CR suggestions for turbo E85
Most junkyard 5.3's are 9.9:1 CR and people have been boosting them for years with varying levels of success depending on health of engine, build choices, and competency at tuning. There are plenty of vendors / sponsors to lean on who can give you advice because they have been spec'ing and selling turbos, cams, converters, standalone EFI, and more to people running 9's, 8's, and 7's with LS setups.
They often have experience with such cars themselves. Give them a call and start narrowing the focus of your build.
They often have experience with such cars themselves. Give them a call and start narrowing the focus of your build.
6.0 rod and piston ly6 9:3:1 compression s480 E85 makes 11 lb of boost on the brake in 2.8 seconds. 9.80 on wastegate (13lb) in a 3600 lb car on foot brake. A properly set up hotside is more important than compression for spool. And unless you live under a rock any ls with any compression will make power lol
9.5 - 10.5 static on a street car sounds about right.
Do yourself a favor and google the topic. There are several articles and videos reference the subject that provide a good explanation of the effects of increasing static compression ratio vs. boost pressure. More static compression is not always a good thing.
Do yourself a favor and google the topic. There are several articles and videos reference the subject that provide a good explanation of the effects of increasing static compression ratio vs. boost pressure. More static compression is not always a good thing.
At 9.5:1 on a street car, why not just use 93 on a street tune where you won't be able to use any more than 600-700hp to the tire anyway, then when you get to the track just use the race gas for 1000+ hp?
30% less fuel requirement than E85, and obviously 93 is more plentiful.
I can see that for a dedicated track can E85 has obvious benefits but for a street car that can't utilize the full hp output of the boosted engine, why not lower the compression and just run 93 on the street? You'd still be at a nice safe low boost level and have all the power you would ever need on the street.
Even though I like cubic inches and compression I don’t think there is any argument that could be made in favor of an NA setup over a boosted setup especially in a daily driveable car.
Obviously turbos have more power potential than any other combo. Prochargers have the advantage of no lag linear predictable power with no need to build boost before fully staging, but they also make less torque and have less power potential in comparable combos. The only hope for nitrous is to out 60’ you and have more cubic inches and/or be lighter. With street racing turning more and more to 1/8th mile that has kept nitrous in the game.
My local track is 1/8th mile it’s actually more fun because it’s just not a top end game. It’s also under Ihra rules which I believe requires a cage under 6.5 and I was already close to that with the 346 on 14 psi so now with the 377 and 16 psi I’m probably going to get the boot after my first good pass and don’t want to turn the gto into a race car so the procharger makes all the power I need in this car and isn’t maxed yet. It’s all about personal goals, likes, and budget. I like all combos, but obviously for low budget guys that want to go as fast as possible the junk yard turbo makes sense it’s just not my thing.
Obviously turbos have more power potential than any other combo. Prochargers have the advantage of no lag linear predictable power with no need to build boost before fully staging, but they also make less torque and have less power potential in comparable combos. The only hope for nitrous is to out 60’ you and have more cubic inches and/or be lighter. With street racing turning more and more to 1/8th mile that has kept nitrous in the game.
My local track is 1/8th mile it’s actually more fun because it’s just not a top end game. It’s also under Ihra rules which I believe requires a cage under 6.5 and I was already close to that with the 346 on 14 psi so now with the 377 and 16 psi I’m probably going to get the boot after my first good pass and don’t want to turn the gto into a race car so the procharger makes all the power I need in this car and isn’t maxed yet. It’s all about personal goals, likes, and budget. I like all combos, but obviously for low budget guys that want to go as fast as possible the junk yard turbo makes sense it’s just not my thing.
Even though I like cubic inches and compression I don’t think there is any argument that could be made in favor of an NA setup over a boosted setup especially in a daily driveable car.
Obviously turbos have more power potential than any other combo. Prochargers have the advantage of no lag linear predictable power with no need to build boost before fully staging, but they also make less torque and have less power potential in comparable combos. The only hope for nitrous is to out 60’ you and have more cubic inches and/or be lighter. With street racing turning more and more to 1/8th mile that has kept nitrous in the game.
My local track is 1/8th mile it’s actually more fun because it’s just not a top end game. It’s also under Ihra rules which I believe requires a cage under 6.5 and I was already close to that with the 346 on 14 psi so now with the 377 and 16 psi I’m probably going to get the boot after my first good pass and don’t want to turn the gto into a race car so the procharger makes all the power I need in this car and isn’t maxed yet. It’s all about personal goals, likes, and budget. I like all combos, but obviously for low budget guys that want to go as fast as possible the junk yard turbo makes sense it’s just not my thing.
Obviously turbos have more power potential than any other combo. Prochargers have the advantage of no lag linear predictable power with no need to build boost before fully staging, but they also make less torque and have less power potential in comparable combos. The only hope for nitrous is to out 60’ you and have more cubic inches and/or be lighter. With street racing turning more and more to 1/8th mile that has kept nitrous in the game.
My local track is 1/8th mile it’s actually more fun because it’s just not a top end game. It’s also under Ihra rules which I believe requires a cage under 6.5 and I was already close to that with the 346 on 14 psi so now with the 377 and 16 psi I’m probably going to get the boot after my first good pass and don’t want to turn the gto into a race car so the procharger makes all the power I need in this car and isn’t maxed yet. It’s all about personal goals, likes, and budget. I like all combos, but obviously for low budget guys that want to go as fast as possible the junk yard turbo makes sense it’s just not my thing.
- "You just dont understand the instant power, big NA power is just a different driving experience man."
- "Boost is too laggy".
- "Boost is too complex and stuff breaks all the time".
- "I don't want to hack up my car".
- "Boost is too expensive".
- "Boost is useless unless you want more than 1000whp".
- "I don't want to run race gas".
Last edited by ddnspider; May 12, 2020 at 12:26 PM.
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Verdad Gallardo Yes that was after I swapped in a TH400 and started running E85 for higher boost levels. With the TH400 and a REALLY tight converter that I wanted since I drove it on the street more than anything it still didn't have a problem spooling at all. With a converter meant more for track use dare I say I could have probably foot braked it and not even needed a trans brake.
as it could be when just driving NA on the street? Or do I have this wrong?
Yes that was after I swapped in a TH400 and started running E85 for higher boost levels. With the TH400 and a REALLY tight converter that I wanted since I drove it on the street more than anything it still didn't have a problem spooling at all. With a converter meant more for track use dare I say I could have probably foot braked it and not even needed a trans brake.
Launching!
Joined: Jun 2012
Posts: 249
Likes: 36
From: Pennsylvania
Here is another one... I built this motor back in 2005 before E85 was really even a thing and it was intended for pump gas only, was 8.5:1 compression stock cubic inch LS1 with an old school 76GTS turbo that made full boost at 3800 rpms through a manual trans which is pretty damn early. Spooled great, made good power at ~15 psi on 91 octane. Then E85 came about and I started running it in this LOW compression setup, ran a best of an 8.96 @ 152.4 mph in 6000 FT DA maxing out that little 76GTS @ 18 psi of boost. Spooling has almost nothing to do with static compression and everything to do with the full combo including a properly setup hotside.
this is exactly what I did. I Based the motor on pump gas then e85 pumps started popping up everywhere so why not switch? I put in a trans break over winter so it will be a whole different ball game. You hit the nail on the head and was exactly the point I was making also!
Wasn't bad at all, don't get me wrong I wasn't going to make a 1000 mile road trip that's for sure but normal driving around town wasn't bad. I was running a 28" tire and 3.42s but could have stepped it down on the gearing with a looser converter. I was running a custom Neal Chance converter, wasn't exactly rated at any particular stall speed but foot braking it would only get up to around 2800 rpms before pushing through the brakes if I remember correctly and on the transbrake it would go as high as I needed.
Another twist on the TH400 setup. Basically gear it like a glide with OD. I run a 2.73 and 27" tire. It will do roughly 140 in 2nd gear. Basically geared like a 4.10 at 1:1 in 3rd gear. Then I only use 3rd for overdrive cruising the streets. WIth snappy small twins it makes for a fun 4.8 street car.
I have a pretty tough TH400 and I'm only making 600-700ish whp I'd guess. But so far it's a great setup. Not sure how well 2nd gear will hold up. Car is relatively light as well. 3050 with me in it. I dont' launch it hard at the track either... Would probably munch the 2.73's with a hard launch.
I have a pretty tough TH400 and I'm only making 600-700ish whp I'd guess. But so far it's a great setup. Not sure how well 2nd gear will hold up. Car is relatively light as well. 3050 with me in it. I dont' launch it hard at the track either... Would probably munch the 2.73's with a hard launch.
Th400 Another twist on the TH400 setup. Basically gear it like a glide with OD. I run a 2.73 and 27" tire. It will do roughly 140 in 2nd gear. Basically geared like a 4.10 at 1:1 in 3rd gear. Then I only use 3rd for overdrive cruising the streets. WIth snappy small twins it makes for a fun 4.8 street car.
I have a pretty tough TH400 and I'm only making 600-700ish whp I'd guess. But so far it's a great setup. Not sure how well 2nd gear will hold up. Car is relatively light as well. 3050 with me in it. I dont' launch it hard at the track either... Would probably munch the 2.73's with a hard launch.
I have a pretty tough TH400 and I'm only making 600-700ish whp I'd guess. But so far it's a great setup. Not sure how well 2nd gear will hold up. Car is relatively light as well. 3050 with me in it. I dont' launch it hard at the track either... Would probably munch the 2.73's with a hard launch.