Which is the Best Single Turbo Upgrade for the FD3S?
 

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 shit 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.



:D


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:)

I went with the RX6 because I was afraid of lag, so I was looking for the most lag free turbo on the market. What I got was a turbo with only a little bit of lag more than stock but a lot more high end. However, if I could do it over again I would have gotten a bigger turbo like a T04r or a t04s. Many road racers in japan use the T78 such as the C-west FD. other such as pan speed use a T04S. On the road course you are always in between 5000-8000rpms anyways so you really don't need to fear the lag. If you want to drag race, get the XS t04s kit, if you want to road race you may want to think about putting together your own kit. Lag is overrated especially in road racing. As long as the boost comes in with a smooth delivery and doesn't just kick in really hard and sudden at a certain rpm it is ok

The yellow One Lap car was very successful with a T78.

I like single or parallel for road racing because it gets rid of the transition. With the sequential setup, you have to use less throttle coming out of corners sometimes so you don't lose traction and spin when the second turbo hits (yuk).

In my opinion, the only reasons to use bigger twins is to stay sequential or pass the visual SMOG inspection. And I don't think sequential is good for road racing. The SMOG thing is a good reason, but if you don't face that challenge, a single is the best way to go.

I have the RX6 and it works nicely. It takes a good driver to make use of all the power it provides. It it a much faster car than I can really make use of, but I enjoy wrenching on it, too, so I got the single turbo. It is nice to be free of the transition. I think the fact that it is a "dry" turbo might help keep the coolant temps down, too. It doesn't run any hotter at 370 RWHP with the single than it did at 330 RWHP with the twins. And the power is more consistent -- it stays strong longer and it does the same thing every time you hit the gas (the control system never gets confused or sluggish). I did have to replace the wastegate, though, after it started sticking on track days. Even with the sticking wastegate, though, it was still more consistent than the sequential system.

I wouldn't get a HUGE turbo like a T51Kai or the T88, though. They might be too peaky.

-Max

How come no one mentioned the gt 35/40? Is this not the turbo to go with? Is the T04S ball bearing?

I am debating between the XST04S and the GT35/40. My car will be mostly 1/4 mile racing, not road racing so these two are the top two on my list. T78 requires too much cusotm fitting I have heard but I like the size of it.

I like the gt 35/40 setup, nocab posted a pic a while ago that showed the boost gauge and tach boosting 15 psi @ 3500 rpm. The thing has great top end, ihor got 430 rwhp @ 15 psi, but most people think the sweet spot is around 19-20 psi....and if you were running that much boost you would spool even faster, because the wastegate is venting air later.

kyle

The One Lap car (Rick Potter) has a 60-1 p-trim...

Brian,

The T-04s is NOT ball bearing. I've heard comparisons between the two(flow charts) and from previous discussions, the 35/40 is essentially a t-04S ball bearing.

anything around a T04R. After that it depends on if you can drive and if you know how or where to tune your car... NUFF SAID

heheh, who dug this one up? :D

...was nocab running a GT35/40 vs the blown Saleen in that video???

If you want a car not for 1/4 and more for twisties I would consider following the route Max took.. The Rx6 is a great turbo and though you won't get the huge HP bragging rights....hey that's more for 1/4 racing anyways.

I ran a XS T04S kit daily driven and had no problems. There was very little lag though at times i wish i had quicker spoolup.

If you can afford it you can try to go with a BB turbo...As far as kits I know for a fact the HKS does not sell any kits for the FD that utilize their GT turbos.

In Japan they do run HKS GT turbos but those are custom kits. And hell if you have the money you could always try to build one. GT3240 is almost like a bb TO4R and the GT3037 is awsome also.

I almost forgot that a T04E would be a great turbo for your needs...out that on to a well built motor and you have a great responsive car.

Chris

Has now or had during the competition? I thought he ran a T78 for at least one of the One Laps.

-Max

Hi Guys,

I was pretty down today to find out the following from my local mechanic.

Even though i have read people reaching >330bhp on stock twins, he has said there is no way mine could achieve that.

I have the standard mods, FMI, CB, Power FC, it makes a modest 270hp, last time i was in he saif the only restriction now was fuel.

So i took it in and requested fuel pump upgrade and injectors, he now says there is no point and that if want more the 270 i need to go single....

So pretty annoyed at that im looking for a turbo to suit my needs, or a new mechanic, but there is none where i live.

What would be a good turbo for 400+hp and quick spooling? more importantly a good kit that is an easy install.

Thanks guys

Hey man, first off, welcome to the forums!

Secondly, you just responded to a thread that's over 10 years old. There will be lots of answers to your questions in the Single Turbo Forums and the 3rd Gen Forums.

Good luck to you!

Haha thanks.

I will post it some where else, what do you think of the mechanics comment i was told today?

I think your mechanic might not be the best choice for working on a rotary, or that there is more to the story of your car.


And yeah... Holy thread bump!

I hit 270 recently with stock fuel, CB, Intake, Downpipe, And high flow cat midpipe. My tuner said I could get more with a fuel upgrade and a midpipe. Are you still running stock cat? Also look into BNR stage three turbos. They are upgraded twin turbos and people are getting 400+ out of them.

Staying sequential, BNR Stage 3's can get you close to 400whp.

If you have no attachment to the sequentials (I do have a strange attachment to them) then go single. The next thing to do is pick a turbo that will not be too big or too small for your goals. I always laugh when you see someone with a t88 and then they say "I'm running 8 lbs of boost and it spools at 5000 rpm". Good sign they didn't need that size of a turbo.

I have pretty much all your standard mods, Front mount intercooler, Greddy intake elbow, Exhaust system (No CAT) and Power FC.

Originally he said the only restriction for me was fuel, so that's when i decided fuel pump and injectors where the next thing on the cards for me. but now he has changed his tune.

It ruined my day when i dropped it off

I have looked into BNR Stage 3's, unfortunately the owner before me totally gutted the sequential setup so single would make more sense, well to me it sounds like the preferred step, however i don't believe any turbo change is required at the moment.

Ok, more to the story, i phoned another garage in the city and discussed my circumstances, first thing he said is the garage i go to uses a dynamics dyno bed which apparently reads low results, as much -12% then other dyno beds.

Any how he also said that even with fuel pump and injectors i wouldnt see a improvement worth while, so im going to go single and attempt the install myself.

I am deciding between the T04Z or the GT35R, can you guys list the pro's and con's between them?..

Very different turbos-

T04Z is a well sized turbo for the rotary for a broad powerband *at the track*. Many Japanese time attack cars use this turbo with street port to semi-peripheral port set ups. It will feel a little lazy on the street.

GT35R is about the smallest single turbo you would bother replacing the stock twins with. Very good powerband for the street, but will require higher boost levels to make more power than the stock turbos power potential. Different specs (T3/T4 exhaust housings) are available for this turbo and will effect its performance greatly on a rotary.

What boost levels are you planning on running? Pump gas or race gas? Use on the street or track?

If I were to do it again. I would go with stock ports with something a just a tad smaller than the gt35r.

Not to continue on an old thread that should be in the single turbo section...but I have to ask isn't the T04e smaller than a GT35 and people have had good success with? Should be able to produce high 3xx whp without too much trouble right?

The T04E compressor cover is smaller than GT35R compressor cover.

The biggest GT3582R has 56mm/82mm compressor wheel and 68mm exhaust wheel.

The biggest T04E 60rim has 58mm/75mm compressor wheel and 74mm (P trim) exhaust wheel.

So its up to you which you call larger.

The main thing is the old T04 turbos are more efficient at lower pressure ratios and the newer GT line more efficient at higher pressure ratios.

The old T04E or T04B 60 trim turbos are still a great turbo for 400RWHP at 14psi boost, but the newer GT line will make more power at higher boost levels.

Garrett GT35R has a 61.4mm compressor inducer..... it also will definitely make more power than stock twins for a given boost level. I think you're selling it a little short :)