how to lower 9:1 compression

[Turbo Talon DL]

Like I said, on pump gas you can run more boost with lower compression so it all depends on the efficiency of the turbo. Who wants to make big power on pump though?

Who would NOT want to be able to make big power on pump gas? Guess there's something wrong with maximizing whats easily and readily available, like pump gas. I dont want to have lets say a 450hp tune on 110 octane race fuel and only be able to make 360hp or so on pump. I want to be able to make 400hp on PUMP........

 

[MNGSX]

Convert to E85 and you could make over 600hp with the right turbo. You would also do it on fuel that costs on average .50cents less than regular..

Also depending on the boost you want to run you might want to leave it at 9:1 for this stuff..

 

[95AWDTALIPS]

Convert to E85 and you could make over 600hp with the right turbo. You would also do it on fuel that costs on average .50cents less than regular..

Also depending on the boost you want to run you might want to leave it at 9:1 for this stuff..

Sorry if this sounds kind of a dumb question but what is E85 exactly?

 

[MNGSX]

85% Ethanol Alcohol
15% Gasoline

 

[1fast97gsx]

Who would NOT want to be able to make big power on pump gas? Guess there's something wrong with maximizing whats easily and readily available, like pump gas. I dont want to have lets say a 450hp tune on 110 octane race fuel and only be able to make 360hp or so on pump. I want to be able to make 400hp on PUMP........

Um ok ... but then why put a built motor in a car? A stock longblock with a 50 trim or larger can make 400 whp on pump. Now lets say for example you do "maximize" your pump setup and make 400 + whp. How much do you think you'll make on race gas then? Significantly more I'm sure and that's why the high boost comes into play.

 

[MNGSX]

Run CR about that of 1 stock 1g turbo but with a forged engine for the best pump gas performance...


I am kind of to questions about my motor for now but I can say from exp that stock 1g CR is not enough static compression for the higher% ethanol fuels but is really good for 87 octane.. On forged parts with more compression I can run ALOT of boost on the alcohol..

 

[definitiveno]

Run CR about that of 1 stock 1g turbo but with a forged engine for the best pump gas performance...


I am kind of to questions about my motor for now but I can say from exp that stock 1g CR is not enough static compression for the higher% ethanol fuels but is really good for 87 octane.. On forged parts with more compression I can run ALOT of boost on the alcohol..

Thats what I plan on doing. If the nearest E85 station wasn't 100 miles away I'd be all over the conversion. For now I am gonna try to get the best out of buscher's alcohol kit and a pump gas tune.


My car will never see a drop of race gas. But it's not crime for the people who use it.

 

[95AWDTALIPS]

Where do you find a E85 station? Is it basically one of the BP station's you find that sells high octane (100+) gas?

 

[95AWDTALIPS]

and if thats the case I have a BP station here like that.

 

[definitiveno]

http://www.e85fuel.com/e85101/flexfuelvehicles.php


Doesn't seem to be any stations in florida dude. There's only one in california right now too..

 

[95AWDTALIPS]

Oh well, the site you linked me to doesn't say dsm's are compatible anyway. Unless their's a way around that. It doesn't really matter anyway.

 

[definitiveno]

Oh well, the site you linked me to doesn't say dsm's are compatible anyway. Unless their's a way around that. It doesn't really matter anyway.

Convert to E85

You have to convert some things......

 

[SpoOLxExO]

Definitiveno is gunna love me for this.

BUT....

Here is what a 9.0:1 engine with 850cc injectors, pump fuel (93 from 7-eleven) and 21 psi boost pressure. Also only running a single walbro 255HP and damn near just about maxed out.

http://www.dsmtuners.com/forums/showthread.php?t=196341 (<---scroll to bottom)

This was on a 2.5l STi but the turbo in question is a GT40, so I can imagine that similar numbers at similar boost pressure can be attained. Even though you are through losing .5 l and gaining a larger turbo frame.

I personally think that great pump gas numbers can be done with 9.0:1. The intercooler, turbo and fuel efficiency are your biggest variables, so make sure all of them are up to snuff.

Althoug I have to agree with the thick HG suggestion as well if you are still a bit squeemish
about your compression.

Whew...and I'm spent.

 

[BlackHawkAWD91]

I run 9.1 Ross, tested compression is 190+-2 across. I can only run 17PSI on a 50trim with no knock, with meth/water injection i run 21Psi. Not sure on wheel Hp, but car ran 11.9@117. On my stock engine, tested compression was 145, running 25PSI the car ran best of 12.2@114.

Hope this helps in some way when thinking about 9.1 vrs 7.6.1

 

[MNGSX]

yes you can make decent power at 9:1 on premium pump but to pull a andre on the stuff you need to drop the compression to 8.5:1 and run a bit more boost.

To set a pump gas record I would go even lower on the CR and higher on the boost... Run a "race gas" pressure ratio turbo... GT35R at "race gas" boost levels via droping the compression into the 7's....

IMHO run around 9:1 the same boost and use E85 then flip OPEC the bird.....

 

[1fast97gsx]

I run 9.1 Ross, tested compression is 190+-2 across. I can only run 17PSI on a 50trim with no knock, with meth/water injection i run 21Psi. Not sure on wheel Hp, but car ran 11.9@117. On my stock engine, tested compression was 145, running 25PSI the car ran best of 12.2@114.

Hope this helps in some way when thinking about 9.1 vrs 7.6.1

You have something else wrong then. I was running 9:1 eagle wiseco on a 56 trim and 21 psi was easily attainable with 93 octane. With some tuning I was able to run 23 as well with no knock in any gears. What type of base timing are you running? Is the car tuned? I've seen people run 25+ psi with methanol injection on a setup like yours and bust out low 11s.... Maybe your fmic isn't up to par? Base timing is off? You have boost leaks? Poor tuning?

 

[MNGSX]

You can run more timing at slightly lower CR 8.5 but yes you can do that on a 56 trim... you can run much more boost and timing at a even lower CR...


If 20's # is ok for you on the street and you really only want to stretch its legs on 100+ octane at the strip it is a good setup...

I run buku timing and boost with my compression ratio on the alcohol...

 

[BlackHawkAWD91]

You have something else wrong then. Is the car tuned? I've seen people run 25+ psi with methanol injection on a setup like yours and bust out low 11s.... Maybe your fmic isn't up to par? Base timing is off? You have boost leaks? Poor tuning?

Haha, where to start. Base timing is 2-3. I have zero leaks, my egts dont get above 850cc. The car trapped 122 on a little 50trim with internal gate, im more then happy with that. There is more then a "couple" cars running slower times with much larger turbos, and a much smaller number of people running faster with the same or smaller turbo than I. Im 101% sure there is better tuned cars and better drivers than I, however I am far from thinking something is Wrong. I think you need to review dsmtimes.org

If low 11s are so easy to get with 50trims and 20gs, I question why we need the other 15+ turbo combo's that are larger and tuners still have hard time getting those easy low 11s you speak of.

Hahah. Happy Boostin!

 

[MNGSX]

I have'nt hit a track yet with this setup... Those local, national and family emergencies poping up... I did run against a friends V8 car on some blacktop between cornfields.. He has a best of 10.80 and more often consistent 11's.. I was considerably quicker.....

BlackHawk... Is right Its all about tuning..

Which is why I am probably going to a motec with a crank trigger..

 

[95AWDTALIPS]

My machine shop in town said that with a head gasket 0.080 thick I might be able to drop my compression from 9:1 to 8.5:1. If I were to run E85, what all would need to be replaced?

 

[MNGSX]

My machine shop in town said that with a head gasket 0.080 thick I might be able to drop my compression from 9:1 to 8.5:1. If I were to run E85, what all would need to be replaced?

Thread
http://www.dsmtuners.com/forums/showthread.php?t=168760&page=2&pp=25&highlight=E85

Best info
http://www.westbioenergy.org/reports/55019/55019_final.htm

 

[madmader]

BAH there is a resion N/A's and Turbo's run diffrent compresion pistons. It's called pre detonation......................

Higher boost the lower compresion ratio you want!

9:1 would knock like a Mother trucker with 30 lb's...

 

[suicidal2af]

BAH there is a resion N/A's and Turbo's run diffrent compresion pistons. It's called pre detonation......................

Higher boost the lower compresion ratio you want!

9:1 would knock like a Mother trucker with 30 lb's...

Actually, it's called preignition.

 

[1fast97gsx]

Haha, where to start. Base timing is 2-3. I have zero leaks, my egts dont get above 850cc. The car trapped 122 on a little 50trim with internal gate, im more then happy with that. There is more then a "couple" cars running slower times with much larger turbos, and a much smaller number of people running faster with the same or smaller turbo than I. Im 101% sure there is better tuned cars and better drivers than I, however I am far from thinking something is Wrong. I think you need to review dsmtimes.org

If low 11s are so easy to get with 50trims and 20gs, I question why we need the other 15+ turbo combo's that are larger and tuners still have hard time getting those easy low 11s you speak of.

Hahah. Happy Boostin!

Perhaps I was exagerating a little when I said low 11s are EASILY attainable, however it is very possible. A local member to me ( Mike johnson I believe ) ran an 11.50 @ 119 on pump gas on a 50 trim. Another kid I know ran a 12.8 on pump with a stock engine ( 2 low cylinders ) and a 56 trim on pump but he trapped at 118. The slow time is because he is fwd convert. with stock tires and no other suspension mods. Is there a reason you are only running 2-3 degrees base timing? I was able to get away with 5 degrees base on my 9:1 motor at 22 psi on 93 octane. I had no counts of knock and timing advance was perfect. I still think something is wrong if you can only get away with 17 psi on pump with your setup. A new pump record of around 530 whp was just set a few days ago by slowboy racing and they tuned the car around 26 psi if I remember right ... it may have been more. This was also on pump gas with no additional methanol / water injection. I'm assuming that 122 you speak of was done on race gas? At how much boost?

 

[madmader]

Actually, it's called preignition.

sorry but i think it is called Detonation. Where the compresion is to high.