Low compression pistons........please read - Boost Forum

Forum Post / Reply
You must log in before you can post or reply to messages.
Low compression pistons........please read
Friday, January 20, 2006 1:09 AM
I've been trying to order some low comp. pistons for my car (2.3L). I have the info. such as bore and stroke(+.040), comp. ratio, and ring info too, but who ever I call, they keep asking for the wrist pin location. If I don't have a piston to send to them or even let - alone a piston to measure, what the hell do I do?? Does anybody have this info.?, most likely not, but if you do, please let me know. This is the only thing that is preventing me from ordering. My orginal motor is still in the car and I don't have the time to pull the motor out( working stupid hours)...right now its 4:09am. That goes to show you where I'm at. Any help would be greatly appreciated.





T04B V-trim baby.....Time to Open a Can of Whoop A S S !!!

Re: Low compression pistons........please read
Friday, January 20, 2006 4:01 AM
1.240" from the top of the piston. pin size is .8661"



Gilles
2.3 Ho

Re: Low compression pistons........please read
Friday, January 20, 2006 7:07 AM
I have a friend selling a new set of JE 8.5:1 pistons for a 2.3. I don't have his email at work, but I will email you tonight with it




Jason
99 Z24

Racers Edge
Johnny Mack Turbo Systems
Engineered Performance
Re: Low compression pistons........please read
Friday, January 20, 2006 11:11 AM
Gilles & Jason, thanks a ton!!! Gilles, is that height for the stock piston or was that for a 8.5:1 piston, or does that matter???
Jason, I would be very interested in those pistons. Off hand, do you know if they are bored over .040"??? I'll be waitinf for that email address also.

Thanks again guys.





T04B V-trim baby.....Time to Open a Can of Whoop A S S !!!
Re: Low compression pistons........please read
Saturday, January 21, 2006 4:58 AM
It's stock height. It's all in the dish anyway. The side will still have the same height.



Gilles
2.3 Ho

Re: Low compression pistons........please read
Saturday, January 21, 2006 10:17 AM
Diesell wrote:I've been trying to order some low comp. pistons for my car (2.3L). I have the info. such as bore and stroke(+.040), comp. ratio, and ring info too, but who ever I call, they keep asking for the wrist pin location. If I don't have a piston to send to them or even let - alone a piston to measure, what the hell do I do?? Does anybody have this info.?, most likely not, but if you do, please let me know. This is the only thing that is preventing me from ordering. My orginal motor is still in the car and I don't have the time to pull the motor out( working stupid hours)...right now its 4:09am. That goes to show you where I'm at. Any help would be greatly appreciated.


I can get you any spec you want custom made if your interested.... about 1-2 years ago I got a set of 2.3 pistons made for Randy Wyn... 8.5;1 compression .020 or .040 overbore with valve pockets..... e mail me if your interested.







Re: Low compression pistons........please read
Saturday, January 21, 2006 12:32 PM
Diesell wrote:I've been trying to order some low comp. pistons for my car (2.3L). I have the info. such as bore and stroke(+.040), comp. ratio, and ring info too, but who ever I call, they keep asking for the wrist pin location.


I really wouldn't bother with lowering the compression unless you are planning some obscene amounts of boost.


sig not found
Re: Low compression pistons........please read
Saturday, January 21, 2006 12:41 PM
Quote:

I really wouldn't bother with lowering the compression unless you are planning some obscene amounts of boost.


my 2.3 is at 9.63:1 compression and people call me crazy to use a turbo with that compression. I know I love it when I get boost.



Gilles
2.3 Ho

Re: Low compression pistons........please read
Saturday, January 21, 2006 11:07 PM
Well as for the comp. ratio, its debatable. I was thinking of 8.75:1 or 8.5. I do plan on running around 15 to 20, but probably stay around 15. As for tuning wise, I will be using the megasquirt 2. But as for the comp. ratio, I see that there is no reason why I should'nt drop the comp. Not only will be a bit easier to tune than it would be with stock comp. , but it will allow me to make more power in the future if I decide to go with a bigger turbo setup. Thanks again guys, anymore info. will be much appreciated.





T04B V-trim baby.....Time to Open a Can of Whoop A S S !!!
Re: Low compression pistons........please read
Sunday, January 22, 2006 7:45 AM
If you want a sample to provide to a manufacturer,
Just go buy an aftermarket (not GM) stock replacement piston. They can be found for well under $30 US with some no name pistons even being only about $5.

As for the compression thoughts...

1st, no matter what a sticker says on a fuel door, all north american cars are designed to run on 87 octane fuel ----- this includes 2.3HOs @ 10:1 compression. Manufacturers cannot guarantee people will only use premium fuel, even if they tell them to, so they build in a a safety zone to keep from warrantying engines.
More than likely, you will be running premium, which is an added safety factor.

2nd, lower compression just kills efficiency.

3rd, lowering compression for forced induction, particulary to the 7.5/8.5 range, was a trend that began in the late seventies when cars were rare to see 9.0:1 in NA applications. Compare that to today where economy cars are running 10:1 and performance cars are running 11.25.
Its really just an obsolete concept.

4th, many companies are running high compression and FI. Lingenfelter, Roush, Salleen, Magnuson, vortech, paxton, GM, kenne-bell, turbonetics, greddy, etc, are all selling kits for 10:1+ engines and some are even give a warranty the engine.

5th, although I really hate the idea of referring to this, the 2 fastest Ecos on this forum are running ~17psi on stock cast 10:1 pistons.

6th, its a 2.3. It already has no low end torque. Lower compression will make that way worse.

That is all for now.



sig not found
Re: Low compression pistons........please read
Sunday, January 22, 2006 11:47 AM
So I wasn't crazy because I tough about 11:1 compression and boost on my quad.

My plan will change now. I gotta buy a set of rods and pistons.



Gilles
2.3 Ho


Re: Low compression pistons........please read
Sunday, January 22, 2006 5:25 PM
Well like I was saying earlier, I may go with either 8.75 or 8.5:1 ratio's and I'll probably end up with 8.75:1. Going from 9.5:1 stock to 8.75:1 (.75 dif), efficiency in this factor won't matter in any way,. there is always a sacrifice when trying to make power. But I know that in the future, I will be able to upgrade my turbo and setup with a lower comp. like 8.75:1 to develope power with the sake of a little more durability and safety than if I were to use a 10.1 or 11:1 ratio. Protomec has brought up very good points in every aspect and I know that he knows whats he is talking about and I still rely on his excellent info. I just feel that for tunability issues at first and at this point and time, that it will be a bit easier to tune with a lower compression. Thanks for the info. from everybody.
Todd, you had mentioned about getting some aftermarket pistons for pretty cheap. I know that if I try finding the same deals here, I will end up with a felpro piston costing a bunch, where abouts in detroit or surrounding areas do you think I can find some for cheap????





T04B V-trim baby.....Time to Open a Can of Whoop A S S !!!
Re: Low compression pistons........please read
Sunday, January 22, 2006 6:28 PM
Diesel,

I just talked to my buddy and he already sold the JE pistons. Sorry to take so long for a response

.


Jason
99 Z24

Racers Edge
Johnny Mack Turbo Systems
Engineered Performance
Re: Low compression pistons........please read
Sunday, January 22, 2006 6:29 PM
Thats alright, no problem. Thanks again.





T04B V-trim baby.....Time to Open a Can of Whoop A S S !!!
Re: Low compression pistons........please read
Monday, January 23, 2006 4:01 AM
A Fel-pro piston cost 30$ can. I have 4 right now in my 2.3.


Gilles
2.3 Ho

Re: Low compression pistons........please read
Friday, January 27, 2006 8:36 PM
I used to get flyers from all these really cheap engine parts companies all the time.
But unfortunately, I can't remember any of the names of those companies.

Since I can't provide the info I should easily have been able to provide...

I will offer to loan you an HO piston to use as a sample if need be.






2.3 Compression Height is 32mm.

If JBO email worked right, I would have answered this earlier.


sig not found
Re: Low compression pistons........please read
Wednesday, February 08, 2006 4:13 PM
MFK-223 said:
Quote:

1.240" from the top of the piston. pin size is .8661"


Protomec said:
Quote:

2.3 Compression Height is 32mm.


Just noticed this......32mm x .03937" = 1.25984

Which could it be?.........thats a .01984" difference roughly .020"





T04B V-trim baby.....Time to Open a Can of Whoop A S S !!!
Re: Low compression pistons........please read
Wednesday, February 08, 2006 7:40 PM
hum good one. I went with Fel-pro. that's what they gave for the 2.3 piston.



Gilles
2.3 Ho

Re: Low compression pistons........please read
Wednesday, February 08, 2006 9:43 PM
I am using 8.5:1 compression pistons in my set up, and my low end is strong as ever! I also have an alluminum flywheel, but honestly the drop in compression in our 4 cylenders is not very bad. Everyone here complains of no low end, but if you compare our torque curves to that of really any other 4 cylender on the market, even with 8.5:1 compression the quads and the LD9 win. The 2005 Acura RSX type S makes something around 210hp, but the torque is only 142lb feet, and that is at 6000 rpm, near our redline. Our motors make more than enough low end as far as I am concerned, and in a turbo application, the lower compression will allow for more boost from the turbocharger safer. Pre detination is kept to a minimum with lower compression, and the high end you will gain by dropping compression with the extra few psi will more than make up for a few lb/ft off the line.

I would not trade back my wiseco 8.5:1 pistons for anything higher, ever. My low end is still better than a '05 V6 tiburon, '03 SXT neon, 92 Z34 lumina, '05 RSX-S, and those are all 5 or 6 speeds. Thank you, goodnight.





22 miles per gallon and dropping fast...
Re: Low compression pistons........please read
Thursday, February 09, 2006 6:27 PM
I have a question, why do many people get caught up in how much boost they see on the gauge? I understand setting a target boost range to build a certain hp/tq level but don't these folks understand that what they see on the boost gauge is just a reflection of how effecient or ineffecient their engine is at flowing the air in and out!
Lets say you have a boosted engine and you see 15# on the boost gauge and the engine makes 375hp, now you port the head and it flows better and you add turbo friendly cams and now the boost gauge shows 10# of boos but the engine is making 500hp. What happened, you guessed it less restriction to the air/fuel moving into & out of the engine produces less boos but more power. Also the more boost you run the more heat is introduced into the air the less dense the air the less hp you'll make. That's why I don't adhere to lower compression and more boost I'd rather run 10.5:1 static and 15- 18 psi of boost than 8.5:1 and 30# of boost. Plus with higher static cr the engine is more responsive to throttle input before the boost kicks in.


2000 Z24 5spd header & catback for now.
Re: Low compression pistons........please read
Thursday, February 09, 2006 9:26 PM
Dale Young wrote:the more boost you run the more heat is introduced into the air the less dense the air the less hp you'll make. That's why I don't adhere to lower compression and more boost I'd rather run 10.5:1 static and 15- 18 psi of boost than 8.5:1 and 30# of boost. Plus with higher static cr the engine is more responsive to throttle input before the boost kicks in.


Well to begin with, the more boost you run DOES NOT dictate how much heat in introduced into the motor, TURBO SIZE and INTERCOOL EFFICIENCY have WAY more to do with the temps then boost pressure, smaller turbo's will be very hot at high boost, but why would you run high boost on a small turbo???

Next, where you think that 15-18psi with 10.5:1 compression will make more power then 25-30psi on 8.5:1 compression is beyond me. You need 3 things in an engine to make power, air, fuel, and spark. Assuming all other things are equal (which with a good set up, they are, or at least very close) you will make more power with lower compression. The magic of a turbo charger allows you to create identical combustion pressures with any type of piston, you want "X" combustion pressure, well on 10.5:1 it will take much less air and gas to get there, but on 8.5:1 it uses MUCH more air and gas, therefore giving you MUCH more power.





22 miles per gallon and dropping fast...

Forum Post / Reply
You must log in before you can post or reply to messages.

 

Start New Topic Advanced Search