Irizarr

I think you missed the part where I said my engine needs a rebuild regardless of what my plans are for turboing the car. I'm taking this opportunity to build it with forged internals for power. I want 250whp+ because I can get that on a healthy engine with stock internals, so not getting at least 250 or more would be a waste of the build. Beyond that, I don't know what I want because it depends on other factors that are more important to me. Basically at this point I need to for sure decide on a responsive turbo that will take full advantage of the forged internals. After that I can see what power that turbo is capable of making safely, and then that would be my power goal. The compression question stems from a desire to do what's best for spool up and reliability on both E85 and potentially pump gas, if rarely.

Gee Emm

No I didn't. Re-read my post.

Irizarr

I read your post a few times already. As if that's a helpful thing to say in an effort to resolve a miscommunication. To be honest, that's what most of this thread is, and it's getting tiring. It doesn't need to be that way. I don't even care who's at fault, I'm legitimately trying my best here and genuinely looking for help and advice based on my goals. In return I'm often afforded snide remarks, sarcasm, and generally unhelpful comments. I posted here because I thought there was a good chance the people in this community could help me figure a few things out. That is quickly proving to not be true. I think I'll go back to treating this site like an archive rather than an interactive forum and continue researching elsewhere. Hopefully I'll be able to find the answers I'm looking for before I'm ready to start all this work on the car. Have a good one everybody. I wish you the best.

The Australian

You might find some useful info here: Dsport article

CR does make a difference, but unless you have the budget to test multiple combinations, it can be better use of your $$ to select a combination that works without trying to find the limits.

250hp = 2560 and you’d probably be fine with a CR between 8.5 and 9.5.

Mr Plow

I went through the thread - tried playing devil's advocate on your side etc. but have been left agreeing with the concensus. You've not decided your end goals in any measurable form from which people could then opine on an optimal solution.
If you don't set measurable performance targets, a rough budget, setup and intended use of the car etc. then people can only provide the same vague responses as fit your vague questions. Reading between the threads you want an optimal engine (one person's optimal is another bane so zero measurable goal) that will last years (no idea how its being driven or the mileage in these years - zero measurable goal), no idea what horsepower you want but already guessing turbos, want the turbo run maxed out (see conflict with "last for years" previously).

My early enquiries on here were vague and the responses indicated to me that I did not know what I wanted. I found it helpful in the end and the focus allowed me to do the research on many fronts before asking more questions and pretty much hit all my goals in the first hit - Actually made more reliable power than expected and the car performs its planned uses better than expected... so far.

If I were you and someone local to me had a tubo miata - I'd try to get out in it even as a passenger which may help you decide on measurable performance and use goals. Then it will be much easier to discuss potential routes to them.

emilio700

iTrader: (3)

Irizarr,

Sorry if I missed it, but what is the minimum octane you will ever run in this engine? That is what will dictate compression ratio. Your plan to run E85 occasionally has no bearing. E85 likes compression ratio but thats irrelevant the moment you pour pump gas into the tank.

Also, what country and state? Different octane ratings systems