I am in the process of taking off my S/C and putting in a Stage 1 NA block. My question is... Is a 11:1 compression ratio too much for 91 pump gas? The last thing I want for my DD is to have detonation issues.

If you think 11:1 is too much, are there any aftermarket pistons around a 10.5:1 or stock 10.3:1? I can't seem to find any.

Just a note, there is no 93 available in SoCal.

Thanks for the input.

 

You could always bring back the timing to prevent detonation, right?

I'm in Cali so I know what you are talking about in regards to gas. A good resource to speak with is GT Motorsports in Rancho Cucamonga. Ask for Sam as he is the lead tuner.

He tuned my Turbonetics 350Z and he is very knowledgable on the VQ engine.

 

you can have pistons made for any compression that you want, so dont let in stock ratios be the only thing you are looking at.

 

Thanks for the info.


That is true, but I would worry about the timing being too retarded and causing other issues... like being sluggish and running too hot. I will give Sam a call.


Good to know, you have any links for custom pistons?

 

I drive my 11.5:1 w/ UpRev very often.

 

Yeah but you're in New Jersey. What octane do you fill-up with?

 

11.1 is still relatively (keyword relative) conservative. Granted its a push up from 10.3, but I would imagine you wouldn't have too many issues DD'ing a well tuned setup provided your tuner doesn't push too far for all out numbers.

But the question you should ask is why? NA power is cool but what is it your really looking for?

BTW: I'm at 11.3 and have had no problems on CA's 91.

 

True, I forgot. I think I have a 91 map, but yea, I use 93. Still, as long as the tune was good, you should be straight.

 

I am at 11:1 in cali. 91 octane.

I think the new 37's are 11:1 from factory so no worries.

 

Taking the FI off and just going back to a somewhat stock NA setup. Getting a new block and it comes with 11:1 compression. Just want to see if anyone else was running that safely on 91 octane, or had knowledge pertaining to it.

The car will be tuned with UpRev; makes me more comfortable that you are at 11.3:1 and doing fine.

 

why removing the SC?

 

im fully built with 11:1 DD'n my g with an osiris tune......using 93 octane here in SC

 

wish 93 was an option around here

 

You guys don't have E85 in Cali? 11:1 with the Vortech on E85 would be nice.

 

Been thinnking about that for a while, but doesn't look like i'm going FI .

 

I'm also 11:1 for the past year or so with no problem. That being said i'm going to be adding a direct port water injection very soon to achieve something else as well as potentially venturing into E85. There are a few stations here in the bay area.