vilfredo

Hello all, I have a 94 touring with all the normal bolt-ons and a street-ported motor; as such, I'm now contemplating what to do next. As an alternative to a 'moderate' single turbo conversion (rx6, T78, etc ... 400-ish RWHP on premium), i'm considering going to the 1999-spec twins. I've heard from one source that they're good for 40 additional HP over the setup from the previous years (which would put me in the range of the above figure), and changing them out would be relatively easy, and visually easier to get past emissions. I plan to keep it on pump gas, so the higher flow and HP potential of the single at really high boost isn't a factor for me.

Although this seems good in theory, I've heard and noticed that upgraded twins can either be unreliable or equivalent in power to the stock ones. Any info (hands-on, second-hand or otherwise) on the 99 spec turbos would be appreciated (I have noticed that PFS has them listed on their site for about 4 large).

Vilfredo

maxpesce

The turbos themselves are the same - the increase in HP comes from changes to the Intake, Catalysts, and Exhaust and a remapped ecu

Coulthard Fan

BZZZZZZTTTTTTTT!!!!!!!

Wrong answer - they are similar, but different in several ways.

I know because I have them. I'l l post more later - have a meeting to go to.

Scott

QuIcKSiLvEr

The jspec turbos are actually a bit smaller aren't they?

JspecFD

iTrader: (2)

Mazda still offers 2 different types of turbos depending on which model. By '99+ turbos, most people refer to the newer/better/more powerful one thats offered in the top line models(first only on the '99 RS).

Yes, the newer/more powerful turbos are slightly smaller(50mm v. 51mm). They also have shaped fins and an abradeable compressor seal. Mazda calls them "ultra high flow turbos" Net result is that they spool faster than the old turbos while providing more hp on the top end(~15hp according to Mazda). Mazda also lists the fact that cars equipped with these turbos run slightly more boost as well.

That 40hp quote by PFS seems optimistic but no one has done a before/after dyno run that I've seen which I'd be very interested to see. Mazda's performance claims may also be a little pessismistic as well.

Coulthard Fan

This is what I was going to say too. If you REALLY want the details (and you should get them if you are spending $$$ on NEW turbos), you should read the article Yamaguchi wrote on the 99+ J-spec RX7. I can tell you that my car is more powerful as a result of the upgrade to these 99+ turbos, but I also did a downpipe at the same time so the results may be partially attributable to that mod as well. These turbos spool up really fast... I mean REALLY fast. I don't think that I am ever more than 1 second away from FULL boost, and usually it is much more like instantaneous to less than half a second. [in any gear] The biggest difference that I like is the throttle response, not the slight power increase. Admittedly, I have a light flywheel, but honestly I can spin my (street) tires in the lower gears by thinking about pressing the gas pedal. Cornering while accelerating is much more fun because you have more control over power delivery. Dare I say it... its more like having a V8.

Of course, this doesn't mean its right for everyone. If you just want big power, go single. It might even be cheaper to do that if you already have the right ECU and other required mods like an IC. Since you already have ported your motor, you would probably be happier with a bigger single - but that's just my guess.

Scott

Tim Benton

iTrader: (1)

Who else sells the 99 turbos and how much? I can't find them on the mazda comp website. I have the SR Motorsports twin upgrades but there's jsut some piece of mind in knowing your getting a new set, not a reman set.
I'll gladly sell mine at a discounted price since they haven't been on the car yet if I can get a hold of the 99 turbos.

Tim Benton

JspecFD

iTrader: (2)

MazdaComp does offer them(as well as lots of other items) even though they aren't listed on the website. I talked to a person who was investigating it and he said their price was ~$2400. If you or anyone else get them, it'd be helpful to do before/after dyno runs as a service for the rx7 community. That way, the quicker spoolup and higher hp can be analyzed(Mazda did publish a small chart but its not that helpful)

I've also heard from a couple different sources that the 99+ turbos incorporate a larger shaft. haven't solidly verified that yet, though

Red95T-Rex

TIM,
I'LL BUY YOUR TURBOS! My car is at Rotary Performance right now having the motor ported and getting race seals. I noticed some oil consumption, and oil residue on the 2nd turbo shell, so I may be a candidate for new ones. Let me see what RP and my Warrantee say. If my warrantee approves my turbo replacement, I would like to upgrade to the SR modified stock twins, or the M2 BB modified stock twins. E-mail me with a price when you get a chance, and I am gonna give RP a call tomorrow to see the status of my car. Thanks!
- Kevin (KEMRX7@aol.com)

Tim Benton

iTrader: (1)

Kevin,

I e-mailed you saturday, let me know what you think about buying the SR upgraded twins I have yet to install.

Tim Benton

Jason

iTrader: (5)

I carry them at the RX-7 Store. Although I dont have them in stock. They are not worth the $2500.

Jason
www.rx7store.net

Coulthard Fan

I think that it's really a subjective issue. Personally, it was worth that much to me - my car is more fun to drive around the city than it was before. If you are in the market for NEW turbos and don't want to go single (for whatever reason) is there a better option?


Scott

Tim Benton

iTrader: (1)

Jason,

Who do you get the 1999 spec turbos from? I was going to call mazdacomp but since I haven't had time to get a couple of events in this past year, I don't qualify for the racer discount. How long would it take for you to get a set in of the 99 spec turbos? And how can you tell the difference, number of blades and blade curvatures?

Tim Benton