My somewhat coherent thread on the topic of street/strip turbo LS combinations.
08-18-2012, 04:47 PM
#1
FormerVendor
Thread Starter
My somewhat coherent thread on the topic of street/strip turbo LS combinations. This is a bit hard to do as their are really a limitless amount of combinations you can put together. This is all mostly generalizations, not an exact parts list. Just thought it may be of some help to people as I've driven and tuned a ton of turbo cars so here I can share some insight as to what some of them are like.
Let me start by going back to what I touched on in my other thread. The first and most important decision to make after deciding on a power goal is what turbocharger or turbochargers to buy.
My absolute favorite is the Garrett GT stuff. Yes all other turbos can make similar power but I've yet to experience any faster response then a set of twin Garrett's. I don't build turbos so I don't know of the exact internal differences but I would guess it just comes down to shaft/wheel weight and maybe the bearings.
Precision is also really nice and have been very reliable. We mostly use 7675's and smaller from them. Having driven several small twin setups with both Garrett and Precision turbos I would say the only downside to the precisions is they do not have the insanely quick transient response as the Garretts.
Turbonetics have been reliable but you need to run something that has a fairly well matched compressor to turbine. The TC series 76 and 78 does not fall into that category, IMO. Even in a twin configuration the turbine is just too damn small to efficiently drive the compressor. I would run twin TC67's over twin TC76's or 78's any day. (all with F-trim turbine). As for a single TC, I know people do it but I would not. Why? Because I've driven cars with a single TC76 and I've driven cars with a single 7675. 7675 spools faster and can make a couple hundred more horsepower. More expensive yes but well worth it.
Comp seems to make a quality well built product but from what I've seen needs to build them with a turbine that's a better match for the compressor. I'm sure they can build some awesome stuff but so far they seem to be generating some fairly high backpressure numbers.
Borg warner is in the category of, looks like the most bad-*** turbos I've never used. Would like to try some of their stuff but I can't speak to them with any experience. The EFR series looks awesome- http://www.turbodriven.com/en/perfor...urbos/efr.aspx
Ok, so a few combos. This is going to be pretty basic, not an entire exacting list of what you should buy but more of a general guideline of combos I've experienced and liked.
First on the list is going to be what I think is the ultimate street/strip setup. The almighty Garrett/Tial GT35R in twin configuration. These things have amazing response. Even on a 346 and a manual trans you can practically be into boost before the clutch is fully engaged while pulling away from a stop light at 1/3 throttle. Cruising along in 2nd or 3rd and roll onto the gas as you watch 2 black tracks in your rear view. Along with all of this transient response awesomeness they are still capable of 1000 at the tires. I recommend using the Tial stainless v-band housing. Say, .63 a/r for 346ci and .82 for 400ci, 1.06 for 427. Not cheap but usually parts that are ******* awesome don't fall under the ultra-budget category.
On more of a budget but still want twins capable of nearly the same power? Precision has in their entry level line a 6076E. Rated at 610hp each with a 59mm compressor wheel and p-trim exhaust wheel these aren't exactly new technology but would still make a kick *** twin setup and are only $599 each. I've used some similar turbos from them with a 54mm/Ptrim combo on their V-band exhaust housing and they were excellent with very small packaging.
More budget? I mentioned it in the other thread but an LQ9 with twin stock GN turbos is a blast. 600rwhp and practically instant boost. A few reasons I can't recommend it is the buick turbos are a bit strange and the internal gates won't regulate boost down to a low enough level if you want to upgrade them down the road. If you're putting a swap car together and want a fun inexpensive setup than I highly recommend it.
Not enough power? Ok, another great streetable combo that we've built many of is simply a 408 with twin 6766's, TU2 cam, any decent aftermarket head really, LS6 or LS2 intake manifold, will do 1,150+rwhp and turn to 7700+rpm. LS9 gaskets and studs will live at this level if you're tune is spot on (and you are one of few that actually run the proper octane fuel) but for more reliability I think going to an aftermarket block such as LSX, RHS or ERL with 6-bolts/cyl over 1100rwhp is a very good idea.
You have some strange aversion towards twin turbos? Ok, as much as I really don't like single setups I must admit that something like a 346 and a PT7675 is pretty bad ***. Pair it up with a TU1 cam and it will do a bit over 900rwhp with an M6. Fun combination. Do not try to run 400+ cubes with this turbo unless you want to make about 150 less rwhp and shift it at 5k rpm. This is why it's important to put together a matched combo. Too many cubes on a smaller single like this will turn a potentially great combo into a tractor.
Bigger singles than the 7675? I've driven quite a few of them and none of them are as responsive as I would like on the street, especially with a manual trans. Rolling onto the gas with moderate input kind of leaves you waiting a bit and then a hard midrange hit. Yes they can make a lot of power but I wouldn't personally build one knowing I can put a twin setup together for the same money, same horsepower but faster response. Also, I find it easier to package 2 small twins and their respective parts than a giant single with a monster downpipe.
Journal vs ball bearing. On the same turbo going from journal to BB will not make much difference in logged boost vs WOT. It will still hit peak boost at almost the same rpm. Difference is in transients. Pull away from a stop and roll on the gas, BB units feel more responsive, more of a liquid transition into boost.
Almost forgot about APS! I know many have had reliability issues with the turbos supplied with the system but otherwise I think these are bad-*** systems for a street car. Very capable hp wise and very little lag. If I was going to build a car that an APS system was available for I would strongly consider using it. Not sure what's still out there and available still as far as new systems, to get one you'll probably have to scrounge the classifieds.
Keep in mind that running a very small pair of twins, even something that could hit peak boost by 3k rpm will not choke the rpm range hard like an undersized single.
Rear mount. Yes they can be fast with a stalled auto but again, I would never do it. Seems like nearly as much work and cost as building a traditional turbo setup. I've never driven one that had any good part throttle response and many I've driven just start to come online at the top of each gear (manual trans).
Compression ratios. Generally. I prefer something close to 10.0-1 More for all out race cars and less if you want a bit more room for error before breaking something. Definitely do not recommend anything lower than 9.0-1, starts to feel a bit soggy when not in boost.
Fuel. I like to tune to a reasonable boost/power level on pump fuel (lets say conservatively 10-12psi for most setups) and add or run race fuel above that. I don't trust meth systems enough to rely on them for octane or fueling. If you want to conveniently run 1000+rwhp on the street then dual fuel systems and staged injection works nicely though I don't find it much of an inconvenience to use race fuel when it's needed.
Heads- Like most other aspects of a turbo engine, build it to make power naturally aspirated and it will be that much more efficient on boost. Stock heads can still support a ton of power. Anything aftermarket is going to have a thicker deck surface which will help with head gasket sealing.
Intakes- Not a fan of single planes and the low profile 'Tron' elbows. Would much rather use an LS6/LS7/LS2 intake up to around 1200rwhp or so. The edelbrock pro-flo efi and similar work great but it's really hard to beat a factory composite intake in terms of power potential and overall driveability. Something like a big sheetmetal intake that would kill low end response on a naturally aspirated car will to some point do the same on a turbo engine by contributing to the feeling of lag.
Intercooling. The bigger ebay units are OK. Certainly a deal for the price. For a bit more money you can run a Precision, Bell, or Griffin and they are much more efficient. Precisions "825hp" air to air unit actually supports closer to 1000 and fits perfectly in the nose of a 4th gen while keeping all of the radiator shrouds in tact. (must remove bumper support). For the dragstrip an air to water with ice is unbeatable. Works nice on the street as well but would probably not use it on a car that's a roll racer or sees extended time at WOT. Be careful on going to small with an air to air. A 10psi drop across the core means 10psi more turbine drive pressure to make the same boost at the intake manifold. This kills efficiency. I had one rear mount car on the dyno that had an intercooler so small it was making 9psi at the turbo but it was pulling vacuum at the intake.
Engine management. I prefer the stock ECU with HPT speed density operating systems. Awesome driveability and very tunable. Easily keeps all factory gauges and functions. I personally see no reason to use aftermarket unless you need to run more than one injector per cylinder.
Let me start by going back to what I touched on in my other thread. The first and most important decision to make after deciding on a power goal is what turbocharger or turbochargers to buy.
My absolute favorite is the Garrett GT stuff. Yes all other turbos can make similar power but I've yet to experience any faster response then a set of twin Garrett's. I don't build turbos so I don't know of the exact internal differences but I would guess it just comes down to shaft/wheel weight and maybe the bearings.
Precision is also really nice and have been very reliable. We mostly use 7675's and smaller from them. Having driven several small twin setups with both Garrett and Precision turbos I would say the only downside to the precisions is they do not have the insanely quick transient response as the Garretts.
Turbonetics have been reliable but you need to run something that has a fairly well matched compressor to turbine. The TC series 76 and 78 does not fall into that category, IMO. Even in a twin configuration the turbine is just too damn small to efficiently drive the compressor. I would run twin TC67's over twin TC76's or 78's any day. (all with F-trim turbine). As for a single TC, I know people do it but I would not. Why? Because I've driven cars with a single TC76 and I've driven cars with a single 7675. 7675 spools faster and can make a couple hundred more horsepower. More expensive yes but well worth it.
Comp seems to make a quality well built product but from what I've seen needs to build them with a turbine that's a better match for the compressor. I'm sure they can build some awesome stuff but so far they seem to be generating some fairly high backpressure numbers.
Borg warner is in the category of, looks like the most bad-*** turbos I've never used. Would like to try some of their stuff but I can't speak to them with any experience. The EFR series looks awesome- http://www.turbodriven.com/en/perfor...urbos/efr.aspx
Ok, so a few combos. This is going to be pretty basic, not an entire exacting list of what you should buy but more of a general guideline of combos I've experienced and liked.
First on the list is going to be what I think is the ultimate street/strip setup. The almighty Garrett/Tial GT35R in twin configuration. These things have amazing response. Even on a 346 and a manual trans you can practically be into boost before the clutch is fully engaged while pulling away from a stop light at 1/3 throttle. Cruising along in 2nd or 3rd and roll onto the gas as you watch 2 black tracks in your rear view. Along with all of this transient response awesomeness they are still capable of 1000 at the tires. I recommend using the Tial stainless v-band housing. Say, .63 a/r for 346ci and .82 for 400ci, 1.06 for 427. Not cheap but usually parts that are ******* awesome don't fall under the ultra-budget category.
On more of a budget but still want twins capable of nearly the same power? Precision has in their entry level line a 6076E. Rated at 610hp each with a 59mm compressor wheel and p-trim exhaust wheel these aren't exactly new technology but would still make a kick *** twin setup and are only $599 each. I've used some similar turbos from them with a 54mm/Ptrim combo on their V-band exhaust housing and they were excellent with very small packaging.
More budget? I mentioned it in the other thread but an LQ9 with twin stock GN turbos is a blast. 600rwhp and practically instant boost. A few reasons I can't recommend it is the buick turbos are a bit strange and the internal gates won't regulate boost down to a low enough level if you want to upgrade them down the road. If you're putting a swap car together and want a fun inexpensive setup than I highly recommend it.
Not enough power? Ok, another great streetable combo that we've built many of is simply a 408 with twin 6766's, TU2 cam, any decent aftermarket head really, LS6 or LS2 intake manifold, will do 1,150+rwhp and turn to 7700+rpm. LS9 gaskets and studs will live at this level if you're tune is spot on (and you are one of few that actually run the proper octane fuel) but for more reliability I think going to an aftermarket block such as LSX, RHS or ERL with 6-bolts/cyl over 1100rwhp is a very good idea.
You have some strange aversion towards twin turbos? Ok, as much as I really don't like single setups I must admit that something like a 346 and a PT7675 is pretty bad ***. Pair it up with a TU1 cam and it will do a bit over 900rwhp with an M6. Fun combination. Do not try to run 400+ cubes with this turbo unless you want to make about 150 less rwhp and shift it at 5k rpm. This is why it's important to put together a matched combo. Too many cubes on a smaller single like this will turn a potentially great combo into a tractor.
Bigger singles than the 7675? I've driven quite a few of them and none of them are as responsive as I would like on the street, especially with a manual trans. Rolling onto the gas with moderate input kind of leaves you waiting a bit and then a hard midrange hit. Yes they can make a lot of power but I wouldn't personally build one knowing I can put a twin setup together for the same money, same horsepower but faster response. Also, I find it easier to package 2 small twins and their respective parts than a giant single with a monster downpipe.
Journal vs ball bearing. On the same turbo going from journal to BB will not make much difference in logged boost vs WOT. It will still hit peak boost at almost the same rpm. Difference is in transients. Pull away from a stop and roll on the gas, BB units feel more responsive, more of a liquid transition into boost.
Almost forgot about APS! I know many have had reliability issues with the turbos supplied with the system but otherwise I think these are bad-*** systems for a street car. Very capable hp wise and very little lag. If I was going to build a car that an APS system was available for I would strongly consider using it. Not sure what's still out there and available still as far as new systems, to get one you'll probably have to scrounge the classifieds.
Keep in mind that running a very small pair of twins, even something that could hit peak boost by 3k rpm will not choke the rpm range hard like an undersized single.
Rear mount. Yes they can be fast with a stalled auto but again, I would never do it. Seems like nearly as much work and cost as building a traditional turbo setup. I've never driven one that had any good part throttle response and many I've driven just start to come online at the top of each gear (manual trans).
Compression ratios. Generally. I prefer something close to 10.0-1 More for all out race cars and less if you want a bit more room for error before breaking something. Definitely do not recommend anything lower than 9.0-1, starts to feel a bit soggy when not in boost.
Fuel. I like to tune to a reasonable boost/power level on pump fuel (lets say conservatively 10-12psi for most setups) and add or run race fuel above that. I don't trust meth systems enough to rely on them for octane or fueling. If you want to conveniently run 1000+rwhp on the street then dual fuel systems and staged injection works nicely though I don't find it much of an inconvenience to use race fuel when it's needed.
Heads- Like most other aspects of a turbo engine, build it to make power naturally aspirated and it will be that much more efficient on boost. Stock heads can still support a ton of power. Anything aftermarket is going to have a thicker deck surface which will help with head gasket sealing.
Intakes- Not a fan of single planes and the low profile 'Tron' elbows. Would much rather use an LS6/LS7/LS2 intake up to around 1200rwhp or so. The edelbrock pro-flo efi and similar work great but it's really hard to beat a factory composite intake in terms of power potential and overall driveability. Something like a big sheetmetal intake that would kill low end response on a naturally aspirated car will to some point do the same on a turbo engine by contributing to the feeling of lag.
Intercooling. The bigger ebay units are OK. Certainly a deal for the price. For a bit more money you can run a Precision, Bell, or Griffin and they are much more efficient. Precisions "825hp" air to air unit actually supports closer to 1000 and fits perfectly in the nose of a 4th gen while keeping all of the radiator shrouds in tact. (must remove bumper support). For the dragstrip an air to water with ice is unbeatable. Works nice on the street as well but would probably not use it on a car that's a roll racer or sees extended time at WOT. Be careful on going to small with an air to air. A 10psi drop across the core means 10psi more turbine drive pressure to make the same boost at the intake manifold. This kills efficiency. I had one rear mount car on the dyno that had an intercooler so small it was making 9psi at the turbo but it was pulling vacuum at the intake.
Engine management. I prefer the stock ECU with HPT speed density operating systems. Awesome driveability and very tunable. Easily keeps all factory gauges and functions. I personally see no reason to use aftermarket unless you need to run more than one injector per cylinder.
08-18-2012, 04:47 PM
#2
FormerVendor
Thread Starter
Again, realize that all the above is my personal preference so take it for what it's worth. My opinions are based on the fact that I like very responsive combinations. I'm building a 390 with twin GT3076's for my Cadillac because I'm happy to trade max hp potential for ultra fast response. To me that's what makes a turbo car fun on the street because most of the time you are not at wide open throttle.
Ok, enough for now. Any opinions, questions, comments, have at it.
Ok, enough for now. Any opinions, questions, comments, have at it.
08-18-2012, 05:53 PM
#3
Great information!
I hope i'm not being a dumbass for asking this, but what are your thoughts on all the 5.3's running a single s475 with a tu1 cam and a 80e backing it all? Seems like that set-up is becoming more and more popular everyday, and it can be built CHEAP.
I hope i'm not being a dumbass for asking this, but what are your thoughts on all the 5.3's running a single s475 with a tu1 cam and a 80e backing it all? Seems like that set-up is becoming more and more popular everyday, and it can be built CHEAP.
08-18-2012, 06:11 PM
#4
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awesome stuff !!! having owned a small turbo twin setup on a stock 5.7l the response was insane to the point where it nearly caught me out on the street a few times !!!! meaning sideways into a pole type incidents!!!! you learn not to come around corners and go full throttle before car is settled!!!! got a 408ci lq9 now was going to go twin gt3582 turbos but decided to go the big single instead !!!!does have the wait for it type moments but when it comes on fark me hold on!!!! regardless of which setup you decide on they are all good in there own ways and can have the manners of a stocker!!! cheers
08-18-2012, 06:26 PM
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Very interesting read. I was planning on asking you about what you thought about the APS setup and where it falls in your favorites list, and then I saw the nice excerpt. This is my first time running turbos so I was not sure how the system compared to other custom setups with fancy turbos. However I do feel that there is room for improvement as far as transient is concerned. So my plan is to get a pair of cartridges from BilletTurbochargers from Aussie land and leave everything else the same because even in their current form they make great power on my setup.
08-18-2012, 07:24 PM
#7
Good info. That and the Search button. There are MANY detailed and proven recipes for every conceivable application with pictures, video and timeslips to back them up in here. If your idea differs drastically from some of these proven combos, it's probably a bad idea. Specially as it applies to the street/strip cars.
I disagree with regards to the aftermarket engine manage systems. Specially as it applies to 800+ rwhp. Having seen the greener grass, I consider myself foolish for not having done it sooner. You do lose the stock gauges with all the good systems though.
I disagree with regards to the aftermarket engine manage systems. Specially as it applies to 800+ rwhp. Having seen the greener grass, I consider myself foolish for not having done it sooner. You do lose the stock gauges with all the good systems though.
Last edited by 98Z28CobraKiller; 08-18-2012 at 07:30 PM.
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08-18-2012, 07:34 PM
#8
Nice post! I am about to do a BW setup myself... stock 5.3 with dual springs and a cam(not sure which of either yet). Fast ported 102 intake/TB. Fast 80lbs injectors with rail. Truck manifold front mount setup. T6 s472, 1.00 a/r , 83mm. 60mm wastegate.
Im going to make a post when its done and running because its going into a nissan 300zx z32.
Wish you made this post before cause i was dying to do twins and had no clue which turbos to get and a buddy sold me this bw turbo cheap BNIB so went single.
Im going to make a post when its done and running because its going into a nissan 300zx z32.
Wish you made this post before cause i was dying to do twins and had no clue which turbos to get and a buddy sold me this bw turbo cheap BNIB so went single.
08-18-2012, 08:02 PM
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Im curious if you could comment on what would be your ideal parts build recommendtion for a budjet small twin turbo 5.3 build. My ideal situation would be only to have to swap in some larger injectors on a otherwise stock 5.3 shooting for 500ish-550ish hp street car. If I popped a motor just swap injectors on another junkyard 5.3 and not having to break it down to swap cams, ARP bolts,ect....
As much as I enjoy reading all the freakish high horsepower junk yard motor builds, I just want a street only car. And your thoughs on running E85 as well on this type of setup....
Thanks in advance~
As much as I enjoy reading all the freakish high horsepower junk yard motor builds, I just want a street only car. And your thoughs on running E85 as well on this type of setup....
Thanks in advance~
08-19-2012, 10:10 AM
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Awesome post man. I know you love the twin setups and they definitely have their place. I along with alot of guys are running singles, but glad to hear your take on all sides even the rear mount stuff. It puts it into great prospective and seals the deal for me to ditch my tc78 for a PT7675. I already am running a tu1 on a forged 346 with 9.5:1 CR so that turbo sounds like the perfect compliment for an ideal single setup.