Which Cylinder head?

[DBMajik]

I want to go to E85 for the 108 octane so I won't be dealing with knock but still a little confused on what I need to do to the car to make it compatible. Where should I go to get the fuel rail treated?



I haven't heard of the fuel rail needing to be treated for E85. Anyone heard of it?

[iceminion]

Andrew, I suggest the 1G 7bolt head, as I understand it, it flows the best. And on turbo cars, flow is everything. I will go out to the garage and take some pics of both heads and post em later tonight.

The 2g head probably has better response when off boost, but comon, boost is life, go for alot of boost.

I agree with JET, I would go with forged internals, you wont regret it, the 1G rods are cast, and they can bend/break, and the 2g pistons are cast also, they can melt easier.

E85 - Let me answer this once and for all: you can run E85 in any car, all you need to do is re-program the ECU (or use an SAFC) People have been running E85 in cars for a long time with no problems, regular pump gas has 10% Ethanol, sometimes more.

I dont know why everybody assumes E85 will corrode the fuel system, it wont.

If I am incorrect on anything I said, feel free to correct me, lets keep the correct facts in circulation, not automotive superstition.

[Jakey]

Andrew, I suggest the 1G 7bolt head, as I understand it, it flows the best. And on turbo cars, flow is everything.

Have you read any of the other posts in this thread regarding port size and air velocity?

[iceminion]

Yes, I have, but you have to find a happy medium between velocity and flow.

M.A.P. has a 500+awhp car, and they chose the 1g 7bolt head, because it "flows the best" I would put my money on the head with the biggest ports if I was using a huge turbo, if I had a t25/t28 the 2g head would probably work better.

[Andrew7dg]

Then no you haven't been reading the previous threads....

I am not going for a huge turbo to make huge amounts of horse power. That is not the point of the thread. I already know that is possible to make huge horsepower with these engine with a huge turbo... I have realized that my car isn't going to be the fastest out there.

Also I have a 6 bolt motor with a 6 bolt head, why would I want a 7 bolt head? Did i forget to mention I had a 90 eclipse...wait i did sorry....

This will turn into my daily driver so I want to enjoy the car in all areas of the rpm range. Not just the top rpm or top hp range. I am sinking all of my money into another street project.

So it sounds like to me the 2g head will work better for me then the 1g so far....

Also You can take pictures of them as much as you want. I have seen pictures that compair both of the heads but I don't want to see size...
If you, look at both heads and see which one has better entry of air. What I have been told and have seen is that the 2g has better entry of intake. the 1g head has a horrible angle. I believe running more boost just covers up this problem in the long run.
Because of the angle of entry, the High HP cars I think are running the 2g head ported so that it flows better and in the long run will outflow the 1g .


"If I am incorrect on anything I said, feel free to correct me, lets keep the correct facts in circulation, not automotive superstition."

Thank you for posting this, this is my thoughts entirely, however if you are going to say this please back up your thoughts.

The idea that E85 "Won't" corrode your fuel system has to have backing. Why won't it? from what I understand, E85 is like Alcohol and it corrodes aluminum. Our fuel system is mostly aluminum and the head is aluminum. I thought you had to treat the fuel rail so that it doesn't corrode because fuel will constantly sit in it? Since my gas tank is metal (lucky 2g have plastic), won't I have to treat that? For the computer issue, I have that solved with a full stand alone system to control air and spark. :cool:

But if what you say is true, I have all the components to make the car run on E85? I don't need to do any more exept just fill it up and tune the computer (well I need bigger injectors ofcourse)? That would be sweet!

Ok back to the idea of generating exhaust gas, So did we determin that higher compression won't make the turbo spool faster and if so, it would be minimum and not noticable.
And if it did, the reason is that on the exhaust stroke it is pushing the exhaust out a touch faster because of the compression, not because of the amount of exhaust. This is more believable because if the 1g had lots of fuel unburned it would plug up the cat and there would be massive amount of backfires.

Ok I am going to talk NOT in racing terms but on highway crusing which is off boost. Would I be getting better MPG then because the car has higher compression and generating more power because of the compression.
For example on a lower compression, say going up hill with the cruise control set, the car would be forced to use more fuel in order to get more power from the 7:8. The 8:5 will use less fuel because it is gennerating more power per combustion. This I think would also be at an unnoticable level of fuel consumption, but fun to talk about.

Sorry about the "kick butt statement" I ment it would have the advantage. I don't want to make this sound like it will have a huge advantage. I know that it would be very minimum.

And the turbo differences between the T25 T28 is all on efficiency which is for another thread.

[iceminion]

Then no you haven't been reading the previous threads....

I am not going for a huge turbo to make huge amounts of horse power.
Thanks for accusing me of not reading.

I am thinking if I got 350-450hp I will be very very happy

Listen, 350-450HP on the Dyno, ANY Dyno is huge engine HP. and you can use a 2g head, but you are going to have to make up for the restriction in the system somewhere else, bigger turbo/more boost.

Also I have a 6 bolt motor with a 6 bolt head, why would I want a 7 bolt head? Did i forget to mention I had a 90 eclipse...wait i did sorry....

The 1g 7-bolt head outflows/out performs the 1g 6-bolt head, its designed much better, everything bolts up fine, the only thing you will have to do is take it to a machine shop, or find someone with a drill press and have them drill out the head stud holes (BTW, you will have to do this with a 2g head also)(6-bolt=12mm/7-bolt=11mm(i think))

E85 will not damage your fuel system, everyone in minnesota runs E10(with the exception of some special stations), if what you feared about E85 where true, then E10 would also corrode the system, which it does not.....Still dont believe me? go to a gas station, fill up a large glass jar of E85, take an old fuel rail, put it in the jar, seal, wait and see. I did this test myself, and now I have a clean fuel rail, and one hell of a molotov cocktail to throw at all of the e85 haters out there!

[iceminion]

Dont build your motor with fuel economy in mind, there really is no point.

Build your motor to perform well for the HP that you want, I would go with the 8.5:1 pistons, 9 is a little steep for me.

if you want to have better fuel economy, you can order up a taller 5th gear for your car

http://www.teamrip.com/GENUINE_FACTORY_AWD_PARTS.html

(1/3rd way down the page)

10% taller 5th gear, they claim 27-30mpg, the cool part of it, is you can install it really easily, all the other gears are tough to take off.

[HiImBrian]

what do you think I should do? I value any opinion I get.

Well I struggled with which head to put on my 98 gsx. I knew the 1g has bigger ports but the 2 g has its benifits as well. In the end I decided to go with neither. I picked the evoIII head and Im porting it out. That way I have the best of both worlds. Shorter runners without sacrificing smaller ports. I also took i mind my own theory of similar parts should be kept together. The evoIII head and 2h head are the same except the evoIII has bigger cams and shorter runners.

[EclipseGST]

Dont build your motor with fuel economy in mind, there really is no point.

What are you talking about?

As long as the car is tuned it will have good gas mileage. Doesnt matter how much power it has, if its on pump gas, cruising down the highway, how is hurting the fuel economy?

I just delivered a car to a guy that has me install a roll cage and fix some other stuff on his car, the car ran 11.8 on 19psi and pump. I had to drive it 300 miles to deliver. The car used 10.4 gallons of gas. Tell me that car does not get good fuel economy because it has power.

As far as the head decision goes... I personally like the 2g head. The bowl, valve angles like you said, smaller ports and so forth. I gasket matched my intake ports to a 1g intake manifold which possibly hurt it but I am going for the most flow I can get. I dont think anyone as ever done the test, stock head for stock head to see the power difference. Would be interesting to see in my opinion.

[DBMajik]

There was a test between heads. If I remember correctly, Polk Performance did it. Unfortunately I read it a long time ago on tuners and can't find it again. It's a little fuzzy from my head so take these numbers with a grain of salt. The 2g head only flowed 30 cfm less in stock form. However, the 1g head only flowed more 5500+rpm. Again, with a grain of salt.

My opinion, Andrew, is for you to go with the 2g head. That way, after you complete your goals; all you have to do is port the head and it will by far outflow any 1g head. Ported or not. That is, if you decide you should want more power after that.

As far as the E85 corrosion problem, you might as well get Viton O rings since you'll need a larger fuel pump and injectors anyway. It's up to you if you want to use the rubber fuel lines or not. I have used E85 but not enough to actually test the corrosiveness on rubber. I'd go with stainless braided lines anyway, it's a cleaner look and you get more fuel with the bigger lines. Also, this will aid when you install an adjustable fuel pressure regulator.