Duel turbos?

[nb07bcar]

I was wonder. HAs anyone thought of putting duel turbos onthe ka-t. What I mean is taking and seperating the exhaust and putting 2 exhaust ports to one turbo and the other two to another. I don't know if this is possible. It might not be enough exhaust to run the turbo. But anyway. The first turbo is a small tubo that spools fast, the second turbo is a larger turbo that take awhile to spool. Run a wastgate on the small turbo so it doesn't exced its efficancy and then run them into one intercooler. If it all works out you could have the small turbo make 10 psi fast and then the big turbo take over and run you up to 25 psi. Just a thought. I don't know if the turbos can be run that way? I was also thinking that if you take the exhaust from the small turbo and run it back into the large turbo it might work better.

[S13FREEAAK]

http://www.ka-t.org/forums/viewtopic.php?t=7446

[nb07bcar]

thanks, but it doesn't have an update if it worked well or not. but thanks for the site.

[Chezedik]

It will be nice with a pair of T25s, but a LOT of trouble! With low boost, it will pull like an MF. Also, it will likely solve the problem with the KA running out of steam with a T25 (since there is a lot of room to spare for exhaust). But why, really? To be different. Yes, you would be, and equally cool. But did I mention that piping would suck? If I didn't: PIPING WILL SUCK!!! Also, working on the engine will be nearly impossible w/o removing the system. I understand the whys, but you have got to understand the why-nots.

[Chezedik]

Also, that is exactly what they did on the Supra and RX7, with two turbos. In both cases, people find the cars faster with just 1 large turbo. But it would feel pretty sick! Also, with a large enough external on the small turbo, it should work reasonably well.

[UcantDrift]

The only reason you want twin turbo is because it sounds cool to your friends.

Supra's and RX7's were sequential twin turbo's.

Just get a single turbo matched to the power your wanting and go from there. Easier, cheaper, less fabrication and you only have to worry about supplying and returning oil to one turbo.

The Garrett GT series turbos offer great responce with high end HP, the new compressor wheel and center cartridge designs are tons more efficent than 10 years ago so you can run a bigger turbo with less lag than back in the day.

[toki]

personally, I'd like to see two turbo duel on a KA.

[C-Kwik]

Also, that is exactly what they did on the Supra and RX7, with two turbos. In both cases, people find the cars faster with just 1 large turbo. But it would feel pretty sick! Also, with a large enough external on the small turbo, it should work reasonably well.

I hate the term sequential turbos in this context. Unfortunately, it sounds cooler than the staged turbo set-up it really is. Both the RX-7 and Supra use 2 of the same size turbos, making them a parallel twin system. They essentially block off airflow to one turbo in the low RPM mode and then a throttle opens up to the second turbo allowing both to spool alongside each other. It does not switch from one turbo to the other.

The advantage here is that during low airflow, the single turbo is in a better efficiency portion of it's operation. but as airflow increases, the turbo would normally become inefficient. But by introducing a second turbo of the same size, you essentially split each turbo's airflow in half, allowing the turbos to be more efficient overall.

However, having dissected to Supra TT systems, I will say the efficiencies of the parts around the turbo are quite poor. The Manifold is basically 2 log mani's connected by a flex tube. The runners are rather small and restrictive. There are a lot of very tight bends. The turbos are a bit on the small side as well. Toyota Engineers did a great job putting this package together, but I'd have bet they would have liked more room to work with in the engine bay to free up some airflow. We did put a single turbo on one of these Supras and between the tubular mani and the large turbo, we pulled out 450HP at the wheels with only 2-3 psi. We would have done more but my buddy was too cheap to invest in a working boost controller. In either case, 200 or so HP at the wheels with only 2-3 more PSI says a lot about how inefficient the system was overall. If space wasn't an issue, I'm sure similar power levels for boost could be attained with minimal lag with a sequential set-up. But in the end, space contraints are going to be a limitation here. For all the trouble, A single larger turbo with well thought out plumbing probably could have yielded the same power with a very small hit, if any, of lag.

[UcantDrift]

The stock twins record on a supra is a 11.12 @121.9 which is pretty good for that.

I would say on a larger single turbo that 450 HP would be a lil higher than 2-3psi.

A Supra owner being cheap? Get out of here

[C-Kwik]

The stock twins record on a supra is a 11.12 @121.9 which is pretty good for that.

I would say on a larger single turbo that 450 HP would be a lil higher than 2-3psi.

A Supra owner being cheap? Get out of here

11.12 on stock turbos would be under a lot of boost.

Oops, I had meant to say 2-3 psi more than stock.

Well, all the parts for his car were used except an S-AFC that he put in. But he was cheap enough that he sold the car before dishing out the money to smog it illegally....

[95_240sx]

The only reason you want twin turbo is because it sounds cool to your friends.

Supra's and RX7's were sequential twin turbo's.

Just get a single turbo matched to the power your wanting and go from there. Easier, cheaper, less fabrication and you only have to worry about supplying and returning oil to one turbo.

The Garrett GT series turbos offer great responce with high end HP, the new compressor wheel and center cartridge designs are tons more efficent than 10 years ago so you can run a bigger turbo with less lag than back in the day.

Since when are supras sequential? RX7's are sequential, and both turbos are NOT the same size! Supras are TWINS!

Rick

[C-Kwik]

Since when are supras sequential? RX7's are sequential, and both turbos are NOT the same size! Supras are TWINS!

Rick

MKIV Turbo Supras have always been sequential.

http://www.lextreme.com/sqtt.html

And 3rd Gen RX-7's have always been twins.

http://www.autosportracetech.c...Specs

http://www.turborx7.com/turbospecs.htm

[toki]

FDs are sequential...

[WDRacing]

The JGS guy on that forum whoever linked is an idiot. Running a twin setup and then usi8ng a T3 flanged turbo as the "big" turbo is retarded.

The simple answer is the same one we give EVERY time someone asks this question. Twins on a 2.4 liter motor is a bad idea. There a couple threads about this already, start looking there.

WD