Hey everyone I want to see what everyone thinks of these turbos I want to setup my car for touge track and everyday used so I'm not sure witch one is the best for me bcuz I'm looking for a turbo that has small lag and makes good power and is not to much of a pain to deal with , well I hope I can get some good feed back and I'm doing all the fuel upgrades too with the turbo .

 

Did you research the turbos yourself? The 99 spec turbos are pretty limited. You pretty much shouldn't put more boost through them then the stock levels dude.

The "is not to much of a pain to deal with" made me lolz.

 

ya sorry I'm posting from my dumb phone at the airport , but ya I have done a bit of research and I want to see what everyone thinks of them bcuz the 2 of them sound good but are they good for what I'm looking for? bcuz I dont care if I can make 450hp I care more of making HP that I can used for what I'm doing.

 

wrong forum mister man

 

If your going to spend that much money for either, the 99s would be a waste of money compared to the bnrs, bnrs sequential is a nice upgrade, but still pain in the *** Haha

 

The BNR's produce more overall hp. The 99spec's produce about 50ftlbs more torque on the primary turbo than the BNR's. Both have been proven reliable on the road course. Both have had issues on the road course. 6 of 1 and a half dozen of the other.

 

Indeed... nothing spools and makes torque like the '99's. Sequential turbos are somewhat top-end limited on HP anyway... and all twin turbos (all turbos really) will need replacement after heavy track use.

 

The BNR's are cheaper, and can be repaired. Don't think anyone repairs the OEM turbos that I know of.

The BNR's can run much higher boost. Problem is the support system (solenoids, etc) isn't very reliable over 10psi. There is a solution to the solenoid situation with using better ones.

The achilles heel of the sequential system is all the vac hoses, chambers, solenoids, actuators and check valves. The OEM parts were never designed over 10 psi, and the sequential system is notoriously difficult to understand and fix. It's also hard to get to crammed mostly under the UIM. This is why most people go single turbo.

I'm hoping with the new solenoid setup I'll be able to eliminate the OEM problems of complicated vac hose setups and crappy solenoid problems. Check valves can be upgraded as well to viton.

We'll see what happens, can't hurt trying

 

What is it about the 99+ turbos that make them produce so much more torque on the primary turbo?

 

I can see how the 99s primary turbo or stock primary turbos can make more torque at a given lower rpm compared to bnrs but not overall max torque..

 

Adam- I think the main thing is the abraidable seals.

Pete- Can't wait to see the 2:08 video. Great example of the 99twins being used on track and working very well... along with a great driver.

And BTW Pete, what's your top speed on the back straight at VIR... 155-160ish? Geeeeez, That's plenty fast enough for top end

 

I'm hitting 160 on the back straight and 155 on the front at VIR. My theory on '99's vs other upgrades (that are typically "larger", aimed at higher peak power) is that the "small" size is a better match for the rest of the system. Basically, most sequential systems are limited to maybe 385 hp @ 15 psi anyway due to the flow through the manifold. That being the case, you're better just going smaller and getting better spool and torque for similar limited top end power. Of course your results may vary with non-sequential operation, porting, or boost levels above 15 psi... which I wouldn't run on the track with any twin turbo system due to heat. At 12-13 psi, the '99's are hard to beat, and you can run 15 psi on the street, which again is about as high as I'd go on pump gas. I've been running '99's since '03 or so.

FWIW, I've been running the same factory sequential turbo control system for probably 8-9 years without repairing anything. I have the saxyman upgrade solonoids in a drawer, but until something fails, it's hard to "fix" it. One thing I DO have is a pressure regulator plumbed in after the pressure tank that ensures the 'noids never see more than 10 psi.

Anyway, that's my experience. I recognize that plenty of people have destroyed '99's and other TT's on track in much less time.

 

What he said ^

 

Ptrhahn, what type of pressure reg did you use on the outlet of the presure tank? Sounds interesting..?

 

PFS put it on my car years ago... I believe it was called "SpeedAir"... if you search for posts by me, there may be a few threads with more info from me on it, including a P/N, but I've forgotten it's been so long, and my car isn't at the house currently to check.

EDIT: This looks like the thread, but I never posted a part number, or it was in another thread that got removed. When I get the car back, I'll try to remember to post some info:

https://www.rx7club.com/showthread.p...gulator&page=3

 

I noticed the opposite when I went from the 93-95 turbos to the 99s. The spool up felt the same but my butt dyno noticed the torque had dropped most noticeably in the lower boost pressures. Up top they felt stronger abover 10psi though. My original turbos had 50K miles on them FWIW. I no longer have the link, but there was an Austrailian website that had some articles on it when the 99 model was released and two had mentioned how bottom-end torque was reduced. They even had a dyno spread that compared the old turbos to the newer ones.

 

I have dyno's of both the 99spec and the stage 3 BNR's both in a sequential configuration from the same dyno. I'll see if I can find the dyno's when I get off work. I also have a M2 sequential twins graph as well as various 93-95 twins in various configurations.

 

The M2 Twins were GT25R's. Interestingly, the company that made them in Australia has since changed the kit to GT2860 (GT28R's). It's not a cheap upgrade.

 

Would be great data for us to see if you can find and post.

 

honestly, this is just my opinion, but if you plan to spend enough for BNR stage3s it is best to just go single turbo

 

We have access to both the 92-94 "early turbos" and the later model Series 8 turbos here in Australia. I have 2 identical FDs, with a set of each fitted in the shop. I do notice more lag in the older design turbos, before they come onto boost.

I think I currently have 7 sets of Series 8 turbochargers (the ones with the abradable resin in the compressor housings) and 5 sets of the older style turbos, sitting on the rack. They are much of a muchness, apart from spool time being reduced in the newer style.

My Dad's car has some weird ones- it has a set of sequential Knight Sport turbochargers. They have a polished alloy finish on the compressor housings, and "KNIGHTSPORT" cast around the compressor housings in raised letters. We dont know much about them, but he pulled them apart and balanced/blueprinted them, and that car absolutely rockets. I've been in a 400hp FD before, and his car is much quicker. Its smoking clutches and spinning wheels in 4th gear. Granted yeah, he did spend a lot of time rebuilding the motor, but I think a lot of it is due to the knightsports turbos he's using.

 

Sorry Gents, I've been away from my computer for a few days and just got back. When I get back to my personal computer tonight or tomorrow, I'll see if I can find them.

BTW, look forward to running TT with you next year Julian.

 

Hey I need to get back out there; its been two years now and car as only gone 30 miles in last year.

 

Is the spool really that much slower than the stock/99 twins? Seems to be varying opinions between this and other threads.

What about the Knightsports twins, anyone have those? Not much information, they seem to spool fast, but are prone to failure, is that accurate?

 

In regards to your first question, it depends. Everything is relative of course. If you have a street car or are just wanting to have fun on track or at the local AutoX(and you currently don't have turbo issues), I think the 93-95's will be more than sufficient and won't really be able to tell that much of a difference. If you are competing in a class where you need every last bit of usable power/torque(and things are quantified by time or postion), the 99's help a good bit I think. A couple of examples would be classes that are hp to weight, but torque is unlimited as it is not restricted. This is where the 13b-rew can use some help.


No experience with the Knightsports. I remember them from several years ago, and remember a few members having them, but not much else. Seems like Carol(Imstillonjava) had a set maybe? Not sure if she ever had them installed though.

One other element that really hasn't been brought up in this discussion(and is a big one IMO) is we all know Bryan@BNR. We know his turbo's and how well they work. We know he does good work and if you have an issue with his turbo's, you can give him a call or shoot him an email and have great technical/customer support. That's worth alot.