Single T or TT

The twin turbos on a supra run at 8psi promary and 11psi secondary am i correct?

when you get a boost contol do you only need one or 2 for individual turbos? or do they both bost up with one control and how so?

Which is better single or TT? TT has less lag and the secondary give the top end, but the single turbow give more top end power but some turbo lag? wich set up is better and why?

Whats the stock A/R size on the twin turbos and whats the A/R size of a single turbo supra...

Were most supras made with twin or single turbos? and how can you tell which are single and wich are TT without looking under the hood?

what can stock turbos run? up to 15 psi? and what can a stock supra engine produce? about 400-500 hp?

im just learning about supras and im looking to buy one sometime next year 93+

lots of questions young grasshopper, lol sorry couldn't help myself. OK. The TT setup runs on a sequential setup where as one turbo works, then the secondary works after it. You can run them in a parallel system which is they both come on at once but very laggy. On which is better, a TT or single, it really depends on what your wanting to do with the car, I prefer a single, but a quick spooling turbo, it creates more power without as much lag off the line, which is optimal for running 1/4 mile runs. There really isn't a way to tell if a car is a single or twin turbo setup without looking unless it's a promod car with a big turbo sticking out of the hood. On a twin turbo setup, you can run up to 18psi safely and 21psi on race gas (ex. 116 octane) A stock supra turbo motor (2jz-gte) can produce in the range of 800-1000hp (with the supporting mods such as a fuel system, turbo, etc.) and that is on stock internals such as the pistons, rods, etc. If you have any other questions, feel free to ask on here, I'm not sure about the a/r sizes but I'm sure MKIV.com will have that information for you, if not I can get it out of my manuals and mail it to you if needed. Good luck on finding your car :) Later :)

lots of questions young grasshopper, lol sorry couldn't help myself. OK. The TT setup runs on a sequential setup where as one turbo works, then the secondary works after it. You can run them in a parallel system which is they both come on at once but very laggy. On which is better, a TT or single, it really depends on what your wanting to do with the car, I prefer a single, but a quick spooling turbo, it creates more power without as much lag off the line, which is optimal for running 1/4 mile runs. There really isn't a way to tell if a car is a single or twin turbo setup without looking unless it's a promod car with a big turbo sticking out of the hood. On a twin turbo setup, you can run up to 18psi safely and 21psi on race gas (ex. 116 octane) A stock supra turbo motor (2jz-gte) can produce in the range of 800-1000hp (with the supporting mods such as a fuel system, turbo, etc.) and that is on stock internals such as the pistons, rods, etc. If you have any other questions, feel free to ask on here, I'm not sure about the a/r sizes but I'm sure MKIV.com will have that information for you, if not I can get it out of my manuals and mail it to you if needed. Good luck on finding your car :) Later :)

thanks for reply the old mighty wise man! :) wow 800-1000 on stock internals!!! #$#@#$@ now i want one bad!!! my 240 can only handle 400 on stock internals and i thought that was huge power hahaha.... never knew supra engines are so strong stock....

I did notice that most supra owners have single turbo, is it because they upgrade to single turbo or is it because they made more single turbo supras or TT supras?

You said its safe to run at 18psi, now is that on primary turbo or secondary turbo? and is there a way to adjust both differently or they both adjust by one switch to different PSIs? and what would be approximate hp running stock engine with stock turbos at 18psi?

you said the parallel system, its not stock this way on a twin turbo am i right? so why would someone change that to a parallel system and get more lag? do they gain more top end power?

Honestly im not gonna do much with the supra because they are fast as heck stock with a turbo... so i dont think i will be upgrading turbos no matter if its single or TT...

I was going to put a turbo on my 240 and rebuild the internals and be happy with a 13 sec car... but since i live in CA and greddy doesnt make a turbo thats CARB legal so that would suck if i got my car impounded... so i was gonna build up my own turbo and hide it as good as possible, but it will still be risky you know what i mean? and i just wont enjoy driving my car everyday being all illegal and me being all worried about cops every where i go... i want to actually enjoy driving a fast car and be perfectly legal, and supra is the only one of a kind :rolleyes: and ill pass smog and inspections, and will be good to go and have the power to play with.

hmmm dont no much about the supras but 93+ is the new body styles right?? i say good luck finding one and with all the money you put into buying a stock supra a 240 would waste it. thats just me though. But a supra definently has hecka more potential. Maybe i miss understood you, it sounded like you want just a stock supra with no mods??? But a supra isnt cheap. Yes there fast stock but there not that fast stock. I mean you'll still run into your comaros and stangs that can easily beat a stock supra. I say stick with the 240 to be honest, not to mention the insurance rates on a supra.

Turbos don't work like your thinking. If you have two turbos flowing say 15lbs at 5psi, that doesn't mean a total pressure of 10psi. It means you're flowing 30lbs at 5psi. Exactly why a small turbo will not make as much power at a given boost level as a larger turbo. I believe the thing on the sequentials is one turbo is efficient at a given flow and the secondary is efficient at a higher flow. Or they use some kind of bypass system. i have also heard that one turbo is more efficient than two. Not sure on that one though.

If you can get your hands on a supra, I would go for it. Supras are teh sex, but I mean you'll never have to upgrade internals. Not to mention the millions of parts, HP potential, and they have pretty good handling and great braking.

the good
supra = sexy
supra = Fu$Kn fast (turbo!)
the bad
supra = fat
supra = not nimble
supra = $$$$ (not for power, just the cost of buying one)
supra = $$$$ to fix anyting

I'm pretty sure all MKIV Supras were either twin turbo or no turbo. Only the MKIII (or earlier, I dunno) came with single turbo. Single turbo MKIVs must be a mod.

like flyinMKIV said, Single Turbo is better for 1/4 wise and twin turbo is better for the topspeed, especially when you have 2 T78 TURBOS IN A SUPRA!!! hahahha...has any ever done that IN a street Supra?

Id get a 300zx twin turbo before a Supra as far as pricing goes, and they are both nice cars

Here are the reason why im looking into buying a supra...

1.Turbo stock, so passing visuals and no need for CARb sticker like putting a turbo in a 240... greddy doesnt even have a CARb for them yet!! so i wont be turboing my 240 anytime soon probably never...
2. runs 13.5 1/4 stock
3.No internal work needed to gain massive amounbts of HP
4.Straight six not V6, so more room to work on and less complicated
5.just sooo sick looking haha...

the price part is what ill have to look around for, im looking at about $15k if im lucky...i will be replacing rings and rod bearings if high miles on it...

by the way anyone know how reliable supras are with turbos? because i know cars like eclipses that come stock with turbos dont last more than 70-80k because engine has lots of stress on it...

If I remember correctly the stock MK IV turbo system was a sequential setup. It used a bypass and wastegate control to divert exaust flow to the turbo that needs it. At low engine speed most of the flow is diverted to the small turbo to spool it quickly. As it reaches peak flow is diverted to the larger turbo to begin spooling it. The two are matched so that as the small turbo is running out of breath the large turbo is spun up. Exaust flow is cut to the smaller turbo so as not to exceed its limits. It delivers the best of both worlds. The only problem is it is complex. Parallel twins are simple, and offer better low end boost. You can use small turbos togeather to deliver the needed volume. This gives good low and midrange, but top end is limited. A large single turbo will give the big HP numbers but you will need to wait untill about 3500 RPM to see any power. I belive the boost controllers for the stock MK IV turbo system affect both turbos equally, but I'm not sure. They usally work by modifying the boost reference signal to the wastegate actuator. You can milk over 400 HP out of the stock turbos with a little tuning. I'm not sure how carb feels about piggy back electronics, but they are way too easy to hide in they don't like em.

I saw someone said that supra=not nimble. HA! I have seen plenty of articles on MK IVs pulling 1.0G+ on the skid pad. Thats supercar grip my friend. Not to mention the Supras dominance of the JGTC for the last decade or so. Thats a field that includes not only Skyline GTRs, but there are also a few McLarens and Ferraris in the field. Supras stick.

how much can a stock TT supra last mileage wise? lets say its an average driver and oil has been changed when needed to be changed... how reliable are they? can they go over 100k with no problems? 200k possible? ... i know toyotas are made to last and outlast all the cars, but how true is this statement for the supras?

at what milage would it be a good idea to replace the rings and the rod bearings? 100k+?

It should last at least 130000 miles, unless you really abuse it.

so lets say i get a 130k miles turbo supra i should probably put new rings in and rob bearings and bore it .20 over, or dont bore just do the rings with bearings?

what u guys suggest for a high mileage TT?

stock turbos tend to last about 100k for a new rebuild or upgrade, it depends on how they have been treated. MKIV Supras only came as a non-turbo with ethier a auto tranny or 5 spd and the twin turbo supras came in ethier a 6 spd or auto tranny as well.

You also have to remember that singles are about 2-3% more effecient over twins as well.

You also have to remember that singles are about 2-3% more effecient over twins as well.

how so?

who said eclipse with stock turbo dont last that long? its not true... i've been abusing my eclipse since i bought it (2 months ago when it was about 104k) now its at 107k miles.. turbo still spools strong and fast. Im gonna have Mitsu replace everything in need to make my engine last for another 2-4 years during late jan or early feb 05

how so?

I stand corrected.

You know, it really sucks when you see something posted some where on another site, and take it for gosple. I saw that singles were more efficient on one of the Skyline sites I go to.

Well, I should have picked up my Corkey Bell book, and read up on it again, my bad.

Yes, twins are more efficient.

It's not really a matter of efficiency, rather what is efficient for you. If you want to have a great 1/4 mile time, it can be done on a twin setup or a single setup. If you want high top end numbers, it can be done with both as well, it's just a matter of what you really want. Being into supras, I know that it's easier to do what I want to do on a single turbo setup rather than a twin turbo setup. It's really what you want to do. What do you want out of your car?

Right, matching the compressor map with the displacement, and rpm power band that you want out of the engine. But with that being said, it easier to spool two small turbos, than one big one.

I know you guys will go to the singles, so you can do away with the sequential. To tell you the truth, I don't recall seeing any Supras running big numbers with twins, I am sure they are out there

It's not really a matter of efficiency, rather what is efficient for you. If you want to have a great 1/4 mile time, it can be done on a twin setup or a single setup. If you want high top end numbers, it can be done with both as well, it's just a matter of what you really want. Being into supras, I know that it's easier to do what I want to do on a single turbo setup rather than a twin turbo setup. It's really what you want to do. What do you want out of your car?

well i dont want a car that will go through the 1/4 without lagging from start and without toping out at higher RPMs.. its picking the right side for less lag and for top end thats sometimes a hastle so from what i heard is on a TT turbo set up the smaller turbo spools fast from start and then it goes into the secondary bigger turbo to keep the power coming at the higher RPMs without toping out, so it seems like the TT would be more efficient for a 1/4 or stop light to stop light races because it would have less lag, but if i was to go for the speed i would definetely go with the huge turbo and build up my engine in and out to spool up that huge turbo faster and and then engine being strong enough to keep up with the huge turbo after it start spooling...

you are right its all about what you want.. and nobody wants turbo LAG or toping off at 5k either... it seems impossible to get both sometimes out of one turbo thats why TT sound sbetter for delivering both.. no lag and doesnt top out because its supported byt a bigger secondary...

i never got into TT yet, still have lots to learn about single Ts and the sizer and trims and all that stuff, but every time i ask and read and look into it more i get more info... thanks guys

To run an optimal drag race, you should never have to leave third gear and you should befinishing the quater mile at the same time your hitting red line.

The thing about twin turbo setups on supras is that it's just plain flat out a pain in the ass to fix when something on it goes wrong, too many vacum wires to check, my single turbo only has 3 or 4, not too much time is spent on diagnosing the problem. Running a small aftermarket turbo is sounding like what you want. Run twin T-28's and you should be fine

To run an optimal drag race, you should never have to leave third gear and you should befinishing the quater mile at the same time your hitting red line.

The thing about twin turbo setups on supras is that it's just plain flat out a pain in the ass to fix when something on it goes wrong, too many vacum wires to check, my single turbo only has 3 or 4, not too much time is spent on diagnosing the problem. Running a small aftermarket turbo is sounding like what you want. Run twin T-28's and you should be fine

thanks... what turbo u running and u go the 1/4 minle and whats your hp ans what upgrdes u have if u dont mind me asking... thx

My new setup that is being built at the moment and is projecting mid to high 11's. I have seen plenty of my friends who drive supras break carbon fiber drive shafts completely in half which is way too much power, and the sad thing is is that they never broke past 12 seconds at the track. It honestly depends on what you want to do with your car. There are a few cars out there that can compete in just about every type of car event. But the owners have invested a lot of time and money in their cars. I decided not to go that route quite yet, rather just be a good 1/4 mile and interstate car. I have several turbos which throws my setup around on people because they never know what I'm tuned for. Best way to make money in my oppinion. But if you want your car to be a good all around car, check out several different sites about turbos and do your research. Taking someone else's setup is not bad but it's still not exactly what you want your car to do, it's what other people wanted their cars to do. Do your research and when you've made a decision, we'll all be more than happy to help you with it. Good luck bro.

Its one thing to have 700hp, but its totally different to having a usable 700hp. IMHO you want a nice broad power band, I guess the Supra guys have leanred form the past mistakes when it comes to this. I mean, I have seen a lot of the older Supras running 700-800hp, but it was not usable because of how the power came on, all of sudden. That is the biggest problem with big singles.

i dont think i want a crazy power supra here in Cali then ill never pass Smog , and that is why im getting a supra because they are stock with turbos and run nice HP and pass smog with no prob...

so im limited to what i can do, i do know greddy probably makes a upgrade turbo kits for the supras that are Carb legal so that can be my second option, my first option would be to rebuild the engine depending on how many miles the car would have and how good it runs when i get it.

I was thinking maybe just rebuilding the engine with stock parts but new parts, like rings and bearings and ill be good for another some 10 years or so with stock power... or im thinking if im gonna be taking the engine apart i might as well upgrade to stronger rods and pistons while keeping the same 9.5 compression... (i dont remember the stock compression)

since the stock engine can hold up to some 800hp with bolt ons i dont really see a point of replacing the internals with stronger parts because i dont see myself running 800hp haha.. probably 500hp is the most i would do

so my question would be is, since im not looking for crazy HP would it be better for me to just replace the rings and bearings and possibly head bolts and rod bolts and crank bearing and keeping the engine stock parts..or might as well upgrade the internals to the next step up from stock?

a bore might have to be done depending on the cylinder walls, but i dont know if i want to go through all the trouble of pulling the engine out, i would just rebuild the engine while its in the car... i have done that on a few cars, dont know how hard it would be in a supra, but it wasnt that bad in other cars..

im not going to be picky if the supra ill get is a single T or a TT so ill pretty much be stuck with which ever one i get... and ill probably keep the turbos stock, or get them rebuild or just get a new pair of new ones that are the same size about as stock, maybe slightly bigger... se i cant do huge turbos because im in Cali so smog regulations suck here.. but ill worry about all that once i get one... they are harder to find than i thought.