I own a 1994 R2...

Jim may ask you scan the title...he has been known to do that, ha

 

No, it wasn't clear. The number of people on this forum engaging in detailed conversations like this one in the event they might buy an FD is large enough and occurs frequently enough that your statement could easily be taken at face value.

Your apparent lack of knowledge about your own car increased the believability ten-fold.

 

While I wouldn't do that for privacy's sake...if he wants to venture into the NE Regional Forum, there's quite a few pics of it...(either that, or I just stand pretty next to someone else's car a lot LOL)

Yea...I gotta agree w/ you on this one. I've seen it happen a couple of times. I try to take things one step at a time...and on that note, I'm discussing this and other issues (like the MAF, etc) because I'm having my engine and turbos pulled pretty soon, so I'm trying to sort out exactly what setup I'm going to be going with...

LMAO . As demeaning as that was lol, it made me laugh, and I can't argue with it. I picked this as my user name for a reason...

BUT...Jim, I do have a VERY valid excuse (at least it is IMO). I thought I posted it earlier...https://www.rx7club.com/showpost.php...5&postcount=46

Hey...I'm glad you're proving me wrong. This is excellent news lol.

I did a search on them, I got a thread or two about each, neither w/ any serious info. This was the best I found...

https://www.rx7club.com/showthread.p...or+garage+alex
https://www.rx7club.com/showthread.p...t+sport+turbos

They're a year and two years old, respectively. I tried checking out both the Knightsports website and Motorgarege's website, but it was in Japanese...so I didn't get very far. And I didn't find the Knightsports twins on JT's webpage...

Obviously, my first question is, are they sequential upgrades? From what I read, it seems like the Knightsports are... can you help me find further info about these or any other upgraded sequential twins from Japanese companies? Because I honestly believe that if we KNEW about such options, threads like this wouldn't exist...(and then Jim would be happy! hehe)

 

There was a thread very recently (maybe last week) - which had what looked to be a full page ad (or article, can't remember) for knight sports - If I were you, I would take that to someone who would be kind enough to translate it. I have a dyno sheet comparo (with a single set-up) lying around somewhere - I'll try and find the magazine.

As for jason's comments in that link, re: knightsports, I have to wonder if he's saying that because he doesn't stock them - at least in terms of quality. I've seen a fair few knightsports items and I have no idea what he could be referring too. They've been around a loooong time, and have made a good name for themselves for good reason (and their workshop is very full-on, in terms of equipment). He got one thing dead right though: $$$$$$$$ (not cheap). I haven't got anything to refer to at the moment, so I'll post up later. Very briefly - the garage alex items didn't look as shiny and nice as the ks ones, but they were good for pretty much the same general hp area. And they were a hell of a lot cheaper.

BNR vs 99s vs Japanese aftermarket vs single....?

well - single is the simplest set-up, can produce the most power, but can't replicate the powerband of the twins

99s are a LOT of cash. I'm actually surprised that they are so popular in the US. Abraidable seals are a win-lose upgrade.

BNRs seem to be the best bang for buck (for twins enthusiasts) - but problematic from my experience on this forum

Japanese aftermarket - expensive. But honestly, I would choose a set in a second if it was between 99 spec and these.

 

WOW !!! can't believe how far this has gone !!!!!

Simply a waste of time and money !!! unless you like to experiment......

The exhaust side of the MKIV T-turbo system seems better enginneered .....explains why some owners run boost pass 20psi without boost drop at higher rpms.

The FD twins will easily make 350-390rwh with the correct bolt-ons and proper tunning and as light as the FDs are....this is good for 11's !!!!
- How fast do you guys wanna run ??? 11.99 and below will require cage and other safety equipment. With this much power you will easily keep up with a 450-500 rwh MKIV as well.

The Infini FD twins are actually 1mm smaller then the std Fd twins.....they respond better *but* will not out flow the std twins.
At higher boost....the bottle neck is in the turbine/manifold design....simply too small to flow ~400rwh.

I had the pleasure to meet the fastest twin-turbo(OEM) MKIV @ Etownraceway....
forgot his name but seemed to be a pretty cool guy and told me he had run 11.2 @ 126mph a bit over 20psi....126mph shows the amount of power he's making in such a heavy car.
Funny part, he originally approached me to ask if I was the one with the fastest twin-turbo FD.....the he proceeds to say "me too !!! 11.2 @ 126mph in the MKIV Supra."

Just my $.02

 

I'd like to suggest a new direction for this thread: Get the twin sequential system from a 959 and install that on an FD. It seems like a better match since the 959's engine size is closer to the FD's than the Supra's is.

-Max
tongue firmly in cheek, flame suit on, running away giggling...

 

Ha ha ... very funny Max lol.
DaiOni is this the thread you were referring to? https://www.rx7club.com/showthread.p...tsports+turbos

I found it a couple minutes after I posted...so far it's the only other post I've found about them.

I gotta agree w/ you on your analysis...the only question is just HOW expensive are the japanese aftermarket twins, and what are people's experience w/ them?

 

Sweet. That's exactly why I mentioned the weight difference earlier. Who cares if we don't get the same exact HP #'s, we don't need em to get that far/fast!

 

Yeah, but they're JDM turbos. That's got to be worth something, right?!?

People see the 280ps rating of the Japanese FD and assume that the "upgraded" turbos are responsible. It doesn't help that JT Imports actually states that on their new/used JDM parts page. ("This the the same turbo used in the 99-current FD's. Stock it comes with 280hp...") They don't understand that relaxed emissions are primarily responsible for the power difference. Getting rid of the U.S. pre-cat and bumping boost up a little would produce roughly the same results.

 

You can't compare peak power to weight ratios and assume that they mean that one car is faster than another.

First, peak numbers are exactly that; the single point out of the entire power curve where the number was highest. The rest of the power curve is equally important, if not more so. More area under the curve is what you're looking for. More average power over the usable rpm range.

An engine that produces more average power will accelerate faster for a longer period of time than one which produces a peaky spike of power (read: 2-rotor rotary engine and any other pathetically undersized engine with a turbocharger). The spikey engine will feel faster, because you're delivering all your power over a much shorter rpm range, but it will not necessarily be faster, even if it has a somewhat higher peak output than the other engine.

Second, power to weight ratios don't take gearing into account. A car with a broader, more powerful curve can take advantage of taller gearing (lower numerically) and build wheel speed. Wheel speed moves the car down the road. It's a simple fact; the car turning its tires more often wins, with traction, and assuming relatively equivalent tire heights. That's why cars like the McLaren and the MKIV Supra with close-ratio 6-speeds and very tall gearing are such incredible highway monsters.

The 4.10s in the rear of the FD really have one purpose... multiplying the available low end torque enough to get the car rolling. No other car that I know of has a 14.xx:1 final drive in first gear. No other car needs it, to be honest. The fringe benefit is that it also means more torque multiplication in every gear, and the FD can use the help.

The point is that you cannot assume, especially if the numbers are relatively close, that power to weight ratios tell the entire story of which car is faster. The stock MKIV Supra turbo was 11.1:1 (320 horsepower, 3550 lbs.) while the stock FD was 11.0:1 (255 horsepower, 2800 lbs.), yet we all know (or should by now) that the Supra was unarguably quicker and faster.

 

Getting back on topic, it's worth mentioning that most of the Japanese vendors that offered twin parallel turbo upgrade kits in the past no longer do so, as far as I know. For example, FEED used to have a twin kit that used TD05 turbos, I believe, which they no longer offer. A single is simpler, more cost effectively, and will usually produce more overall power. You'll notice if you look through a recent Japanese magazine like Hyper Rev or Cool Style that almost all of the vendor cars have single turbos if they don't have stock twins.

I had a picture somewhere of the FEED kit installed, but couldn't find it. There are people building twin parallel turbo manifolds still (one in a very recent thread, in fact), and Kevin Wyum has a twin configuration in his car, with T04/T3 hybrids (shown below), so they're out there. The best option for someone wanting to go a step farther than the BNR twins would be to find someone else who has already done the work of fitting and fabricating their own twin turbo kit.

 

I don't own an FD, but I like reading about the twin setups, the tweaks and what you do with them..
Not gonna get to involved with this, but I will add my .02 to this after reading all 6 pages of it and seeing alot of twin "tech" in Japan last year..

If you totally ignore port timing,overlap and ve. but yeah the supra motor is more thermally efficient..

From Hyperrev mag
There were 3 levels of power ouput for the Japanese models as well 255, 265 and 280, so its not really about lower emmisions standards as both countries had the FD rated at the same power level in the earlier years. Although in Japan, 280 was the maximum they could quote regardless of what the power actually was on an oem car.

You are right though about it not just being the turbo, the extra power for the 280 hp type Rz was also due to a better exhaust system, the best translation I can get from my Japanese mags is that Mazda thought it would be better to find more efficiency in parts that do not add more stress to the car rather than simply, increasing the boost level beyond a safe level or by pushing the limits of the tuning of the ecu. To get full of effect of the rz rating and parts, you would need the rest of what made the rz different as well.. There is no difference between any of the FD turbos apparently on the turbine side...

I don't know who is making the cash off selling the twins even the 99's, when I was there, one shop asked me if I wanted a couple of sets of them to play with, they were piled up in a corner like old boots...Now I kick myself for not shipping them back.. Its not so much people changing them for singles, but the shops dissassembling wrecked cars and cars that won't pass safety.
Alot of circuit cars in the options/hyper rev are running stock twins and quoting 375-450 as power ouput, some people even graft them into FC's..
I guess a cheaper way to upgrade on a FC rather than manifold, wg, turbo etc etc, when you can get fd twins for basically free, there...But supra twins on a FD, it if meant any welding, I think I would opt for a big single first.... But as one guy there put it , intercooling, intercooling, intercooling, then turbo upgrade..
For other twin kits, most are shop built up systems there are some package systems still availiable, HKS,apexi, and greddy at one point all made them, saw some new in boxes, sawsome used over there.. The ball bearing Gt series seems to be very popular for the built up shop systems, Reckless, KKM ,axia all offer twin kits based on apexi rx6 or hks gt turbos..
Lots of places have upgraded stock twins there with completly differnt comp housings and comp wheels, we never see some of it, because they don't consider anything outside of Japan as a worthwhile market..
Max