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Im going to go out on a limb and guess his motor was stock? Because to get the turbo to work at its max potential the LT1 has to be built. The misconception at the time of the sts back then was it was advertised as a bolt on kit and several people ( more so the twin turbo'ed vetts) were sadly disappointed at the performance on bone stock engines. Although, i had to get my old 95Firehawks motor built to break 500+ in Vegas in a 100deg garage at 10lbs where my friends SS'camaro only needed a cam with the same turbo specs. At sea level and 18lbs it was pushing about 580rw... oh those were the days
t67 /.81
Aside from his being an LS1 car you are exactly right. Engine itself was completely stock. He may have had some longtube headers but again it just didnt really pickup until the upper rpm range.
Originally Posted by stingr
I think the sts system has to small of a turbine and it chokes out a v8 engine. I find sizing the turbine the same and managing heat works well. I lose maybe 500rpm of spool. Big deal. It's not what I would call laggy. Could likely improve spool response with ball bearing. I like the robustness of journal bearing for a street car. This gt45 i have works well.
You are probably right. I do remember the turbo being on the smaller side.
Aside from his being an LS1 car you are exactly right. Engine itself was completely stock. He may have had some longtube headers but again it just didnt really pickup until the upper rpm range.
.
My friends LS/ss'camaro with the same t67/.81 innercooled sts made 530rw with a custom cut cam. On race fuel and forged internals Leading Edge Performance who built our cars maxed his out at about 680rw.. its definitely a capable setup but the motors got to be built for it. Guess all thats in the past now 😞
Aside from his being an LS1 car you are exactly right. Engine itself was completely stock. He may have had some longtube headers but again it just didnt really pickup until the upper rpm range.
You are probably right. I do remember the turbo being on the smaller side.
longitudes slow the ramp in big time. I have hooker shorties and the only reason I have those is to change the plugs easier. Stock manifolds make that job terrible. i just sheilded and wrapped the cats and y pipe which I'd previously left bare because I ran out of wrap. Just by finishing the wrap all the way back this turbo now really starts spooling up well by 2800rpm. Wouldn't have thought it would have made that big of a difference. The next thing I'm going to do is a water methanol system I'm peicing together. Buying the kits are crazy now and they are easy to make for way less.
Because water meth systems have become so expensive i decided to make my own sourcing parts. This is a fraction of the cost of a new kit and has the important parts where it matters most. Will turn on at about 5psi boost.
sick setup, nice to see people still coming up with stuff on the cheap!
That's the idea behind hot rodding. It kinda sucks seeing nothing but big money being thrown at cars. I like seeing threads with people coming up with different ideas or building on existing ideas.
Impressive for the turbo used. That’s the old gt45 clone. They are dinosaurs in terms of “spool” and power production. I’m no knocking it as I know they are super cheap. But you could prob knock 500rpm+ off your “Spool times” and make another 5% power per pound with a decent S366 style clone from VS racing. Still relatively cheap and light years ahead in power per pound and lag. Even a 70/65 or similar would be a massive upgrade.
Also with such low boost you could likely remove that IC. Can’t be very efficient for the size and it has poor airflow. The long charge pipe acts similar to an IC. Worth a try anyway def won’t hurt anything. May knock off a little weight and spool time and actually gain performance. Then just spray the water/meth pre turbo to make best use of it.
Impressive for the turbo used. That’s the old gt45 clone. They are dinosaurs in terms of “spool” and power production. I’m no knocking it as I know they are super cheap. But you could prob knock 500rpm+ off your “Spool times” and make another 5% power per pound with a decent S366 style clone from VS racing. Still relatively cheap and light years ahead in power per pound and lag. Even a 70/65 or similar would be a massive upgrade.
Also with such low boost you could likely remove that IC. Can’t be very efficient for the size and it has poor airflow. The long charge pipe acts similar to an IC. Worth a try anyway def won’t hurt anything. May knock off a little weight and spool time and actually gain performance. Then just spray the water/meth pre turbo to make best use of it.
Either way… good luck. Let us know how it goes.
I agree I could likely get more power out of a different turbo but this works pretty good. I'd like to eventually use aluminum pipe on the cold side rather than steel to reduce weight. I don't think spraying pre turbo on a rear mount would work very well. To long of a run for the meth to loose suspension in the air. I've heard spraying preturbo is also hard on compressor blades. I'm pretty happy with this. It's a decent quick street car at 8psi of boost out of this turbo.
Super common myth. Spraying pre turbo is the best place hands down. It’s the only method that ups the efficiency of the turbo as its compressing. Been doing it over 20 years now on dozens of turbos and I’ve never had any sort of issue with blade damage. Those old images of blade damage are diesel applications where guys are piping large volumes of un-atomized water straight into the blades of tiny turbos spinning at 120k plus over long periods of time.
As far as loss of suspension, that all depends on the air temps. Generally non-intercooled setups charge temps will be over 150*. So the meth flashes into a gas very quickly in the turbo itself. It won’t fall out of suspension unless the charge temps drop below that on the way to the TB. The only real danger is if you spray enough meth to get a flammable AFR in the charge pipe. Then have a backfire through the intake… it could get ugly. But as far as a little water/meth condensation on your charge piping I wouldn’t sweat it. I’ve done it with remote setups. Works great.
Super common myth. Spraying pre turbo is the best place hands down. It’s the only method that ups the efficiency of the turbo as its compressing. Been doing it over 20 years now on dozens of turbos and I’ve never had any sort of issue with blade damage. Those old images of blade damage are diesel applications where guys are piping large volumes of un-atomized water straight into the blades of tiny turbos spinning at 120k plus over long periods of time.
As far as loss of suspension, that all depends on the air temps. Generally non-intercooled setups charge temps will be over 150*. So the meth flashes into a gas very quickly in the turbo itself. It won’t fall out of suspension unless the charge temps drop below that on the way to the TB. The only real danger is if you spray enough meth to get a flammable AFR in the charge pipe. Then have a backfire through the intake… it could get ugly. But as far as a little water/meth condensation on your charge piping I wouldn’t sweat it. I’ve done it with remote setups. Works great.
I did notice that once I funneled the air to that intercooler my intake pipe to the manifold was really cold after driving as opposed to how warm it was getting before. I think I'm going to keep the intercooler because my methanol tank is only about 2 liters and I don't want to run out and have no cooling at all. The water meth injection I'm using it more as a cheap octane booster being the lt1 compression is a bit high for straight pump gas. I'm not trying to break records with this setup just have a fun reasonable reliable street car built at not a crazy price. If I was going to go for it. Lq4 with forged pistons and about 18psi boost. That would be a very quick car.
Impressive for the turbo used. That’s the old gt45 clone. They are dinosaurs in terms of “spool” and power production. I’m no knocking it as I know they are super cheap. But you could prob knock 500rpm+ off your “Spool times” and make another 5% power per pound with a decent S366 style clone from VS racing. Still relatively cheap and light years ahead in power per pound and lag. Even a 70/65 or similar would be a massive upgrade.
Also with such low boost you could likely remove that IC. Can’t be very efficient for the size and it has poor airflow. The long charge pipe acts similar to an IC. Worth a try anyway def won’t hurt anything. May knock off a little weight and spool time and actually gain performance. Then just spray the water/meth pre turbo to make best use of it.
Either way… good luck. Let us know how it goes.
what are your thoughts on the vsracing 75/78 turbo? I'm considering maybe at some oint switching to this one with the .96ar turbine. Mine has a 1.05 ar i think the .96 would help with spool. Maybe spool up by 3000rpm or maybe thats not realistic.
The way they measure the scroll volute differs brand to brand. The "1.05" and ".96" are pretty much the same thing. Not worthwhile to swap between the two on the same turbo.
However, the 78/75 is a MUCH newer unit that will spool quicker hands down. That being said, any turbo with an under driven compressor isn't ideal. Ideally you want the exh wheel larger than the compressor wheel. It also depends how much boost you want to run (or really how much airflow you need). And what your budget is.
You can get a billet 78/75 on ebay for like $250. (cheaper than vs racing). We just installed one on a buddys 5.3 ls daily and went with the even smaller .81 T4. It spools very quickly (mounted up front on factory manifold) and he had a super mild goal of 10lbs. Something like that would work really well on a remote setup with limited boost goals. Would be night/day vs what you have now.
If moneys not a concern, I’d look at smaller compressors with your setup. Something like an S366 is a light switch on a small block and will make 550whp. The VSR copies of these are ok. But a Borg Cast S366 is better.
Just depends on your budget. 78/75 is likely the cheapest option that will work well. (the sellers take less if you make a lower offer)
The way they measure the scroll volute differs brand to brand. The "1.05" and ".96" are pretty much the same thing. Not worthwhile to swap between the two on the same turbo.
However, the 78/75 is a MUCH newer unit that will spool quicker hands down. That being said, any turbo with an under driven compressor isn't ideal. Ideally you want the exh wheel larger than the compressor wheel. It also depends how much boost you want to run (or really how much airflow you need). And what your budget is.
You can get a billet 78/75 on ebay for like $250. (cheaper than vs racing). We just installed one on a buddys 5.3 ls daily and went with the even smaller .81 T4. It spools very quickly (mounted up front on factory manifold) and he had a super mild goal of 10lbs. Something like that would work really well on a remote setup with limited boost goals. Would be night/day vs what you have now.
If moneys not a concern, I’d look at smaller compressors with your setup. Something like an S366 is a light switch on a small block and will make 550whp. The VSR copies of these are ok. But a Borg Cast S366 is better.
Just depends on your budget. 78/75 is likely the cheapest option that will work well. (the sellers take less if you make a lower offer)
right now I'm keeping the boost pretty low. Like 8 to 9 psi due to the fmu ratio making fuel pressure so high it would likely stick the injectors at higher boost levels. Also I'm running high compression on this engine for boost. Faster spool at would be great keeping the same boost level though. Thanks for the opinion and help. It might be something I look at more seriously in the future.
The intercooler closed in the plastic plate i made. A few holes drilled in the splash gaurd with mesh epoxied in to keep rocks and debris out. This works very good at cooling the intake charge
The way they measure the scroll volute differs brand to brand. The "1.05" and ".96" are pretty much the same thing. Not worthwhile to swap between the two on the same turbo.
However, the 78/75 is a MUCH newer unit that will spool quicker hands down. That being said, any turbo with an under driven compressor isn't ideal. Ideally you want the exh wheel larger than the compressor wheel. It also depends how much boost you want to run (or really how much airflow you need). And what your budget is.
You can get a billet 78/75 on ebay for like $250. (cheaper than vs racing). We just installed one on a buddys 5.3 ls daily and went with the even smaller .81 T4. It spools very quickly (mounted up front on factory manifold) and he had a super mild goal of 10lbs. Something like that would work really well on a remote setup with limited boost goals. Would be night/day vs what you have now.
If moneys not a concern, I’d look at smaller compressors with your setup. Something like an S366 is a light switch on a small block and will make 550whp. The VSR copies of these are ok. But a Borg Cast S366 is better.
Just depends on your budget. 78/75 is likely the cheapest option that will work well. (the sellers take less if you make a lower offer)
id wonder if an .81 ar would create to much backpressure which rear mounts are already quite bad for. Would spool quickly i bet. I ran twin 57trim to4e on a challenger a few years back just off the manifols in a midmount deal. Those had a 63 ar and spooled lighting quick.
I can say on a 5.3 LS with at 8-10lbs the .81 T4 is fine. Little less than 2:1 backpressure. I believe the newer 5.3’s made more power than the older LT1. So you should be fine. He had a small cam as well. I ran .63 t3 twins on a 5.3 as well. I still had 1:1 back pressure at 19lbs on that setup.
You can get the fully adjustable rising rate FMU’s now pretty cheap. ($50). Set whatever rising rate ratio you want to dial in the AFR decently. I use one on my supercharged wave runner, works great. Spraying 100% meth injection in it as well for even more fuel.
Can run up to 100psi or so before you start to run into injector issues with pressure. Depends on the injectors too. The guys running 225 dekas routinely run up to 140psi w mechanical pumps on alky.
I can say on a 5.3 LS with at 8-10lbs the .81 T4 is fine. Little less than 2:1 backpressure. I believe the newer 5.3’s made more power than the older LT1. So you should be fine. He had a small cam as well. I ran .63 t3 twins on a 5.3 as well. I still had 1:1 back pressure at 19lbs on that setup.
You can get the fully adjustable rising rate FMU’s now pretty cheap. ($50). Set whatever rising rate ratio you want to dial in the AFR decently. I use one on my supercharged wave runner, works great. Spraying 100% meth injection in it as well for even more fuel.
Can run up to 100psi or so before you start to run into injector issues with pressure. Depends on the injectors too. The guys running 225 dekas routinely run up to 140psi w mechanical pumps on alky.
Good luck.
I'm running the oem lt1 injectors so im keeping the overall fuel pressure around 91psi. Ive heard they lock up at around 95 psi or so. Theories say that with this fuel pressure on these injectors it's good for a bit over 500hp. Sure feels like that and then some. Lol. That's the reason I'm keeping the boost limited right now. That and oem bottom end that has had minor work done on it. Reading the plugs and afrs I'm pretty good at around that 8 to 8.5 psi range right now. I have to keep it somewhat reliable. Broken down is no fun and I'm not racing this thing so it's just a fun street car that kinda reminds me of what I wanted back in high school.
I roasted the oem pump so I just added a 255lph pump and hotwire kit. I did the trap door thing. Dropping the rear on this seemed crazy waste of time. I've noticed that the pump seems to cut out for a second if it goes to 90psi. I think there is a prv in that pump. I'm going to up the injectors to 36 or 42 lbs and lower the fmu pressure. I think this will fix that problem. I sure like not hearing an external pump. I also added a guauge to watch pressure
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