Miata Piston thread...revisited

[SpoolinPro93]

Ok here is the list Jesse gave me:
90-93 Protege pistons = 8.8:1
94 Protege pistons = 9.0:1
94-97 Miata Pistons = 9.0:1
99-00 Miata pistons = 9.5:1
01+ Miata pistons = 10.0:1

I'd be interested in the 99-00 pistons because of the little bit of an increase in compression ratio and possibility of finding aftermarket forged ones or something. My question: do these fit directly into the Protege?

[JesseSays]

yes

[SpoolinPro93]

Originally posted by JesseSays
yes

Cool, now is there any good sites that sells those pistons overbored?

[Identity_X]

Why would you want to increase the compression ration when you are running a turbo?

[JesseSays]

Originally posted by Identity_X
Why would you want to increase the compression ration when you are running a turbo?

hmmm, off the top of my head...

1) better spool up
2) better gas mileage
3) more power
4) more efficient
5) more off-boost power

[Identity_X]

What exactly determines the compression? Is it the pistons, cams, or combination of both? I am asking because I am SURE that I've read posts where it was mentioned numerous times that high compression cams (more aggressive cams) are not turbo firendly....wouldn't that concept be the same for higher compression pistons or am I missing something here?

[charles]

cams don't increase compression. True you don't want overlap on a turbo

[91ProtegeLX]

Compression is like that amount of air & fuel you fit into the cylinder and compress it into a 1" space. For example, the piston moves down 11" and that 11" is filled with the air and fuel mixture, then the piston moves back up and compresses the air and fuel mixture into a 1" space, giving you an 11:1 compression ratio. Now this is what I was taught in my auto class. So I guess the higher compression ratio that you can have will give you more air and fuel to compress thus making more power.

If im wrong PLEASE correct me.

[JesseSays]

Originally posted by Identity_X
What exactly determines the compression? Is it the pistons, cams, or combination of both? I am asking because I am SURE that I've read posts where it was mentioned numerous times that high compression cams (more aggressive cams) are not turbo firendly....wouldn't that concept be the same for higher compression pistons or am I missing something here?

combonation, depending on what type of compression you're talking about.

Static compression is based solely off the pistons and head. Dynamic compression includes cams and cam timing as well as the others.

[JesseSays]

http://victorylibrary.com/mopar/cam-tech-c.htm

http://www.boyleworks.com/ta400/psp/compression.html

[KiddX]

what kind of gain are expected from these herre pistons? i might strap some in!

[JesseSays]

Originally posted by KiddX
what kind of gain are expected from these herre pistons? i might strap some in!

not a ton, maybe 5 hp throughout the entire powerband.


As I've said before, engines are a combination of 1000s of things. 1 will not make the entire system totally different. When you start combining optimized pieces all over the place, that's when you see real gains.

[WTF]

lower compression pistons

I know its an old thread but can help the nonsense and pure BS Jessy says brings up about higher compression in a turbo combo...

Its obvious you have never worked with turbo cars, the kind of nonsense you are bringin up is so damn ridiculous.

If some good free advice Spoolin Pro will have is:

Dude, get the Protege DX SOHC pistons especially from an automatic, the gains in power with a turbo is so stupidly insane!!! 100% gaurantee, NO BS.

I did this combo with a BP05 turbo, took out the stock pistons and put in the DX pistons in a BP05 turbo, DUDE, maybe you would feel a little lag, BUT once that turbo spool up, you better have a good clutch and performance tires cause you are gonna be eatin the road. When I swtiched from stock BP05 pistons to the DX SOHC I gained around 30 HP easy. I assume you have 2.25 of exhaust or more, good muffler, and a fuel pump to back up all this air.

Remember low compression makes more space for AIR, HEEELLOOOO!

Have you ever seen the low stock compression pistons of a Turbo targa Supra, you can drink beer in one of those. The car would be humble and peaceful at low rpms but once you know how to spool up that rubo the road is yours.



HELLO!?

MAYDAY!!!!

[91ProtegeLX]

LOL 30hp huh???

Ever seen those Champ cars, some of em run like 14:1 compression turbo v8s.

Jesse is 100% right in his posts. Most people run low compression pistons because its safer and has a less chance of detonating. Plus 100+ octane gas isnt cheap.

What is the BP05 turbo??? LOL.....and arent the sohc pistons higher comp than the dohc pistons? Hmmm maybe jesse was right.....

[charles]

I'm going to start deleting stupid posts in my sections