single gt35 on stock ls1?
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From: green bay wi
single gt35 on stock ls1? my friend is taking this off of his 2.0 mitsu that made 630 hp with no juice. so i want to do a diy kit and use it. i am looking for 500 to 550 whp. oh yeah i believe the ar on the turbine housing is .86.
sounds to small,
exhaust gas velocity
http://www.forcedinductions.com/consumption346.htm
compressor map
http://www.forcedinductions.com/GTseries.htm
exhaust gas velocity
http://www.forcedinductions.com/consumption346.htm
compressor map
http://www.forcedinductions.com/GTseries.htm
Originally Posted by 2000zrocks
600 hp worth of airflow is 600hp worth of airflow regardless of how many cyl. make it.
its more one the exaust part of things witht that turbo as stated before it will choke out to soon. BUt the incoming air you have to deal with pressure ratios a bigger motor will have a lower pressure ratio, a smaller motor a higher pressure ratio. The turbo charger will make more power at the higher pressure ratio per CFM output because it is in a better part of its effeincy range (it will pump out more air and cooler air where if you tried to get the required CFM at a lower pressure ratio it will pump out hotter air or not as much in that part of the map. This depends on how the turbochargers flow map is. If you look on a compressor map you will see the regions with effiency ratings on it from 50%-80% the better the effeincy the more power you will make.
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The PR/Flow point on a 2.0L is no where near what it will be on a 5.7L engine.
Even a big 35 will be outta steam by the torque peak at the boost level you mentioned.
Find a compressor map for that turbo and have a look.
Unless your getting it for free, don't waste your time.
Even a big 35 will be outta steam by the torque peak at the boost level you mentioned.
Find a compressor map for that turbo and have a look.
Unless your getting it for free, don't waste your time.
Originally Posted by 2000zrocks
well i guess we will see then. i think a gt35 at 9psi will make 500 whp.
You come to a board with some of the best Fbody minds in the whole world & ask them a question they give you the answer & you don't wanna believe what they say. All I can is say is get a Pyrometer cause with that exhaust restriction your gonna have you are bound to melt something down.
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From: green bay wi
Originally Posted by jamnut
You come to a board with some of the best Fbody minds in the whole world & ask them a question they give you the answer & you don't wanna believe what they say. All I can is say is get a Pyrometer cause with that exhaust restriction your gonna have you are bound to melt something down.
with that i agree that the gt35 at 9lbs is right of the optimal effiecency range for 50 or so lbs a min. so is a gt42. turbos are also tuneable, i can go to a 1.06 ar on the exhaust housing. is any of this ideal no but i want to see how it will work because i can get the turbo for a good price.
Red line is 9 psi, assuming constant pressure over all RPM.
pressure ratio should be closer to 1.6, but i SWAG'd the compressor efficiency since you'll be way off anyway. Density ratio is probably killing it.
You're beyond the choke line of the turbo by 4K RPM, not just off the center island.
you'll make 9psi until peak torque, and the boost will drop like a stone. running out of the compressor's efficiency and choking the compressor are not the same.
Not to mention you'll put so much heat into the air you'll have to take a ton of advance out, or drown it in fuel to keep the motor happy.
I'm just tossing in my .02
pressure ratio should be closer to 1.6, but i SWAG'd the compressor efficiency since you'll be way off anyway. Density ratio is probably killing it.
You're beyond the choke line of the turbo by 4K RPM, not just off the center island.
you'll make 9psi until peak torque, and the boost will drop like a stone. running out of the compressor's efficiency and choking the compressor are not the same.
Not to mention you'll put so much heat into the air you'll have to take a ton of advance out, or drown it in fuel to keep the motor happy.
I'm just tossing in my .02
Last edited by y2khawk; Nov 1, 2005 at 02:03 AM.
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From: green bay wi
alright heres what i think i understand: gt35(i for got to mention that this turbo was custom built by agp turbo and is not an off the shelf gt35) at 35psi car making 600 hp worth of exhaust the pressure ratio is more correct than it would be for a ls1 car making same hp at say 10lbs. should be roughly same amount of exhaust volume. im gonna say that i believe that the 2.0 mitsu i mentioned before is more efficient than my stock ls1 so yes it would flow less exhaust at the same hp than my car. i do not believe that this turbo would choke off the exhaust as some of you believe.
if what im saying is way off please dont come off of your pedastool to scold me. if you would like to discuss why or whynot this is correct or not please help me.
i love how the one guy who seems to know about turbos or have one on his car gave me solid advice and info to back it up was nice about it. everyone else just got offended that someone might choose to experiment a bit instead of bow down the the techmasters of the universe.
if what im saying is way off please dont come off of your pedastool to scold me. if you would like to discuss why or whynot this is correct or not please help me.
i love how the one guy who seems to know about turbos or have one on his car gave me solid advice and info to back it up was nice about it. everyone else just got offended that someone might choose to experiment a bit instead of bow down the the techmasters of the universe.
we are just trying to keep you from wasting your money and save your car from damage. take my first post, plot your PR per air flow liike harlan did and youll find out your way out of range on the map.
most people who posted in here know of this but havent took the time to expalin it fully, , i dont know you just seem hard to convince. good luck i guess, hope it dont damage to many stuff
most people who posted in here know of this but havent took the time to expalin it fully, , i dont know you just seem hard to convince. good luck i guess, hope it dont damage to many stuff
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From: green bay wi
just for kicks, go back and look at that compressor map for the gt35, and tell me how much boost a mitsu 2.0 needed to make 630 whp with that turbo. no nitrous. this has nothing to do with my original questions only make some of you guys realize that what it says on paper isnt always best or right.
assuming he spun it beyond 9k RPM?
I'd say north of 30 to 35 psi, and that's just starting to work that turbo. A 35 likes the high pressure ratio of a small motor.
Hell, the 67mm wheel in the GT40 on my truck won't hold 12 psi much beyond 6k RPM in third gear. And that's a stock displacement LS1 with box stock 5.3L heads.
121 cu in with lots of RPM is no comparison to 346 cu in a low RPM.
The old incons were a 35mm wheel'd gt25R's and i couldn't hold much more than 15psi with them on a heads/cam motor. 700rwhp was about the limit. And we had 2 of them.
Honestly, it seems like your hung up on the peak flow numbers. Those don't mean much if your motor/turbo combo will never get there.
I'd say north of 30 to 35 psi, and that's just starting to work that turbo. A 35 likes the high pressure ratio of a small motor.
Hell, the 67mm wheel in the GT40 on my truck won't hold 12 psi much beyond 6k RPM in third gear. And that's a stock displacement LS1 with box stock 5.3L heads.
121 cu in with lots of RPM is no comparison to 346 cu in a low RPM.
The old incons were a 35mm wheel'd gt25R's and i couldn't hold much more than 15psi with them on a heads/cam motor. 700rwhp was about the limit. And we had 2 of them.
Honestly, it seems like your hung up on the peak flow numbers. Those don't mean much if your motor/turbo combo will never get there.
Originally Posted by y2khawk
Honestly, it seems like your hung up on the peak flow numbers. Those don't mean much if your motor/turbo combo will never get there.
For the guys that are still looking to understand more....check the link below.
Turbo Tech help
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From: green bay wi
man you guys are full of yourselves. right away you gotta talk to my like im a dumb kid.
notice how at 35 psi a pr of something like 3.4 its to the north of the map. thats all im getting at. if you were going to choose a turbo for this application from the map would this be it? probably not but it works. how much heat do you think is generated by a turbo still not in the eff. range at 35psi versus 9. I AM NOT TRYING TO CONVIENCE YOU.
also 2 things 1 i seem to remember a turbo kit a few years ago for either the ls1 or the lt1 (i cant remember) that came with a 60-1 which is real close to the gt35. i saw this in gmhp. 2 go to turbofast.com.au and go to calculators go to turbo match enter 5700cc, 8lbs, max rpm 6000, intercooled and 1 turbo. it recomends a gt30. with airflow ppm at 53 with bhp at 580. interesting. im not taking this as im right your wrong, so dont get all defensive. am i stuck on peak flow numbers?
notice how at 35 psi a pr of something like 3.4 its to the north of the map. thats all im getting at. if you were going to choose a turbo for this application from the map would this be it? probably not but it works. how much heat do you think is generated by a turbo still not in the eff. range at 35psi versus 9. I AM NOT TRYING TO CONVIENCE YOU.
also 2 things 1 i seem to remember a turbo kit a few years ago for either the ls1 or the lt1 (i cant remember) that came with a 60-1 which is real close to the gt35. i saw this in gmhp. 2 go to turbofast.com.au and go to calculators go to turbo match enter 5700cc, 8lbs, max rpm 6000, intercooled and 1 turbo. it recomends a gt30. with airflow ppm at 53 with bhp at 580. interesting. im not taking this as im right your wrong, so dont get all defensive. am i stuck on peak flow numbers?
Dude, you came on here asking a question, and refuse to accept the answers that you are getting because you don't agree with them. Harlan (y2khawk) and Jose (JZ 97 SS 1500) are probably the two most knowledgable FI people on this board. As far as I'm concerned, their words are gospel. If it relates to FI, these guys know their ****.
What "should" work and what "does" work are often two totally different things.
Shawn
What "should" work and what "does" work are often two totally different things.
Shawn