I've been screwed over! High Compression/TT/E85 only option.
 

Almost two year ago my built VQ35DE TT hydrolocked and bent a connecting rod @ 40mph. While my car was at Lethal Performance in San Antonio, TX, the business was sold to PerformanceHQ. My car was transported without my knowledge, calls/visits were dodge by the previous owner turned manager, and my engine was in pieces for months for shop non payment. While all engine parts were order, it was soon discovered by only me that my special order Z1/Wiseco pistons were 11:1 96.5mm. Being that it has been over 20 months, there is NO way to return piston. Taking into consideration that there is no real market for .040/96.5 HCR pistons. I am stuck with upgrading to E85 for my GTM kit Garrett GT2871r's.

After doing some compression math with stock .7mm head gasket I will have a 12.1:1 compression. So my route of build will be 1200cc AUS injectors, dual AEM E85 320lph, fuel rail. My hope is to at least reach 12lbs. IDK

So my questions are:

Has anyone seen a build like this? What do you know about it? Should I get a thicker head gasket and if so what is too thick? I don't want to elongate screw holes if possible. head/motor have been worked twice. What max boost should I hope for? I know this is a lot but ANY INSIGHT WOULD HELP.

You can run on 93 pump gas. I have 11:1 wiesco Pistons and run 23psi on 93. Obviously you will make more power on E85 but it would still be ok on gas

My first question is what are your power goals? E85 with high compression and boost will be a good combo because you don't get spark knock with E85. Knock is what you have to worry about with high compression and boost. Now with that being said high compression engines will make significantly more hp per lb of boost than with a typical low compression boost combo. So you can run lower boost psi levels to make the power you want. My guess with a 320lph pump and 1200cc injectors you would be looking at around 600whp max with E85. If you want more power I would suggest going with a much larger pump or twin pump combo to keep up with the 37% more fuel E85 requires. The 1200cc injectors should be good up to around 700whp with E85. If you are looking to make more power with the setup you already have run C16 instead of E85. But that gets expensive real quick depending on how much you drive it. Good luck man keep us posted!

That's actually bizarre to hear. Z1 told me I could make power, but they were referencing 370Z which come stock 11:1 and +5mm stroke difference. I was also told that the margin for tuning errors was small for this combination. What's the secret?

500hp was where I was before so that's a great start! I guess I wanted to know if I still had the ability to grow on this short block setup. I've heard someone say that HRC and boost is the future. lol idk. C16 is too expensive and I'll be daily driving this around the Norfolk area when I move there. twin pumps is the route I am going but I'll more than likely start with a single 320lph pump and save for the next step. If I hear more on the HRC/TT+ 93octane, I will probably flex fuel down the road. My situation right now is Cometic HR 97mm/ 1.016mm thickness or OEM .7mm thickness, or my engine shop says they can build thicker gasket for me if I buy another OEM set (cheaper). thoughts? :dunno: I keep y'all post but I'll be out of town of a month caring for my sister who just about beat Leukemia. :dance:

I'd stick with it as is and not worry about the hg's. As u know doing hg on that motor is very labor intensive. For what your going to gain going with a thicker gasket is not worth the reward in my book. Put E85 in the fuel tank tune it and call it day until u can upgrade the fuel system to make bigger power. Just my $.02.

I'm actually building the motor myself for the second time. Block is on the stand as I type. I just tested the OE head gasket and it's too small in diameter. Cometic it is.

I would look into doing HKS hg's. I've heard of people having problems with the Cometics. Maybe that was some time ago and they have changed since idk. U could also run the HR hg's just have to have the proper machine work done. I'm running HKS hg's and haven't had a problem. I've read about a lot of people prefering the HKS gaskets so that's what I went with.

I think those Cometics issues where like over two years ago. Dynosty has speced their own but not sure if they are still available. Soooo....HKS wins by default ;)

I didn't find HKS headgaskets for HR, so I went with Cometic v3 just recently. Got a link?

Edit: NVM, OP is a DE. I'll be doing a high compression TT HR build on E70(85), will post results once we get the motor back together and broken in.

There is no secret; if you run high compression, pump gas, and high boost, you are asking for trouble. You can hope the knock sensor and a good tune holds it all together, but...

Race gas or E85 is the ticket for you if you can easily source either. And as stated above, use an HKS headgasket and L19s.

I am getting ready to build my block. Good to know there is someone close to Austin that is going through these pains and has this experience.

Right on! Building it is always fun, but this time I am on a time crunch. I have a tote full of nuts & bolts all mixed up by the shop. With that and a damaged front-end by the shop, it's a damn nightmare! Unfortunately, I'm moving to Norfolk in a couple of months and I won't be starting it in Texas. I don't have to money to buy E85 parts and tune atm.


https://cimg1.ibsrv.net/gimg/my350z....79df511780.jpg

You are perfectly fine on 93, and it should be awesome power curve

^ disagree; will have to limit boost and pull timing. Power will be limited on 93 (on a safe tune).

Ignore Raj at your peril. He's done far more than most with his car.

ok? And what's the power he is wanting to hit? -700 should be just fine, its not rocket science anymore as long as you have a good tuner.
I personally ran 10.6:1 CR at 621whp on 93 for 3 years no issues.
New build Im aiming low boost 700whp 10.5CR on 93, and then obviously much more on e85 high boost.



The only thing I can find OP is looking for is 500whp and that is peanuts on 93 with 11:1. Topspeed has tuned a few 370z with their 11:1 stock to around 650s on 93, no issues.

The question is whats his end goal, if it is 500-699whp on 93 , FontZ, I would not worry about it because personally I would not have even went below 11:1 CR. It'll make your power curve and bottom end feel great