Testing The Waters

[Jason@DSG]

I have 9.0:1 @ 30psi with boost on at 3,050rpm making 500whp in daily driver.

I'm also not saying everyone has to run 9.0:1 here, I was using that as an example. But 12.5 is way too high to make safe power is the point. 10.5 would be good IMO, 9 for very high boost.

The pistons are customizable in both diameter as compression. I'm just trying to prove a point that high compression with a boosted engine on pump gas is a recipe for disaster. Trust me, I've built many engines for this reason over the years.

So to stop the back and forth:

CP and JE pistons are now available to run lower than stock compression and with the addition of also available Darton Sleeves, up to 90mm possible

Forged rods from BC available in both I as H beam

Lowering the compression will allow safer and higher boost as the OEM compression at 12.5 doesn't have much room to play with

[diss7]

Originally Posted by Jason@DSG

I have 9.0:1 @ 30psi with boost on at 3,050rpm making 500whp in daily driver.

I'm also not saying everyone has to run 9.0:1 here, I was using that as an example. But 12.5 is way too high to make safe power is the point. 10.5 would be good IMO, 9 for very high boost.

The pistons are customizable in both diameter as compression. I'm just trying to prove a point that high compression with a boosted engine on pump gas is a recipe for disaster. Trust me, I've built many engines for this reason over the years.

So to stop the back and forth:

CP and JE pistons are now available to run lower than stock compression and with the addition of also available Darton Sleeves, up to 90mm possible

Forged rods from BC available in both I as H beam

Lowering the compression will allow safer and higher boost as the OEM compression at 12.5 doesn't have much room to play with

Also making a point of mentioning that lower compression effect response, driveability, spool, and you'll need more boost to make the same power.

[Jason@DSG]

Originally Posted by diss7

Settle down guy.

No one is saying 12.5CR is okay for crazy power.

9.0CR is ideal if running CRAZY boost, for CRAZY power. Like the examples you have listed above. But is this really your target audience? No of course not. Anyone with pockets that deep isn't getting off the shelf parts.

Your target market just selling pistions and rods is to people trying to get a built motor on the cheap. Maybe 400 - 500whp. They're not R35 owners, or 1600whp owners.

Set whatever CR you want, its your business. Just don't expect to put out information on a public forum, then get butt hurt when you get differing opinions.

Not butt hurt bud, just don't want people chiming in with opinions that can mislead other people.

I even clarified in my original post that I was using those compression and boost levels as theoretical and as reference.

I don't recommend 9.0:1 on this car (unless for a high hp/high boost application). I think 10 or 10.5 would be good and allow the boost to be ramped up/not affect drivability or spool

The only good thing about maybe going lower is keeping the option open to big after and only suffering a bit of lag when not in boost in the meantime

Good luck to all, no hard feelings! Just want to get the info out and make sure guys who may not know, make the right decision with proper info

Cheers!
J

[diss7]

My (and others) intention was not to mislead anyone. Opposite infact. We were putting out the information about the negative aspects of the trade off that is lowering your static compression.

I still dont like the "I think this is ideal and it won't affect driveability" They're generic comments.

Lowering the comp a little bit, will affect things a little. Lowering it a lot, will affect them a lot.

Edit - although I actually agree that 10.5CR would be a good starting point for a 400whp FA20 build on pump. But it may turn out that it could've been 11.0, or 11.5. Only time will tell, via trial and error.

[Jason@DSG]

10.5 on a boosted application won't make a huge difference in drivability, especially with a smaller quick spooling turbo.

9.0 would make a difference yes, it would drive like my car laggy at 2000, but I have a medium sized turbo and spools very quickly (it's also ported with a 3" non anti-lag inlet to really emphasize spool). So I barely notice anyway.

[FreshFRS]

Originally Posted by diss7

My (and others) intention was not to mislead anyone. Opposite infact. We were putting out the information about the negative aspects of the trade off that is lowering your static compression.

I still dont like the "I think this is ideal and it won't affect driveability" They're generic comments.

Lowering the comp a little bit, will affect things a little. Lowering it a lot, will affect them a lot.

this was exactly my intention.

[diss7]

Originally Posted by Jason@DSG

10.5 on a boosted application won't make a huge difference in drivability, especially with a smaller quick spooling turbo.

9.0 would make a difference yes, it would drive like my car laggy at 2000, but I have a medium sized turbo and spools very quickly (it's also ported with a 3" non anti-lag inlet to really emphasize spool). So I barely notice anyway.

Yes, but you're missing the point. Saying it will make no difference, and saying it wont make a huge difference are two different things.

Also, seeing as you have changed your mind about what CR is ideal, you should edit Post 7.

[Jason@DSG]

Originally Posted by FreshFRS

this was exactly my intention.

Same here. I was just putting an explanation out there to those who may not know about the effects of lower lowering compression for a boosted application, especially on a non-factory turbocharged engine.

I appreciate everyone's input, I think we got off track and we're working together for the greater good of the info on here. One of those we're all saying the same thing in a different way lol

Sorry if things seemed overly direct, wasn't my intention. Hopefully everyone can take away good info from here as some bigger power builds start happening!

[Jason@DSG]

Originally Posted by diss7

Yes, but you're missing the point. Saying it will make no difference, and saying it wont make a huge difference are two different things.

Also, seeing as you have changed your mind about what CR is ideal, you should edit Post 7.

Good call, I added for big boost applications. Thanks for spotting that

[diss7]

Originally Posted by Jason@DSG

Same here. I was just putting an explanation out there to those who may not know about the effects of lower lowering compression for a boosted application, especially on a non-factory turbocharged engine.

I appreciate everyone's input, I think we got off track and we're working together for the greater good of the info on here. One of those we're all saying the same thing in a different way lol

Sorry if things seemed overly direct, wasn't my intention. Hopefully everyone can take away good info from here as some bigger power builds start happening!

Admitidly, I get a bit defensive when I feel that someone is leaving out information that could be seen negaitively, and only focusing on the positives. Particularly when this is a vendor.

But agree, no hard feelings at all. Just trying to keep all points discussed.

[FreshFRS]

Originally Posted by Jason@DSG

Same here. I was just putting an explanation out there to those who may not know about the effects of lower lowering compression for a boosted application, especially on a non-factory turbocharged engine.

I appreciate everyone's input, I think we got off track and we're working together for the greater good of the info on here. One of those we're all saying the same thing in a different way lol

Sorry if things seemed overly direct, wasn't my intention. Hopefully everyone can take away good info from here as some bigger power builds start happening!

nah no worries everything sorted itself, and hey directness is usually the best way to get things across on the interwebs.

[Jason@DSG]

Originally Posted by diss7

Admitidly, I get a bit defensive when I feel that someone is leaving out information that could be seen negaitively, and only focusing on the positives. Particularly when this is a vendor.

But agree, no hard feelings at all. Just trying to keep all points discussed.

Originally Posted by FreshFRS

nah no worries everything sorted itself, and hey directness is usually the best way to get things across on the interwebs.

I appreciate it very much! Always good to get the info out, I think I missed out a few things but we definitely went over it here. I'll take care of revising my first post on here to recap everything we talked about for easier access. I'm sure very few people will get passed page 2 unfortunately haha

Cheers guys, thanks for the valuable input @diss7 @FreshFRS

[diss7]

Originally Posted by FreshFRS

nah no worries everything sorted itself, and hey directness is usually the best way to get things across on the interwebs.

Thats why porn sites do so well.

[FreshFRS]

Originally Posted by diss7

Thats why porn sites do so well.

Aint that the truth!