After reading a post by jimlab about the possibility of using Supra twins in an FD, I decided to start a new thread and see if this has been tried or discussed before. Below is Jim's quote:

I did a quick search and found that it seems that Toyota used the Hitachi CT12B turbocharger(s) in the Supra. http://www.geocities.com/MotorCity/P...ochargers.html

I found this compressor map which seems to indicated that it is for a CT12B by the title:


Feel free to discuss this topic. I am interested to see what kind of feedback it gets. A few initial questions/observations I had include:

1. Are Supra twins sequential?

2. Has this ever been done to anyone's knowledge?

3. What all would be involved? I would think at least:

• Some kind of adapter plate for the exhaust manifold
• Oil Lines
• Custom Y-Pipe

Food for thought...

 

not worth the time and money involved, anything can be done with enough money though.

 

^ okay.....very informative, where's my wrench?

to answer your question, they are actually 1mm larger than rx-7 turbos, it's not worth the hassle, i researched it a while back....

 

That compressor map is for a Garrett T3.

 

For the money spent might as well go T78

 

They are sequential. The merits of swapping seem minimal. So what if they flow more on the 2jz so can most singles apparently. I see average singled Supras running 25psi+ on T78s and average FDs hovering around 19 or 20psi.

 

ur better off with a 99 or BNR twins than that IMHO

 

black about supra singles running higher boost...its not the turbos that is the limiting factor on the FDs. Those guys run 15lbs w/o even upgrading their fuel.

 

Yup, what batman said. As I have posted before, the exducer on both compressor wheels are a full 5mm larger than stock on the new BNR twins. I think it's a lot of time and effort for questionable gains.

 

In addition to what you said. Supras can make 500-550RWHP on stock fuel, its quite ridiculous. On stock twins/fuel, a typical BPU Supra with a BCC will run around 18psi. Their twins seem to be very robust in their abilities to handle high boost, more so than the stock FD twins.

 

Yes supras do run higher boost than fds even on same turbo there is a reason however, Rotarys have a much better volumetric/ehxaust volume effiency than the equivilant piston motor, thats how we can run such a large turbo *t78,88, t51 ect ect* on a 1.3 liter.

 

Pianoprodigy, I like the idea a lot. It's something that I've been throwing around in my head for a bit too... An adapter plate for the manifold isn't gonna cut it...you need a custom high-flow manifold (see below), flanges for the twins, and the stock Supra y-pipe, and somehow fabricate connections to our piping.

On the sequential thing...maybe Jim can answer this better, but from my limited knowledge, the MKIV Supra's twins aren't a true sequential setup, correct? The spool pattern is a little diff from our twins, no?

The merits of the swap seem quite considerable IMO. Before you go on talking about a single and large hp #s, a lot of people love the quick spool and LOW END power you get w/ twins...plus that second kick you get w/ the sequentials. Now imagine making #s equivalent to a large single on sequentials at fairly low boost?? To me, that would be making the FD what it was SUPPOSED to be.

I disagree w/ you...the FD has several limiting factors:
- General unreliability of the rotary: this one has to be taken into account, since I'm very curious how a 13B-REW would handle making 500hp.
- Flow of the rotary: It's not as efficient as a piston engine, and thus the #s you can get w/ say, the 2JZ are 10% - 20% greater than what you can make w/ an FD. You can try to even it up w/ porting, so the engine flows better...which brings us to the next point...
- The stock turbos: while they're definitely capable of flowing more but can't due to backpressure from the crappy and restrictive stock manifold, the stock twins can only handle so much. Even w/ a very flowing manifold... They're spinning at such high rpm as it is at stock and close to stock psi...I don't think they could handle much more. So they're definitely a limiting factor.
- The stock exhaust manifold: it's VERY restrictive. As Rich has told us (in his dyno thread), the stock manifold is good for only about 420hp. The Supra's runners & manifold are so well designed for high flow, which makes a huge diff. in the hp #s those turbos can make.
- More flow issues: hp = rpm * torque / 5252, no? So the more torque you make at higher rpm, the higher the hp. In fact, making lots of torque at high rpms is crucial to getting serious #s (like the Supra's 500hp). Not only do our twins usually run out of their efficiency range at such high rpm, but also the stock UIM becomes an impediment to flow, right around 6250 - 6500 rpm. That's why Demetrious went w/ a custom UIM, if I'm not mistaken, which explains his beautiful torque curve...
- Fuel: the fuel system on the FD is a very weak link, in reference to the hp #s people often are trying to make out of them. But this is easily fixable...as there are all sorts of upgraded fuel rails & injectors, hi flow pumps (even running 2 pumps), FPR, etc. If anything, I think this is the easiest to fix, since lots of FD guys have invested so much into it anyways...you can easily get a fuel setup to handle 600hp+...

Rich, while I see your point, and I honestly believe the BNRs hold great promise, I'm not gonna put my money on either until another dyno run is completed, at normal air temps and at higher boost. Oh and keep in mind, you may be capable of making more hp on the twins, at lower boost too, but the stock manifold is STILL gonna limit that...it's a problem no matter what twins you have (esp. if you're sequential).

If I'm wrong about something...my bad (still a Newb lol ). So feel free to correct me.

~Ramy

 

It's true that rotary engines produce high exhaust temperatures and therefore a lot of exhaust energy for their size. However, the 2JZ-GTE displaces 3.0 liters, and the 13B-REW displaces (in comparison) 2.6. That alone is explanation for the difference in boost level. The 2JZ-GTE can ingest more air per cycle and is more efficient at producing power with it.

 

Interesting, there happens to be an exra set of Supra turbos only feet from my FD turbos, seeing as how the engine is being rebuilt and all. Fwiw, the whole system is a fair amount bigger, I'll try to get a pic this weekend if I head out that direction. Josh

 

Josh, def. post pics plz if you get a chance.

Jimlab, any word on the sequential nature of the MKIV Supra twins?

Oh and Rich, I forgot to mention...don't the new BNRs only come parallel? If so, the Supra twins seem like a very good option for die-hard sequential fans, unless Bryan is willing to make the new BNRs sequential as well...

 

Yes, they are, and not substantially.



Actually, like the MAF-sensor debate, the same amount of effort and money would be better spent on a single turbo setup and improved fuel management.

A small "street" single, especially with ceramic ball bearings, can spool as quickly and make "low end" power. Unfortunately, most people are caught up with bragging rights when they go single and they end up sacrificing part of the rpm range for big peak numbers.

There are (or were) simpler aftermarket twin turbo setups available from Japanese vendors for turbos like the TD05, etc.

They'll manage it, especially with an upgraded fuel delivery and management system, but people think making the power is the end of the battle. But pushing an engine that made ~255 horsepower stock to double its output takes an eventual toll and absolutely shortens engine life. Much more so than, say, a ~405 horsepower LS6 asked to produce only 100 horsepower more... which will deliver better gas mileage while doing it.

 

Does it make sense to pursue this possibility?

1. Which has higher performance potential (based on turbo characteristics)? It would seem that the BNR turbos are larger and could thus flow more than the Supra turbos.

2. Which costs less? Even if you can get a stock Supra sequential assembly cheap, I would expect the costs of adapting it to work on the FD to exceed the price of a BNR upgrade set.

I don't see the sense in it. That doesn't mean I don't think it is an interesting idea; it just seems like better options are already available.

-Max

 

They'll manage it, especially with an upgraded fuel delivery and management system, but people think making the power is the end of the battle. But pushing an engine that made ~255 horsepower stock to double its output takes an eventual toll and absolutely shortens engine life. Much more so than, say, a ~405 horsepower LS6 asked to produce only 100 horsepower more... which will deliver better gas mileage while doing it

ha....the obligatory LS6 comment find it's way in there

all I can say is, Toyota engineers make their Mazda counterparts look like imbeciles....the bs you have to put up with FDs is just amazing....if wasn't such a light weight and good looking car, no one in their right mind would bother

plus the "smoot" on the rear bumper, ha

 

it just seems like better options are already available

sure....buy a MKIV Supra and live with the extra fat

I still can't believe Jim sold his car for 17k.....the buyer got the deal of a lifetime

 

I believe you about it's capabilities, but as to whether it's money better spent, I'd have to drive it and get a feel for it before deciding...

Huh?? You mean parallel aftermarket twins, right? I've never heard of an aftermarket sequential twin turbo setup...(which of course doesn't mean it doesn't exist...)

 

there was aftermarket sequential twins, but they were bascially high-flowed stockies.

 

Yes. Believe it or not, there are people who don't give a **** about having a sequential configuration...

 

I havent heard of Supras getting over 500 engine hp out of thier twins. If this is the case then you'd spend a LOT of money converting those to a FD and more than likely make LESS power. 500 engine hp on a supra converted to a rotary car would be around 450 or so. Then convert to the wheels and your talking 382rwhp which is pretty common for out cars with OUR twins.

I cant find any reason that anyone would want to run Supra twins on thier car.

 

430 at the rear wheels is 500+ flywheel horsepower and there are many BPU MKIVs in that range. In fact, I know of at least one car that put down 485 RWHP with the stock twins... on a Mustang dyno. I've seen Chris run several times and barely missed running against him in the finals at the 2000 NIRA Northwest Nationals.

http://www.mkiv.com/mkivregistry/rea...ann/index.html

http://www.mkiv.com/videoarchive/avi...U11_63@123.mpg

Name the FDs making 400+ RWHP on stock twins.

****, here we go again. More of your home-brewed "car math", I presume?

Riiiight... really common.

Personally, I'm surprised you can put your own pants on without help, but hey, the world is full of surprises.

 

LOL...Jim, trust me, I know a LOT of people who don't care for the twins...in fact, that's the first thing they ditch when they get an FD... I'm just not one of them.


Really?? Who made 'em? You're not talking about the BNRs, are you? Or the twins someone had reworked by TEC? I don't remember if the TEC and M2 twins were sequential tho...

Jim, you obviously disagree w/ Stephen on this.
1) 485RWhp??? WOW...this on a stock engine and fuel system too?
2) So what do YOU think the #s would translate to (roughly) w/ the Supra twins on an FD? Lets say, using 450rwhp as very doable on a Supra....

EDIT: I just read the link....HOLY.....Stock engine, stock twins (at 23 psi lol), stock ecu?? Basically he's just running intake and exhaust...MAN...that's incredible.