Noob Time Questions
 

Move question to topic where you deem suitable, So bloke here from Australia looking for info on what power people are making on pump gas 98 octane on a forge built engine
the reason i ask is my car is currently being built and im trying to determine what to do. my goal has always been min 300hp
BUT the car will be BUILT for E85 and im currently working away from home (for the next 18 months ) and there is a race track 15min drive but there is no E85 available within 100's of miles so my question is, Is there an in between
can that i have the best of both worlds ?
my thought process has led me to this, CAN i build a high comp ish (10:1-12:1 CR) engine and run a thick head gasket getting it back around 9:1 CR mark or am i dreaming ?
or am i stuck with building a lower comp engine till the time comes where i can go full E85 ?

Cheers

You are dreaming. Buy 8.6:1 Supertech pistons and run those. BP motors like timing and those will allow you to run the most without issues on pump gas.

Don't forget the connecting rods. Stay off the mighty car mods train.

Choo Choo. As much as I love watching for entertainment, sometimes the lack of information can be irritating, especially since for some people that's 100% of their knowledge base. Brings some weird people out.

Build
 

Building the engine isn't the issue its at what likely power will i be limited to by detonation with higher compression on a pump 98 tune?
i either run 10:1 cr and a really thick head gasket and hope for the best.
or i try and source my owl fuel via Drums to keep E85 tune and run decked head and 12:1 cr for max power response and overall insanity.

I made roughly 300hp (no dyno, based on 1/8th mile trap and the ability to roll on the throttle in third gear and spin 225 rs3's.) on pump gas and a 2560r @22psi. I am expecting a bit more with the same engine using a BW5268. 8.6 cr pistons.

Build
 

So detonation was the limiting factor with that power ? Im running a higher flowing turbo.

No, the 2560 was the limiting factor. Pat makes almost 500 on pump gas and like 30 psi boost. What turbo are you running?

Gen 2 gtx2863r

:nuts:

You don't seem to get it and seem dense... we're being 'nice' and giving you straight forward advice.

Nobody runs "thick" gaskets on these motors. Running a 9:1CR will be a plenty for your gas goals and E85 distant dreams. You'll be limited by timing as stated and won't be able to run high comp. If you run 10:1CR or more, just stick to not having a turbo. BP Motors make the most power with the lowest compression with advanced timing.

I myself have 9.5:1CR and hate life. :party: I won't see much past 14-16psi on my built motor. I feel the need that I must downsize my turbo from a GT2860 to a GT2560.. Or possibly switch to TSE manifold and EFR and still run the same PSI with quick response that is all holy EFR. MOST hp I'll get is 260hp and 240tq or something give or take. Get the lower comp pistons and expect for 300s on a good pump tune with a nice turbo.

Thick HG fucks up the squish band and promotes detonation. If that sounds good to you, then run a thick HG.

Build
 

Thanks Savington for actual relevant information. I guess i didn't know how to word the question.

so build for E85 or pump 98 can't do both without one sacrificing power from from other.

so in saying low comp (8.6 and all the boost still applicable for E85) or would a high comp turbo motor make more power ? In all ranges of rmp ?
i guess this was my original question.

And your 98 octane :ne: our 98 octane. They are measured with a different formula.

Yes, high compression will work with e 85 and make more power. I don't know of anyone who has gone higher than like 10.5 of something. But think about it, you are considering buying fuel by the barrel. This is insane. I built a motor that ran on race gas only. Worst mistake of my life. It was expensive and a pain in the ass, every time I wanted to drive it. Drive 10 kilometers to the burger joint, 20 bucks. Fuck that.

E 85 is not race gas, but the principal is the same if you can't get it on any corner gas station.

Thanks sixshooter i didn't know that. Possibly why when trying to research the power limits of 98 oct i get considerate discrepancy.

The cars 90% race car but road regestered. Back home where i live E85 is plentiful but for the next 18months i live away from home 4 weeks at a time then have a week of rnr, here at work there is a race track 10min drive from my accommodation so im planning on tracking it every week possible. Ive had rotary engines for the last 12 years hence some noobish piston questions.
fuel here is expensive anyway @$1.68 for 98 or $.90 for E85 getting it via the barrel takes it too $1.80L in a 205l drum or $1.60 if i buy 4 drums/pallet.

If you need the ability to run the car on pump gas, you should build with a low-compression piston. The small sacrifice on E85 is well worth the safety while on gas. Building a high-comp motor and then running it on gas will really hamstring it and you will have to be constantly aware of the possibility of detonation. It doesn't sound like fun to me. I plan to run E85 a lot (there's a station 6 blocks from my house), but I still built an 8.6:1 bottom end for my car.

Awesome, thanks guys i guess its 84mm in 8.6:1 while its tuned for 98 octane, :party:

This would be best. Your octane ratings are computed the same as in Europe.

thought about meth injection instead of e85?