better numbers with smaller turbo! 404ci + 76mm
12-26-2010, 07:10 PM
#1
better numbers with smaller turbo! 404ci + 76mm "What, he should be running an 88mm!" "oh theres no way a 76mm will work on that motor"
This is what everyone says to me at car meets and on the forum, but oh wait, it does work! I went from a turbonetics 78mm "hurricane" to a Precision 76mm GTS.
(NEW DYNO NUMBERS This is on a load bearing "dyno dynamics" dyno)
(OLD DYNO NUMBERS! non-load bearing dyno)
You might have seen my sticky on https://ls1tech.com/forums/forced-in...ifold-kit.html and in there I explained how i built this car to be A STREET CAR. not built for 1/4 mile times or to compete with, but to be a quick spooling street machine! I am sooooooo happy with how it turned out! On the same dyno it was previosly making 580ish rwhp and 650ish rwtq on about 13psi and now its set between 14-15psi, spools much quicker, pulls much harder, and is wayy more fun to drive!
yes an 88mm would pull better up top, but would also spool a lot slower and would be less fun for me on the street. ill prob take this to the track for fun occasionally but i dont need to be the fastest guy out there. So heres the proof that you can make good power while spooling quickly!
This is what everyone says to me at car meets and on the forum, but oh wait, it does work! I went from a turbonetics 78mm "hurricane" to a Precision 76mm GTS.
(NEW DYNO NUMBERS This is on a load bearing "dyno dynamics" dyno)
(OLD DYNO NUMBERS! non-load bearing dyno)
You might have seen my sticky on https://ls1tech.com/forums/forced-in...ifold-kit.html and in there I explained how i built this car to be A STREET CAR. not built for 1/4 mile times or to compete with, but to be a quick spooling street machine! I am sooooooo happy with how it turned out! On the same dyno it was previosly making 580ish rwhp and 650ish rwtq on about 13psi and now its set between 14-15psi, spools much quicker, pulls much harder, and is wayy more fun to drive!
yes an 88mm would pull better up top, but would also spool a lot slower and would be less fun for me on the street. ill prob take this to the track for fun occasionally but i dont need to be the fastest guy out there. So heres the proof that you can make good power while spooling quickly!
Last edited by KILLER-LS1; 12-27-2010 at 12:04 PM.
12-26-2010, 08:19 PM
#3
Congrats on the numbers, the people who said it wouldn't work just really don't know what they are talking about. However 14-15 psi on 91 oct doesn't exactly qualify for "super safe" status regardless of how little timing you have in it since pump gas is garbage and can fluctuate from pump to pump. You say it's a load bearing dyno, why is it taking so long to spool that 76 with that many cubes? My 347ci on a 76gts spooled at that same RPM area on a non-loaded dynojet.
I know this post is just sounding like I am ragging on you but I don't want it to come across that way.
I know this post is just sounding like I am ragging on you but I don't want it to come across that way.
12-26-2010, 08:46 PM
#4
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[QUOTE=KILLER-LS1;14282023]
yes an 88mm would pull better up top, but would also spool a lot slower and would be less fun for me on the street. ill prob take this to the track for fun occasionally but i dont need to be the fastest guy out there. So heres the proof that you can make good power while spooling quickly
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[QUOTE=nghisus;14282344]
yes an 88mm would pull better up top, but would also spool a lot slower and would be less fun for me on the street. ill prob take this to the track for fun occasionally but i dont need to be the fastest guy out there. So heres the proof that you can make good power while spooling quickly![/QUOTE
More area under the curve is definitely better than peak numbers. I think people over simplify the debate over the wheel sizes of the turbo. There's guys making good power on 76's, 80's, 88's and just as many who can't get them to perform well. That's why real world knowledge and advice can't be under estimated. Thanks for posting because it's real world information, how about some details on your set up and turbo so that when someone does a search in the future they have some detail.
yes an 88mm would pull better up top, but would also spool a lot slower and would be less fun for me on the street. ill prob take this to the track for fun occasionally but i dont need to be the fastest guy out there. So heres the proof that you can make good power while spooling quickly!
[/QUOTEMore area under the curve is definitely better than peak numbers.
12-26-2010, 09:19 PM
#6
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[QUOTE=mike13;14282407]
I think people over simplify the debate over the wheel sizes of the turbo. There's guys making good power on 76's, 80's, 88's and just as many who can't get them to perform well. That's why real world knowledge and advice can't be under estimated. Thanks for posting because it's real world information, how about some details on your set up and turbo so that when someone does a search in the future they have some detail. It was just my personal opinion for his particular use. I do agree taken directly it is a bit over generalized. With tuning and all the other variables you could probably get an endless amount of output or the same with different brands and sizes of turbos. He has the turbo setup on his build thread, unless you meant more specifically for this turbo in particular.
I think people over simplify the debate over the wheel sizes of the turbo. There's guys making good power on 76's, 80's, 88's and just as many who can't get them to perform well. That's why real world knowledge and advice can't be under estimated. Thanks for posting because it's real world information, how about some details on your set up and turbo so that when someone does a search in the future they have some detail.
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12-27-2010, 03:40 AM
#8
Congrats on the numbers, the people who said it wouldn't work just really don't know what they are talking about. However 14-15 psi on 91 oct doesn't exactly qualify for "super safe" status regardless of how little timing you have in it since pump gas is garbage and can fluctuate from pump to pump. You say it's a load bearing dyno, why is it taking so long to spool that 76 with that many cubes? My 347ci on a 76gts spooled at that same RPM area on a non-loaded dynojet.
I know this post is just sounding like I am ragging on you but I don't want it to come across that way.
I know this post is just sounding like I am ragging on you but I don't want it to come across that way.
12-27-2010, 10:54 AM
#11
12-27-2010, 11:51 AM
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Youre only spinning to 6k, of course the smaller turbo will be better for you. Im curious what the dyno looks like for the 78, it probably doesnt drop 170hp from 5-6k.
Not being negative, you are happy with the results and all that matters.
Not being negative, you are happy with the results and all that matters.
