12:1 compression/ High Boost / E85
12:1 compression/ High Boost / E85 Is anyone running a combo similar, this sort of a max effort combo. 6 Bolt LSX block, 427ci, 6-Bolt Trickflow 245s, Callie's Ultra Billet CCW, Mechanical Belt drive fuel pump. Boosted by a pair of twin Forced Inductions T4 ETR HO 80/87 Turbos. Just wondering if anyone is having luck with high compression and and high boost while on corn. (20-25lbs) I figure if I'm going to build a motor then why not try to wring the max hp out of it.....I'm running MS3pro and will have a VERY knowledgeable tuner behind the laptop along with logging EGT and doing individual cylinder tuning
TECH Enthusiast
Joined: Jan 2012
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From: Bowling Green KY
Typically you see these high compression, turbo builds for racing classes that limit turbo size, like to a 76mm inducer. The flow limit of the turbo is reached, so the only way to make more power is by making better use of the air it flows. Increasing compression improves efficiency, so that is where they tend to try to get an edge in power. I've talked to a guy racing in one of these classes in the pits last year, when I asked him about his setup, he shared with me he was running 13.5:1 static compression, and 23 psi. I was kind of shocked that he was that high of a level of compression, and that's when he explained why he was doing it.
Coltboostin is right on here, people building these types of combos are not going to share much, they are building them to win races.
Coltboostin is right on here, people building these types of combos are not going to share much, they are building them to win races.
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I'm sure you have a lot more experience than me when it comes to this type of build but a lot of people are doing very good on the corn.
TECH Addict
Joined: Jun 2002
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I'd run that on ignite 114 hell bump the compression up and run methanol and do it right.
If you are stuck on e85 which I definitely see reasons for it. I've ran e85 for few years and love it. Just buy a tester and watch the fuel you are throwing in the car.
If you are stuck on e85 which I definitely see reasons for it. I've ran e85 for few years and love it. Just buy a tester and watch the fuel you are throwing in the car.
Or you can run 10.5:1 and have some margin for street driving on e85 ....just a thought. But then again, you ask for opinions all the time, and then go the complete opposite of what people tell you.
FormerVendor
Joined: Aug 2014
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But its not Race Fuel. Once you get to a specific output, you will get zero warning you exceeded its capability.
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I don't exactly agree with John, but I will add some if's
If you're going to street drive and test n tune a lot and not be serious about racing and pump E is available in your area. drive on ethanol and race on methanol using to complete separate fuel systems. 12-13:1 will work like that. however you won't be driving it on pump gas. 11.5:1 to 12:1 with a camshaft that John or Brian normally would not recommend with a lot of overlap would allow you to drive out of boost (you'd have to really watch this) on pump gas.
the only time I have hurt an engine directly related to leaning out on E85 was when one of my secondary injectors didn't open (16 168# injector setup @74% duty cycle 36# boost 38# base fuel pressure pump E70 do the math how you like) and it REALLY burn a piston. I've had fuel pump relays go bad and cause 14-14.5 AFR WOT 7500+ rpm 30+ boost and not hurt anything. I know my junk made nearly 1400whp with 67mm twins and John's camshaft. switched to 72mm twins and the butt-o-meter and calculators (fuel consumption and mph pickup) says it picked atleast 150hp.......On pump E70
If you're going to street drive and test n tune a lot and not be serious about racing and pump E is available in your area. drive on ethanol and race on methanol using to complete separate fuel systems. 12-13:1 will work like that. however you won't be driving it on pump gas. 11.5:1 to 12:1 with a camshaft that John or Brian normally would not recommend with a lot of overlap would allow you to drive out of boost (you'd have to really watch this) on pump gas.
the only time I have hurt an engine directly related to leaning out on E85 was when one of my secondary injectors didn't open (16 168# injector setup @74% duty cycle 36# boost 38# base fuel pressure pump E70 do the math how you like) and it REALLY burn a piston. I've had fuel pump relays go bad and cause 14-14.5 AFR WOT 7500+ rpm 30+ boost and not hurt anything. I know my junk made nearly 1400whp with 67mm twins and John's camshaft. switched to 72mm twins and the butt-o-meter and calculators (fuel consumption and mph pickup) says it picked atleast 150hp.......On pump E70
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but Steve Smith is faster than me.....As are a few other turbo LS streetcars the most impressive are Steve's and Australian Terry Seng. Terry went a 7.3x recently @3300#, races on methanol and drives on corn, drag week type of car. He rode shotgun and tuned for Harry Haul in the Orange Chevelle on Drag Week 2016
i would agree with john about 'PUMP' E85 but....
with sealed ''C85'' fuel you are in a good position because you get the consistency and avoid surprises with a a bad patch of pump e85 specially if you are in a race... even if you run flex fuel sensor you wont get 100% from your combo because the patch you have was less ethanol content than what you want.
just my opinion
Good luck with the build
with sealed ''C85'' fuel you are in a good position because you get the consistency and avoid surprises with a a bad patch of pump e85 specially if you are in a race... even if you run flex fuel sensor you wont get 100% from your combo because the patch you have was less ethanol content than what you want.
just my opinion
Good luck with the build
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Joined: Dec 2004
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definitely the e85 is more forgiving, but if it's inconsistent, pop goes the weasel at that compression ratio on high boost
with that much compression, you run the chance of running low boost and getting outside the sweet spot of your turbos or making too much cyl pressure.
I think what John is saying is that compression ratio is "on the edge" and you are tuning as such and better be checking that fuel.
I like the idea, but don't be surprised when it rattles to death when the unexpected arrives
At super high cyl pressures, you are on the edge
with that much compression, you run the chance of running low boost and getting outside the sweet spot of your turbos or making too much cyl pressure.
I think what John is saying is that compression ratio is "on the edge" and you are tuning as such and better be checking that fuel.
I like the idea, but don't be surprised when it rattles to death when the unexpected arrives
At super high cyl pressures, you are on the edge
I was planning on only running 20-25lbs or so. Nothing much more than that. Our E85 has been awesome up here so far too. The specific gas station I go to, was dispensing E-92 out of the pumps.. consistently
still have been thinking about this, methanol has crossed my mind a few times... if I don't go methanol and run non intercooled then ill atleast have a really efficient intercooler while on e85 ( Chiseled IC4000).
If I bumped my compression up to 12:1, that puts me at 210psi CRANKING pressure and 10:1 DYNAMIC compression.. is there a rule of thumb with dynamic compression ? I ended up going with different turbos aswell. I now have Twin GTR Wheeled GT50-88mm's from Jose @ forced Inductions and went with a set of HIP'd Trickflow 245s prepped by Brian from BTR along with a pretty healthy Solid roller camshaft.
If I bumped my compression up to 12:1, that puts me at 210psi CRANKING pressure and 10:1 DYNAMIC compression.. is there a rule of thumb with dynamic compression ? I ended up going with different turbos aswell. I now have Twin GTR Wheeled GT50-88mm's from Jose @ forced Inductions and went with a set of HIP'd Trickflow 245s prepped by Brian from BTR along with a pretty healthy Solid roller camshaft.