Im looking to rebuild my first VQ35DE to go in my new z, looking at z1 rebuild kit in the further future i do want to do a turbocharged setup on this engine the options the rebuild kit gives me for the compression ratio is 8.8 and 11.0 so just looking for advice should i get the 8.8cr rebuild and drive my car N/A while i wait for the turbo to be in the budget and will that be safe to do so? or should i use the 11.0CR N/A for a lot longer then take out the engine to swap to the lower CR?
Thanks guys!

 

If you are positive you are going turbo later on I would opt for the 8.8 on this rebuild, and tolerate it until I could get the turbo done. No point in spending the money twice.

 

You’ll hate the car at 8.8 : 1 it’ll feel sooooooo slow…

I would do 11:1 and plan on low / lower boost.

How do you plan to tune?

What fuel will you be using?

Low compression pistons for boost are sorta an older misnomer and people are boosting well into the 12:1 ranges with success … my caveat here is that e85 is the (literally & figuratively) the driving force of higher CR and boost.

Further, tuning technology has gotten significantly better and ECUs are much more capible of detecting knock and restricting the engine from grenading itself.

Last - obviously knock / detonation will be the thing that kills your engine and if you must use gasoline (such as a 91octane) consider using water methanol as well. For what it’s worth - I put down 568hp on 17psi of boost on 91 octane here in colorado (albeit on 9:1 cr) and I ran out of fuel pump … so if you plan to be under 600hp, 11:1 cr is going to take 12psi to 15psi of boost to reach 600hp.

 

Good points already posted above.

With the improvements in tuning, it's much more achievable to boost on a higher CR with good fuel.

I'm on 11:1 single turbo. 93 octane pump gas car made 536whp at 11psi and 607whp at 13psi (with boostane added for safety).

Best part is that the car is completely reasonable to drive out of boost; something you won't get on a low CR. There are times I drive the car for an extended period and rarely (maybe once or twice) get into boost.

 

Like Bealljk said, you will Hate 8.8 CR

I'm a supercharger Guy,

With a totally Stock Motor, Vortech Sc-Trim, 20psi at 7100, made 508whp/420wtq, 93 octane, 17 degrees full advance,
and 577whp/445wtq on C16 Race Gas, 24 degrees full advance

I now have a Built Motor, 11:1CR, Vortech V7 YSi-Trim-Trim, 36psi@8000rpm, Link G4X ECU
and 850+whp/650+wtq on Q16 Race Gas, 21 degrees full advance, and more left in it.

 

For what it’s worth … I’m not saying going 8.8 : 1 is a bad idea - especially if you’re gonna turbo and go big big boost in the very near future … and even with better engine tuning & rescue features 8.8 : 1 is fine … I run closer to 8.8 than I do 11 so I have no room to talk! So X2’s advice / thoughts / guidance isnt wrong

 

Thanks for the suggestion. I will keep it in my mind.