7m-gte twin turbo

[supra 7m-gte]

hi everyone.......


I wonder if anyone tried to make 7m-gte from single turbo to twin turbo and he could run

is it a good idea


but I saw images for 7m-gte twin turbo but Iam not sure if it is reliable or not.

if anyone know how to make it twin turbo, please list the requirement .

[TcmaBoy]

Well, all you would need to do the conversion is a pair of turbos and a manifold to go with. The question is; why would you do the conversion?

[repinS]

Before you get all giddy, know that the logic in which two turbos are twice as better compared to one isn't true.

They serve different purposes. Speaking of which, moderator Bob Grieger has a twin manifold for the 7M, haven't heard much about it lately

[bgrieger]

Originally Posted by repinS

Before you get all giddy, know that the logic in which two turbos are twice as better compared to one isn't true.

They serve different purposes. Speaking of which, moderator Bob Grieger has a twin manifold for the 7M, haven't heard much about it lately

Progress continues...too many things compete for my time...like working to pay for it ;D. Still need a few parts, and the time and cash to rebuild the engine.

yes, it's been done. The theory and rationale is that the twin turbos spool somewhat faster than singles at the low end, but are also somewhat less efficient for those seeking peak power. Not to mention of course, at double the price or more, plus the headaches of plumbing it, singles are a far simpler way of doing it. I'm not a simple type of person, and I want all the power as fast as possible, so I want my twins.

I'm pitching the manifold as well...that one needs too much rework to suit my needs. I'm going to pick up another TT manifold in the coming weeks that will in the end cost me less than fixing the one I have. Live and learn.

Bob

[repinS]

I remembered at last year's autoshow you said the whole freaking flange was warped... too much to fix, eh

[supra 7m-gte]

everyone ask me why I want to make my 7m-gte twin turbo?

the answer is simple :because I want to show everyone in my region the true power and efficiecy of the 7m-gte.

[supra 7m-gte]

finally I found ths images for 7m-gte twin turbo

[bgrieger]

That appears to be a kit made from CT12's borrowed from a MKIV. They should do 400, but a lot of effort to do it, if you don't know how to weld.

[bgrieger]

Originally Posted by repinS

I remembered at last year's autoshow you said the whole freaking flange was warped... too much to fix, eh

3 problems with it. The main flange is banana shaped, the pipes don't line up with the holes (sagging) and the turbo flanges have to come off as there are far better turbo options than Greddy. The replacement should only need the greddy flanges replaced rather than reworking the whole thing, and that's reasonable. The original I have appears to be the result of welding without a jig...heat warps.

[2wickedtoyz]

i remember reading about a guy building a turbo kit like that but the problem was the turbos(2x t25/t28 garretts) didn't spool until 4200rpm's. he later realized 3 cylinder producing only 90cid could not deliver sufficient airflow to drive larger turbos at low rpms.

the bends were very smooth and the turbos were staggered but it wasn't practical.

if you can setup a system to make it a dual stage arrangement in that one turbo spools up early in the rpm range to boost bottom end power. at a predetermined threshold, a flapper valve brings the second turbo online.

[TcmaBoy]

Originally Posted by 2wickedtoyz

i remember reading about a guy building a turbo kit like that but the problem was the turbos(2x t25/t28 garretts) didn't spool until 4200rpm's. he later realized 3 cylinder producing only 90cid could not deliver sufficient airflow to drive larger turbos at low rpms.

the bends were very smooth and the turbos were staggered but it wasn't practical.

if you can setup a system to make it a dual stage arrangement in that one turbo spools up early in the rpm range to boost bottom end power. at a predetermined threshold, a flapper valve brings the second turbo online.

He had problems with a twin T-25 set up? Thats odd, those are rather small turbos. A T-25 should be comparable to a CT-12. I know that there is a twin T-3 kit out there for the 1JZ, I think HKS makes it, which is a half a liter smaller than the 7M. The T-25 should have been a good match. I wonder if he had the wrong trim or something.

You have to keep everything small. Just having a small class isn't good enough. You need the small version of the small turbo to make things work. I think you would want either a T-2 on the big side or a T-3 on the small side. I know its a crappy way of putting it, but my brain is fried right now and I can't think of better terminology.

[2wickedtoyz]

i think it was also the fact that those didn't hit constantly

ie: if it was a 3cylinder car there would be constant pulses going into the turbo but it was a 6cylinder using half of itself for one and the other half for the other turbo. so the pulses weren't constant

[bgrieger]

Yup. GT28R turbos come up to full before 4000 on the 1j...the 7M should have them fully spooled in the low to mid 3K range...very similar to the CT26 with a huge upside! He may have selected too large an exhaust housing.

[TcmaBoy]

Originally Posted by 2wickedtoyz

i think it was also the fact that those didn't hit constantly

ie: if it was a 3cylinder car there would be constant pulses going into the turbo but it was a 6cylinder using half of itself for one and the other half for the other turbo. so the pulses weren't constant

It is true that you do need to consider firing order when building the manifold, but half and half should work. That is how the turbos are mounted on the 1JZ. You have two very short manifolds. One on the front 3 and one on the back 3. The short part is important. The exhaust gas only has to travel about 3 inches to hit the turbo. You get the full advantage of pulsation effects. If he was using some sort of long runner system that may have caused some of the trouble.

[Jeeves]

1/2 and 1/2 have worked for many many aftermarket tuners/companies on the 7M the 1JZ and the 2JZ. While that 1/2 and 1/2 setup above is interesting looking it's definately far from the best design I've ever seen.