My observations and opinions of current street/strip turbo LS trends.
08-11-2012, 05:09 PM
#21
OP cant agree more. I have had my experience with all three
I started out my turbo build 6 years ago with a STS kit sporting the garrett GT76, 67mm turbine I thought it was good for what it was 500+RWHP and a lot of fun, Later hurt the motor then decided to do a front mount setup. Used the same turbo up front because I already had it and the car definitely was hitting a wall in the upper 5K range you could feel it die off before it reached 6K at one point in time while tuning I held it to the floor board in second while the car was a T56 and it wouldn't turn past 6300 according to the logs . So I posted up what people thought about turbine sizing and I yanked the baby turbo. Let a few guys with larger turbines talk me into using one and refabbed the kit to accept a S480 T6 1.32 A/R divided and what a world of difference car pulls hard all the way to 7K now. Adding some meth and getting ready to turn it up some more and add some timing cant wait to see what its capable of. I was worried about the car spooling the turbo but it seems to have no problem.
Like stated above, timing, A/F ratio has alot to do with it. Also if your running an auto the converter plays a huge roll in loading to build boost a lot of aspects to look at. But people shouldn't be scared of the larger turbine wheels because of fear of spool. LS motors love to breath.
I started out my turbo build 6 years ago with a STS kit sporting the garrett GT76, 67mm turbine I thought it was good for what it was 500+RWHP and a lot of fun, Later hurt the motor then decided to do a front mount setup. Used the same turbo up front because I already had it and the car definitely was hitting a wall in the upper 5K range you could feel it die off before it reached 6K at one point in time while tuning I held it to the floor board in second while the car was a T56 and it wouldn't turn past 6300 according to the logs . So I posted up what people thought about turbine sizing and I yanked the baby turbo. Let a few guys with larger turbines talk me into using one and refabbed the kit to accept a S480 T6 1.32 A/R divided and what a world of difference car pulls hard all the way to 7K now. Adding some meth and getting ready to turn it up some more and add some timing cant wait to see what its capable of. I was worried about the car spooling the turbo but it seems to have no problem.
Like stated above, timing, A/F ratio has alot to do with it. Also if your running an auto the converter plays a huge roll in loading to build boost a lot of aspects to look at. But people shouldn't be scared of the larger turbine wheels because of fear of spool. LS motors love to breath.
08-11-2012, 06:33 PM
#22
Launching!
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ok i gotta chime in on this one lol everything you said is great but i know for guys like me who are relatively new to wrenching..... its crazy hard to find all the MATCHING components for a set up. from turbo size, to cam, to torque converter etc.
i read everything i could on turbos and posted threads with all my plans and the threads just turned into a debate between gurus. at the end of the day i still couldn't understand what all they were saying and i just shot from the hip and ended up with my best guest.
it would be great to have a guide that helps you MATCH up components for the goals your trying to get. i read and read and guys some of us just don't have that mechanical know how even if we read it to understand it all. i ended up with twin 58mm 84a/r t3 turbos for my 5.3 build from all info given on my threads and now i think i went to small anyway good post just food for thought .. you gurus ... keep sharing your knowledge cuz it is needed and appreciated
i read everything i could on turbos and posted threads with all my plans and the threads just turned into a debate between gurus. at the end of the day i still couldn't understand what all they were saying and i just shot from the hip and ended up with my best guest.
it would be great to have a guide that helps you MATCH up components for the goals your trying to get. i read and read and guys some of us just don't have that mechanical know how even if we read it to understand it all. i ended up with twin 58mm 84a/r t3 turbos for my 5.3 build from all info given on my threads and now i think i went to small anyway good post just food for thought .. you gurus ... keep sharing your knowledge cuz it is needed and appreciated
08-11-2012, 06:44 PM
#23
I think the most important thing is learning to tune yourself. No one will put the time into getting your car perfect that you would.
That being said, my next project will be a stock motor with good gaskets and hardware and valvesprings and a huge turbo
That being said, my next project will be a stock motor with good gaskets and hardware and valvesprings and a huge turbo
08-11-2012, 08:25 PM
#25
On The Tree
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thanks for this topic and more discussion is welcomed !!!!one thing i,m finding is the qouted hp figures for compressor wheels obviously dont match what is capable on these bigger ls motors due to the turbine factor !!!! i think people see a certain say 1000 hp turbo make 800 rwhp on a 3litre rb motor or toyota 2jz motor then think fark my 5.7 or 6.0l should kill those!!!! not the case the turbine wheel that the smaller motor uses its full potential is killed by the bigger motor resulting in less power etc !!!! this is making me think with my setup its a lq9 408ci stroker ran an s475 with t6 1.32ar 96mm turbine with good results 796rwhp on c16 and 20psi on stock 241s intake etc custom turbo cam dont know specs !!!! its currently at shop getting a s400 hp-88 mm turbo same t6 1.32ar 96 a set of ls7 style aussie made 6 bolt heads ported for turbo setup!!! custom sheet metal intake t/b etc and tuned on e85 !!!! will be interesting with the better flowing heads intake etc and just the bigger 88mm compessor wheel same turbine setup will do!!!! i am seeing now that the 88mm s500 with its 111mm turbine would have been a better option but it,s too large to fit !!!! this is the thing my s488 and the s500- 88 are both rated at 1500hp but the s500 with it,s bigger turbine would be much better with 400+ ci !!!! any thoughts and sorry for raving on but more info and discusion only helps people like me and others understand whats best!!!!cheers
08-11-2012, 08:56 PM
#27
thanks for this topic and more discussion is welcomed !!!!one thing i,m finding is the qouted hp figures for compressor wheels obviously dont match what is capable on these bigger ls motors due to the turbine factor !!!! i think people see a certain say 1000 hp turbo make 800 rwhp on a 3litre rb motor or toyota 2jz motor then think fark my 5.7 or 6.0l should kill those!!!! not the case the turbine wheel that the smaller motor uses its full potential is killed by the bigger motor resulting in less power etc !!!! this is making me think with my setup its a lq9 408ci stroker ran an s475 with t6 1.32ar 96mm turbine with good results 796rwhp on c16 and 20psi on stock 241s intake etc custom turbo cam dont know specs !!!! its currently at shop getting a s400 hp-88 mm turbo same t6 1.32ar 96 a set of ls7 style aussie made 6 bolt heads ported for turbo setup!!! custom sheet metal intake t/b etc and tuned on e85 !!!! will be interesting with the better flowing heads intake etc and just the bigger 88mm compessor wheel same turbine setup will do!!!! i am seeing now that the 88mm s500 with its 111mm turbine would have been a better option but it,s too large to fit !!!! this is the thing my s488 and the s500- 88 are both rated at 1500hp but the s500 with it,s bigger turbine would be much better with 400+ ci !!!! any thoughts and sorry for raving on but more info and discusion only helps people like me and others understand whats best!!!!cheers
08-11-2012, 10:57 PM
#30
I don't know if he was joking or not, but I don't see how you could make 950rwhp with a PT7675 even through a 6 speed on a 5.7 LS1.
875rwhp-900rwhp would be possible with a good set of heads and intake, but an unlocked auto is going to be around 775-800rwhp maybe 850rwhp. This is on a generous dyno.
875rwhp-900rwhp would be possible with a good set of heads and intake, but an unlocked auto is going to be around 775-800rwhp maybe 850rwhp. This is on a generous dyno.
08-12-2012, 12:08 PM
#34
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The following thoughts and rambling is directed towards what I see as the majority of the street/strip turbo LS crowd. As a disclaimer, the following is my -opinion- but it is backed by experience. Oh yeah, and I don't sugar coat things.
First off, the same with anything, a turbo LS needs to be looked at as an entire, matched combination. Set your goals first and then decide on components that will allow you to reach those goals.
That being said, big compressor wheels and tiny turbines seem to be all the rage these days. Guess it makes for an affordable turbo. It also makes for sub-par performance.
If you've decided that you absolutely must use a 76mm compressor and a 12mm turbine , really don't even bother with a "what cam should I use" thread because if you have money for a cam that will do absolutely nothing for you, it should be spent towards a turbo that is actually capable of efficiently making power.
Why does your car nose over at 5k? Chances are your turbo belongs in the dumpster or you have way too big of an engine for your current turbo. Want to make 950rwhp and 7000rpm with a PT7675? Run a 5.3. Want to spend more money on a 408 and max out the same turbo at 775rwhp and 5200rpm? Probably not, but people do it.
Not sure why but it seems many people shy away from twin setups. Twins absolutely cannot be beat in terms of a fun street car. Even an undersized pair of twins that make nearly instant boost will still outshine most similarly capable singles up top. I don't like lag so I always run twins. And I'm not talking logged boost VS wot, I'm talking about having driven countless amount of turbo cars and knowing the difference in feel when you roll on the gas of a single or a small set of similarly capable twins. Transient response is what you feel in normal every day driving and you get it in spades with a good twin setup.
Rear mount? Sure they can be fast at the strip as you have time to get the things online while you're bumping it in. As for a fun driving combination on the street? None that I've driven accomplish that. Wouldn't use it if it was given to me. (refer to, I don't like lag so I run twins/etc/etc)
Back to the cam thing. I'll use the cams we have available as examples because well, why not. I designed them and tuned them over the years so at least I can speak about them with experience.
TUO-216/216 114lsa. I would plan on bigger if I planned on over 700rwhp.
TU1-225/225 113lsa. I may consider a bigger cam if 950rwhp wasn't enough.
TU2-236/236 112.5lsa. If you have a combo capable of 1200rwhp and 7800rpm than this cam will work great.
Guess the point I'm trying to make on cams is that I think 90% of people cheap out on their turbo then over-cam the hell out of it thinking it will somehow compensate when in reality all you did was soften up the bottom end and midrange for no gains up top.
So, in closing, if you're building or planning a build on a turbo LS and your goal is to not be disappointed, THE most important thing to buy is a good turbocharger or turbochargers. Second is valvesprings. If you cheaped out on the turbo so you could buy more cubes, a different intake manifold, a different cam, a set of heads, a throttle body, an electric water pump, or even a torque converter, you've made a poor decision.
Rant over, let the flames begin
First off, the same with anything, a turbo LS needs to be looked at as an entire, matched combination. Set your goals first and then decide on components that will allow you to reach those goals.
That being said, big compressor wheels and tiny turbines seem to be all the rage these days. Guess it makes for an affordable turbo. It also makes for sub-par performance.
If you've decided that you absolutely must use a 76mm compressor and a 12mm turbine
, really don't even bother with a "what cam should I use" thread because if you have money for a cam that will do absolutely nothing for you, it should be spent towards a turbo that is actually capable of efficiently making power. Why does your car nose over at 5k? Chances are your turbo belongs in the dumpster or you have way too big of an engine for your current turbo. Want to make 950rwhp and 7000rpm with a PT7675? Run a 5.3. Want to spend more money on a 408 and max out the same turbo at 775rwhp and 5200rpm? Probably not, but people do it.
Not sure why but it seems many people shy away from twin setups. Twins absolutely cannot be beat in terms of a fun street car. Even an undersized pair of twins that make nearly instant boost will still outshine most similarly capable singles up top. I don't like lag so I always run twins. And I'm not talking logged boost VS wot, I'm talking about having driven countless amount of turbo cars and knowing the difference in feel when you roll on the gas of a single or a small set of similarly capable twins. Transient response is what you feel in normal every day driving and you get it in spades with a good twin setup.
Rear mount? Sure they can be fast at the strip as you have time to get the things online while you're bumping it in. As for a fun driving combination on the street? None that I've driven accomplish that. Wouldn't use it if it was given to me. (refer to, I don't like lag so I run twins/etc/etc)
Back to the cam thing. I'll use the cams we have available as examples because well, why not. I designed them and tuned them over the years so at least I can speak about them with experience.
TUO-216/216 114lsa. I would plan on bigger if I planned on over 700rwhp.
TU1-225/225 113lsa. I may consider a bigger cam if 950rwhp wasn't enough.
TU2-236/236 112.5lsa. If you have a combo capable of 1200rwhp and 7800rpm than this cam will work great.
Guess the point I'm trying to make on cams is that I think 90% of people cheap out on their turbo then over-cam the hell out of it thinking it will somehow compensate when in reality all you did was soften up the bottom end and midrange for no gains up top.
So, in closing, if you're building or planning a build on a turbo LS and your goal is to not be disappointed, THE most important thing to buy is a good turbocharger or turbochargers. Second is valvesprings. If you cheaped out on the turbo so you could buy more cubes, a different intake manifold, a different cam, a set of heads, a throttle body, an electric water pump, or even a torque converter, you've made a poor decision.
Rant over, let the flames begin
Thank you!!!!! Exactly why I went twins!! I want street car and drive the car!! Not just a drag car or Dyno queen!!!
08-12-2012, 12:18 PM
#35
This thread is good and all and I agree 100% BUT the only issue I have with it is people still are not giving out proven combos that work. Speed Inc has and tuned some of the baddest turbo lsx cars around so they know a thing or 10 but why don't you give some of us some combos? Everyone seems to be doing stock bottom end 5.3 and 6.0 build so what cam/intake/turbo would you use and why? Then a classic 370 build with a Vic jr intake? You did elaborate some but for the budget guys what would you do?
08-12-2012, 12:55 PM
#37
A business would be stupid to give out free budget info. They aren't getting any business from a budget guy. They pay $$$ per month just to advertise. And the sad thing is there are alot of empty wallet budget guys here. It would be tough to sponsor this board.
08-12-2012, 01:14 PM
#38
I'm not asking for specifics, but more of a general rule of thumb. Like a NA guy uses steep gears and big stalls, ok well turbo cars will use...? I know what you guys are saying and I agree but a sponsor on here should also be helpfull and give budget guys some insite on what to buy or a round-about what to look for/buy.
08-12-2012, 02:22 PM
#40
I'm not asking for specifics, but more of a general rule of thumb. Like a NA guy uses steep gears and big stalls, ok well turbo cars will use...? I know what you guys are saying and I agree but a sponsor on here should also be helpfull and give budget guys some insite on what to buy or a round-about what to look for/buy.