they lower the compression... and u can safely run the 7 pound pulley... its great

[cdssolara]

I've searched all over trying to find Jim@foreign affairs. Does anyone have his number? Please email or send private message to me.

thanks...

Jim's email address is ForeignAffairs@aol.com. He usually responds pretty quickly. Try him at that address. If you want to call him, the number for his shop is 503-236-2871. He's located in Portland OR.

[impactX]

I've got the heads, and so far they are working out great. My car definitely has more power, but it's hard to say if what I feel is due to the heads or going from a 5.5 lb pulley to a 7 lb pulley. Regardless, I wouldn't be able to even run a 7 lb pulley safely on CA's 91 octane premium without the lowered compression that the heads provide. By the way, according to Jim the compression with the heads is 9.3 or 9.4:1.

Of course it's because of the 7lb pulley!

When you lower the CR, you lose power if you are going N/A. Running high compression NA puts a lot more stress on the engine components than running forced induction with lower CR. That's what the heads are for: putting less stress on the engine components allowing you to put a smaller pulley to generate more horses.

[cdssolara]

I've got the heads, and so far they are working out great. My car definitely has more power, but it's hard to say if what I feel is due to the heads or going from a 5.5 lb pulley to a 7 lb pulley. Regardless, I wouldn't be able to even run a 7 lb pulley safely on CA's 91 octane premium without the lowered compression that the heads provide. By the way, according to Jim the compression with the heads is 9.3 or 9.4:1.

Of course it's because of the 7lb pulley!

When you lower the CR, you lose power if you are going N/A. Running high compression NA puts a lot more stress on the engine components than running forced induction with lower CR. That's what the heads are for: putting less stress on the engine components allowing you to put a smaller pulley to generate more horses.

You're correct about the effect of simply lowering the CR. I probably should have been clearer in my statement about where the power was coming from. Jim@FA said that there would be a synergistic effect because the headers would flow better than the stock set. He assured me that I would get more power even if I had stayed with my 5.5 psi pulley. By going to an even smaller pulley, I would get more power, but that would also be augmented due to the better flow of the headers.

[EricSol]

My cars hp is so well documented I am just going to bolt on the heads, no other changes and dyno. We will then know the true gain.

[Ragtop George]

When will you be installing the heads?

George

[EricSol]

2 weeks

When will you be installing the heads?

George

[rapsux2000]

If I just put in the heads, and make no other internal changes I should be okay? I'll be using an Apexi Safc2, catback ehaust, but that's all. If I get a 7psi pulley, what else should I do to protect the car?

[cdssolara]

If I just put in the heads, and make no other internal changes I should be okay? I'll be using an Apexi Safc2, catback ehaust, but that's all. If I get a 7psi pulley, what else should I do to protect the car?

If you're running a stock, or even 5.5 psi pulley, you should be fine even if you do nothing else besides adjusting the fuel delivery using the S-AFC2. However, if you go with higher boost, you'll probably be doing yourself a favor by doing something to increase fuel delivery even further. Bigger injectors would probably be the best alternative, and possibly increasing fuel pressure. Also, think about getting the JPP headers and exhaust, as they'll remove all the restrictions from your exhaust system that can add backpressure. In addition, it's been documented that they can add 30 whp, so they'll maximize the benefits of all your other mods.