OK....I'm looking for the best configeration for a race type setting; that is, track oriented, not drag.

SO far I've come across the Apex Isamu Rx6, the Greddy T-78, the HKS T51 KAI (Garret in disquise?)

Anyone know of any other set ups?

 

Talk to Max Cooper, he races often and is running the Apexi RX6. Another good choice would probably be the T0S4 from XS. I think the T-78 would be too peaky and laggy for road racing.

 

ok, thanks

I wonder if the HKS T51R KAI would be the same way as the T-78....

I've been looking at super fixed up 7's and I'm seeing 20B rotories fixed up with twin turbo applications, such as the HKS GT3037S's, and also parallel twin Hitachis that apparently boost simultaniously.

 

Right, but most of those cars are drag applications only. For circuit, probably a T04S/R should definitely do it.

 

hrm...it would seem to me that a bigger Single Turbo would be better for drag and two smaller twins better for circuit

 

The parallel twin hitachi's that you are seeing on the 20Bs are they the stock turbos converted run parallel? I am guessing probably so. You probably wouldn't want 20B even with stock turbos converted to parallel for road racing.

A T51 KAI, T78, T88, etc are all way to big for road racing in my opinion, although some people say they can get their T78 spooled by 3500rpm's the other two are definately too big for road racing and are more drag racing turbos.

jspecracer7 had good reccomedations for turbo's. Also the Apexi kit like you mentioned would be a good road race kit.

The bigger turbos will have alot of lag, and be more top end turbos to flow alot of air for serious motors with big ports. Also alot of the bigger turbos like the T51KAI once you finally get it spooled would probably be too much power for a road race car to handle in a corner. Also the power probably comes on pretty strong.

 

..Yeah, you could say that. I rode in a car with a 68-1 and a 1.15 a/r hotside...bridgeported. Talk about top end power!!! I nearly **** myself that night, and will NEVER, NEVER, EVER ride in Igy's car again!

 

kkk stage one. Deacent spool time 16psi 3600 rpm. Yet still great top end

 

Why would the 20B be a bad idea for road race? too heavy? Also...i saw some guy with plans to set it up with twin HKS3037S's...I wonder if that same set up on the 13B would be better than the Apexi Rx6 Single???

 

Why would a T-78 be a bad choice? People bring up lag, but who road races at 3500 RPM's. I'd think the lag would be a good thing coming out of a corner, so as not to overpower the car. I can see where lag could be a problem in an autox or a real tight course, but not for most tracks. Doesn't Gorden Monsen road race his car?

 

So...do you think the T51R KAI would also be a reasonable choice using that logic? I'm looking to get around the track as fast as possible, so if more power with turbo lag can do it better than less power without, I'd rather go for the big turbo.

 

As far as I know Gordon has done some little "tricks" to his car I believe to get his t78 to spool by 3500rpm. Such as the trick Sard exhaust he had, in which he could change how much backpressure/restriction he had. I think that helped a little.


Racedriver in this thread says his t78 doesn't spool til 4800rpm and then the tires break loose.

https://www.rx7club.com/forum/showth...oad+race+turbo

And yeah I guess gordon has done a little road course action.

https://www.rx7club.com/forum/showth...oad+race+turbo

You might be able to get a T78 to work but I seriously don't think you want a T88 or T51 because the turbo won't be working in it's efficentcy range and you just wouldn't get a wide power band at all, which is what you want. You don't want to be just running on all motor until 5000rpm. You'll be slower than everyone out on the field. Not to mention that when you hit 4-5k the boost comes on so strong you spin the tires to oblivian. That and the fact that the a T51 set up to work in its efficentcy range would be like 25+psi, do you really want to hit 25+psi, coming out of a turn? Or even on a straight? I got that 25 psi from what I've seen people running this turbo at, around 28psi somewhere around there.

Here's the boost pattern copied from rotaryextreme's site for a T51KAI I am not sure if this is on a ported motor or not.

Boost Pattern

RPM 1000 2000 3000 4000 5000 6000 7000 8000

Boost vacuum 0 psi 4 psi 9 psi 12 psi 18+ psi 18+ psi 18+ psi


Why spend 1k extra on power that you'll never use when a better setup is available?

 

IMO it's not worth using a 20B for a road course because it throws the car off a little, in a normal autocross situation 400rwhp I think is plenty. You again would be spending 25k for horsepower that you'd never use on a road course.

By road course I am talking about a course with alot of turns...

 

well, you don't learn nothing with near 3000 posts ;P

Thanks a bunch for the insight!

 

I do have one more question acutally though...does the twin turbo parallel set up offer less turbo lag than a single...to me, it would seem that if it isn't sequintial, it kind of defeats the purpose of twin...does anyone know what are some good points of having parallel twin vs large single ?

 

Sorry I took that the wrong way. Everythings cool.






I am just a little stressed because someone decided to mess with my bankroll.

 

ummmm....that was actually a serious post black99 ^.^

I am truly grateful that there are people like you who I can turn to for advice and help, sorry If you took me wrong.

 

Also, you might wanna look at the new thread I created...so far no one has replied to it, so i assume no one knows much about advanced twin turbo set ups, perhaps you can help get it started

 

In Japan the majority of the track cars use TdO4R, and have around 450ps. But I have seen well tuned tdo4s that have 500++

 

well a parallel twin setup, i would think it would be fine... they would spool up quicker than one big single (T51 KAI or T78)...dunno about power though, but i'm sure a pair of gt3037s would provide enough power. you should check out this thread:
https://www.rx7club.com/forum/showth...ket+twin+turbo

 

T04R

 

fluxen, on this message board road races his car alot, and is running an XS tunned TO4e with a PFC. His car seams to run very well for road race-

 

For the street, I don't think anything could compare with the T04E, Apexi RX6, or the BNR twins running sequential. All will get you about the same hp figures of 380-400 rwhp at 15 psi which is plenty of oomph for the street. Also the M2 twins (although expensive at $3K) seem to be a compromise to the laggy singles. Running the stock twins parallel or non-sequential would provide more confidence out of turns since there is no blast of power at transition which could send your car out of control with a heavily modded FD - but there is some lag. Full boost is usually around 3500-3800 rpms with non-seq. I would imagine the ultimate steet car would be one running sequential BNR or M2 twins. Full boost by 2800 rpms with the M2 and probably 3300-3500 with the BNRs and excellent top-end with both.

 

I've got a T04S and just had it up at Summit Point about two weeks ago. I only ran at 11 psi and it did great. Any bigger might have started to suck lag-wise. The power comes on pretty fast but not so fast that you can't balance it. Even at 11 psi, it makes more power than I have tires, so full boost was only used on the straight sections.

I think that the Apex RX6 or the T04E would also be good road course turbos.

Brian

 

Way to go Jerky...you brought up an old thread