Alright so I am in the process of building a 2.3 stroker and I am going to dable in the magical fuel e85. I'm building this car for hill climb and road course use so less boost with more timing and compression. I'm looking into running a divided t3 manifold and probably a turbo that has a efficiency range in the 30-40lb/min range but haven't decided which yet.

Now that the background is over I will get to the question. I'm looking to get the highest compression ratio on e85 as possible while running at most 30lbs of boost. I want the low end torque off the turbo with good turbo power. Now as some of you may know with road racing you don't want tons of boost hence why my max is going to be 30lbs. I have seen a lot of people running 10.5:1 comp ratio but could someone run around 11:1 or higher and still not have the probability of breaking parts. I understand with e85 you don't have knock but you still can break things. I have looked around in the search bar but cannot find things on this particular thought as most people run high boost with e85 but I'm looking to run higher timing and compression ratio. Any help would be great.

First what type of road racing as anything besides drag racing is lumped together by a lot of people.

Twisties, autoX, slalom, define the type of racing as they are all different and the set up is also different.

Where are you going to go hill climbing in Florida or will you be taken the car out of state?

I don't do much autox anymore but that's what my car used to be doing. I'm moving up to the faster stuff now. So to answer your question I'm going to be looking into the Touring or Super Touring class of SCCA. I will be traveling our of state for hill climb events as I do know there aren't any in Florida. I actually just moved here and have only been here a couple months but I came from the west where hill climb was much more prevalent and I had done a few events and got hooked immediately so I'm willing to travel to get to hill climb events.

kamikazeredneck said:

I understand with e85 you don't have knock but you still can break things.

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You're right about that.

Injector pin pushed out of the harness so the injector was only spraying about half the time....and then:

Ya this is exactly what I'm trying to avoid. I don't want to bend a rod, destroy a piston or break the crank. I'm looking to be able to have 600hp+ on e85 but will be probably running around 450-500 normally. I'm looking to make the motor overkill for what I'm planning on doing but with hill climb I want to have extra power available if needed. I know I'll be having the 2.3 with lower profile cams for lower torque performance. I want to make a torque monster more than huge peak hp.

Just remember: Piston speed is higher, side load is greater9rod angle) and it wont last quite as long. But youre not revving it to the moon so its probably about as reliable as any other boosted stroked motor. All comes down to the machine work and youre timing/afr/load

This is a nice quick read: http://www.dsmtuners.com/forums/art...stroker-destroker-long-rod-engine-basics.html

JusMX141 said:

Injector pin pushed out of the harness so the injector was only spraying about half the time....and then:

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You mean at the ECU? How the hell did the injector pin push out of the harness? Was this with AEM EMS?
Didn't they see the flashing "Danger To Manifold" message?? haha j/k

Damn that sucks...

kamikazeredneck said:

I don't do much autox anymore but that's what my car used to be doing. I'm moving up to the faster stuff now. So to answer your question I'm going to be looking into the Touring or Super Touring class of SCCA. I will be traveling our of state for hill climb events as I do know there aren't any in Florida. I actually just moved here and have only been here a couple months but I came from the west where hill climb was much more prevalent and I had done a few events and got hooked immediately so I'm willing to travel to get to hill climb events.

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That is what I thought, you are lucky as PBIR [morosso] host SCCA races, also at Homestead and Sebring, and at Homestead you could also race in FARA.

Do you have all your safety items already, remember the cage has to be SCCA specs.
Maybe I will see you at the track sometime.

Good luck.

boost97gst said:

Just remember: Piston speed is higher, side load is greater9rod angle) and it wont last quite as long. But youre not revving it to the moon so its probably about as reliable as any other boosted stroked motor. All comes down to the machine work and youre timing/afr/load

This is a nice quick read: http://www.dsmtuners.com/forums/art...stroker-destroker-long-rod-engine-basics.html

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I have read that page but thank you for the suggestion. I was just wondering if anyone had any experience with using higher than 10.5:1 compression ratios and maybe some suggestions on which pistons or what type of build I could go with (machining, head and bottom end) that would be optimal for this type of performance. I know even the smallest differences in the head machining, deck height and other things can change not only the compression but also the performance of the engine. Any suggestions in regard to all parts of the engine (bottom end, head porting, head parts, machining, etc) because I know there are others that have done similar things to their vehicles.

arrowhead said:

That is what I thought, you are lucky as PBIR [morosso] host SCCA races, also at Homestead and Sebring, and at Homestead you could also race in FARA.

Do you have all your safety items already, remember the cage has to be SCCA specs.
Maybe I will see you at the track sometime.

Good luck.

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Thanks man. My car is under the knife right now so I'm putting in a roll cage and ripping out everything DD related. Unfortunately the car is still in NM at the moment but I am buying my parts needed for the engine as I have 50k hard miles at 23psi of boost on my 6 bolt now so I'm getting some excess blow-by and am going to do the swap and rebuild while it's all apart. I'm going to make the car exceed all SCCA and NASA requirements so I can race in all events if I want.

I know Tyler from Force Engineering is/was running 11:1.

Im building a spare motor right now. Calculating, my final compression numbers, I'll be right around 11.3:1cr. I'm running their spec pistons with a 4g67/g4cn 42-43cc cylinder head.

lasthope05 said:

I know Tyler from Force Engineering is/was running 11:1.

Im building a spare motor right now. Calculating, my final compression numbers, I'll be right around 11.3:1cr. I'm running their spec pistons with a 4g67/g4cn 42-43cc cylinder head.

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Thanks that's great info! I would like to run around 11:1 or higher so knowing that others are running this high with their setup makes me think I can run something in that area without any big issues.

This car is not going to be a DD or anything so it might see 1000 miles a year but that's going to be hard miles. I'm expecting the engine to run great but I understand the engine isn't going to last 10 years or anything.

You can probably go as high as you want. Personally I'd go at about 11 to 1. fwiw methanol drag car stuff is in the area of 13to1 with a super inefficient roots blower and 30psi with a junk combustion chamber design.

If you were staying small turbo (16g) I'd be 12to1. But I'd also be getting good E85, not from a pump

Well it seems people aren't having much problem with 11:1. I would like to run around maybe 12:1 but don't want to bend a rod or shatter a piston. I's probably going to run a smaller turbo but I haven't gotten there yet and I was going to do some more research and if need be I can open another thread to discuss the turbo. Would the turbo size make that much difference to what compression I can run? I figured I had given all the pertinent information about my flow and boost levels but if more info is needed please let me know as I would like to give all information necessary to get a intelligent answer. Are there any engine builders or others that have first hand experience that could weigh in?

Thanks

Well it does depend on it some. Obviously the cylinder pressure from a maxed out 14b is going to be pretty small so you can run more compression than say a 35r. Without going into a whole book about it, it's hard to explain in any detail.

Also your turbo info is kinda misleading, I don't think there is any turbo out there that is going to only move 40lbs/min at 30psi on a 2.3

I apologize about being misleading. I will be looking at a turbo in the range of either the FP 71HTA or FP HTA DSM76. These two turbo's would be the best I believe for my setup. I will be figuring out more at a later time but right now those two are the one's I will be looking at when I get the motor finished. I hope that info will help with any estimates on a proper compression ratio.

rhys miller said his car runs 15:1 with e85. My engine has a calculate compression of 11.5:1. My friend engine has a calculate value of 12.7-13:1. My engine is a 2.0l. My friend engine is a 2.4l. I engine compression test 245psi and his compression test 265psi. I was able to make 568hp at 20psi with a 35r. My friend was able to make 630hp at 20psi with a 40r. I have 1000cc injectors that are max the heck out so I am stuck at 20psi up top. I spike it twice to 30psi around 5000-6000rpm and made almost 600tq with just 6 degree of timing. I blew up the ACT2600 street disc on the 2nd 30psi spike. My friend was able to make 730hp and 630tq at 28psi with the 40r with 8 degree of timing at peak power. If my engine ever blow up, I am doing want to do a 13:1 2.4l like his or even try the 15:1. The trick is to limit the amount of timing you are running. E85 will knock as observe on ecmlink log. We are running Aem which suck nuts at logging knock so we just go conservative with timing to be safe.


If you plan to run a 40psi or more, I think 8:1-9:1 is better since it will be able to hold more air and fuel for a bigger bang. If you want proven nastiness, you should try 12.7:1-13:1. Just make sure you have the bottom end that will be able to handle the tq if you are planning on doing the 2.3l.

What would be a good compression ratio if you don't want to run more than 35psi? I'm trying to decide on which compression to go with on a 2.3 build I'm gonna be doing.

To the OP: have you thought about e98? If the car is a track only or mostly vehicle you might be able to get 55 gallon barrels for a reasonable price. That way you don't get the huge inconsistency of pump e85 and the octane is near 120, if I remember correct, allowing more compression or just peace of mind. Just a thought...

Airsign89 said:

To the OP: have you thought about e98? If the car is a track only or mostly vehicle you might be able to get 55 gallon barrels for a reasonable price. That way you don't get the huge inconsistency of pump e85 and the octane is near 120, if I remember correct, allowing more compression or just peace of mind. Just a thought...

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I have thought about this but the rules of SCCA and NASA require me to be staying at no higher than e85. I will be making sure no matter where I get the fuel it'll be true e85 and not some lower variation. I probably won't be running stuff from the pump and will be trying to find a supplier to get true e85 as I will need drums so I can put it in the back of the truck when I go to the track.

I'm liking the fact that people are able to run as high as 15:1 compression even though that might be a little bit too high for my application. I will want to have reliability on the track pushing it for long periods of time because running that high of a comp ratio in a drag car isn't too hard but when you do 30min+ on a track at a time can be dangerous I would imagine. Maybe something around the 12:1 would be a good middle ground as far as torque and reliability are concerned. What would you recommend as a bottom end setup to handle maximum torque? What type of head setup are you running on your 11.5:1 setup? Great info guys!

BoostedK said:

What would be a good compression ratio if you don't want to run more than 35psi? I'm trying to decide on which compression to go with on a 2.3 build I'm gonna be doing.

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It might help if you gave the guys a little more info on your setup plans. I'm finding out that the more info you give allows others to give more accurate info for your particular setup.

Is pump E85 a bad idea to use then???

BoostedK said:

Is pump E85 a bad idea to use then???

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It's not that it is bad, it's the fact that e85 from the pump varies. During the summer you will probably get closer to true e85 but during the winter you could be seeing something more like e70 or less.

If you are going to be getting e85 from the pump then you will need to invest in a tester to make sure of your ethanol content. Also you should have your tuner make a few different tuning profiles so you can just open your laptop and change the tune for the correct ethanol content.

Another option is to get a GM fuel tester (I don't know the correct name for this so hopefully someone else with more knowledge can chime in). This tests the ethanol content in-line as the fuel goes into the engine. This then takes the reading and tells the computer what the content is and changes the tune automatically. This is a convenient setup for those who don't like keeping their laptop in their vehicle at all times to change tunes. I don't know if Link can do this yet but I believe AEM and other tuners can use the GM fuel testing unit.

Yea, not sure if link can interface with an on the fly tester. God that would be soooo nice if it did. I bought a little vial off ebay for testing. It seems accurate. Last time i got e85, about 7 weeks ago?, it was around e70 already. Even in the summer the best stations around here are not acutally e85. Makes tuning a little bit harder but if you fiddle with your globals thats all thats needed. 1 main correction. You would tell the ecu the injectors are bigger basically when running lower than actual e85.

Say your global for e85 is -65%. You test it and its actually e75, you may have to just take a guess at it and plug in -69% and see how that tracks on and off boost. Im ham handed with it, no math, just keep testing dif globals til i get it nailed and remember to keep going back to the same station so theres not much variation in actual ethanol content..

Goes without say, when running e85, a bottle of seafoam through every 3rd tank is not a bad idea. Some run a whole tank of 93 instead. I dont know if thats overkill.

boost97gst said:

Yea, not sure if link can interface with an on the fly tester. God that would be soooo nice if it did. I bought a little vial off ebay for testing. It seems accurate. Last time i got e85, about 7 weeks ago?, it was around e70 already. Even in the summer the best stations around here are not acutally e85. Makes tuning a little bit harder but if you fiddle with your globals thats all thats needed. 1 main correction. You would tell the ecu the injectors are bigger basically when running lower than actual e85.

Say your global for e85 is -65%. You test it and its actually e75, you may have to just take a guess at it and plug in -69% and see how that tracks on and off boost. Im ham handed with it, no math, just keep testing dif globals til i get it nailed and remember to keep going back to the same station so theres not much variation in actual ethanol content..

Goes without say, when running e85, a bottle of seafoam through every 3rd tank is not a bad idea. Some run a whole tank of 93 instead. I dont know if thats overkill.

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Ya I didn't think Link could interface with an on the fly tester but I wasn't 100% sure.

I have done the math before but I can't remember it off the top of my head at the moment. Usually the tuner can just change some values for you when you get your car tuned as it only takes them an extra couple min to do.

Ya I also recommend putting some sort of fuel system cleaner through but for those that have changed their pistons to only run e85 you can't run 91 so you have to take other methods. Usually every year you should get your injectors flow tested and clean out your lines really good. The biggest problem with e85 is that it gums up your fuel lines. I've had to change filters and even pumps because a buddy of mine running it let the car sit for 5 months with the tank full of e85 and the fuel went bad and then gummed up everything making things just fail when he tried to start it up. If you're going to run e85 then you need to make sure if you're going to store the car for extended periods of time you should drain the tank and make sure all lines are clear. Also you should always run something sort cleaner to clean out the lines every 3 or 4 tanks.

Ive got 3/4 tank of e85 in mine now. Need to drain it asap. Garage should be up in 2 weeks. Woohoo!
I couldnt imagine the sludge but since the only piece im keeping in the entire system is the pump i should be ok after cleaning it out with some pump gas.

Did not know that pistons like the wiseco hd 1400 were for e85 only. Thats news to me. I figured they labeled them e85 pistons because of the very high compression. Interesting. Wonder why one couldnt run pump gas with the "e85 pistons"? I mean, obviously you would have to decrease timing and a general tune for pump.

I see just making sure cause I've heard of people blowing up their blocks cause of the inconsistency of pump E85