Anyone have any experience with M2's ball bearing turbo upgrade?

My stock turbos are shot to hell, and I can't rebuild them because of the huge cracks in the manifold. I'll need brand new stock turbos, which run between $3000 and $3500.

For that kind of change I could install the M2 BB turbos for $2995. I'm not interested in running more than 10 psi. I AM interested in very fast spool-up time, reliability, and longevity of the new ball bearing turbos. My motor has 92,000 miles. I have very minor mods--K&N, RB duct, Bonez hi-flow cat, Trust Sport catback, 10.5 psi boost control pill, stock ECU.

I posted to the big Rx7 list, but only received a few constructive replies. I did get hammered for considering ball-bearing turbos WITHOUT being interested in running 400-rear-wheel hp, and 18 lbs of boost. As I replied to them, dyno numbers don't mean anything to me. I'm about reliable, consistent, and practical power and how you can apply that power for turning quick laptimes on a high speed road racing circuit.

Thanks in advance for your posts.

Merry Christmas and God Bless!

 

One of the guys here bought them. There are a few threads about em. Do a search for ball bearing turbo and you should be able to find those threads. They consist of the feel and also a dyno run and some good information regarding M2 and a possible modification to them.

 

Ya, I think a guy with the name "capt bill" or something bought them and is having his car dynotuned with them on. Do a search. I have heard very good things about these turbos.

 

May you have a Christmas filled with forced induction!!! I'm about to go force a few egg nogs down, but figured I'd say hello & chime in before I go. We've talked a while back about suspension mods - off the big list.

Someone on the big list mentioned the 99+ turbos, and I thought I'd add my $.02 about them since that's what I have. IIRC, you want to stay around stock boost levels, right... and are looking to get faster spool up... correct me if I'm wrong. These were two of my major considerations for purchasing these units from Japan when my stock turbos "retired." They both spool up faster and more efficiently produce the desired level of boost (compared to the stock twins) due to the new shaped blades and the abradable seals in the compressor housings. They are really fun to drive around in and completely kick *** for autocrossing - haven't had them on the track yet so I can't speak to that, but again due to their lower temperature output I think they are a plus at reasonably modest boost levels.

Frankly, I think the M2 ball bearing twins are for people who still want twins but want to make big power. What I really think it comes down to is what your goals are for the car. I think I know you pretty well in this dept. after a couple years of posts, and I think you'd be happiest rebuilding your stock twins and spending the money on a few extra track weekends this year. The only raeson I went with the 99's is that I wanted NEW turbos, not rebuilt, and they JDM turbos were only a couple of bucks more. I had nothing to lose so the slight gain was worth it.

Scott
(celebrating the holidays in the hoosier state)

p.s. Santa got me a day at Evolution Autocross School

 

Duh... you said your manifold was cracked and your old turbos were shot. My revised suggestion would then be pick up a used set that needs rebuilding and send them out to a competent shop. ****, I would have given you mine if I still had them, but they were over 100k miles when I chucked them. I figured nobody would want them anyway.

good luck.

p.s.s. Corksport or Mazda Comp should be able to get new JDM turbos for about 3 grand. Don't know where the yen is vs. when I got mine earlier this year. But, that's still cheaper than all the mods you will need to do to hook up the M2 turbos - you'll need at least a new intake setup which noone makes cold air ducting for that I know of... and boost ontroil is another issue...

 

I spoke to mazdacomp (when I purchased my new set of stock twins) and inquired about the 99's but unfortunately they did have any in stock. They have three on order from japan and should arrive in feb some time. I do not know if they are "spoken for" already. Other distributors I spoke to also order their 99's from mazdacomp. Wish I could have waited until then but its my daily driver and have to be back on the road by Jan, 2.

Happy Holidays,
André

 

Yes, Scott, you know me better than anyone else who's posted a reply! BTW where have we met "road racing"...perhaps MADS '99 @Summit Point? That was the last time I attended a big Rx7 "racing" event.

Anyhow, I like your idea of going with NEW '99 J spec FD turbos. I want to know more about how to set those up. My mods are modest. I'm using a Rotary Performance boost control pill set for 10.5 psi with RP's high-flow cat, Trust catback, RB duct, and K&N filter (with stock airbox), and stock ECU.

How about a few details on what I'll need to make the '99 turbos work with my setup?

Andre, I'll need to place my order for those J spec '99 FD turbos with Mazda Comp first thing tomorrow morning!

Thanks for the ideas!

Merry Christmas, and best of luck in the coming year!

P.S. to Scott. If you're in Indy, email me, and we could meet to talk about turbo stuff...perhaps at an indoor go-kart track, like Racers http://www.racerskarting.com/ ?

 

Manny - I'll post a response to the forum since others may be curious as to how to make the 99's work.

I was at MADS fall 99, but I don't remember meeting you or seeing your VR. Met a bunch of cool people that weekend... I'll be at the next MADS though.

When I first put on the JDM turbos, I had the same mods you do (except a stock main cat). I did however put in a PMS, but I have kept it on the low setting and used it only for boost control, not for adding fuel. AFAIK, it is not altering the fuel maps at this setting, but I could be wrong. I think that if you intend to keep the stock boost, you will probably NOT need an ECU upgrade. As for boost control, you will have to decide on a strategy. The new JDM turbos do not come with pills in the lines like the stock turbos do. Frankly, I'm not sure how you could still use pills to control the boost, but it sounds possible. You probably will have to tinker with different pills to get it right, but maybe not. Oh, and I am pretty sure you will need the Efini Y-pipe. You don't currently have this right? Other than that it is a direct replacement, so you can stick to your stock airbox with the RB duct. I used that setup for awhile before I gave them to another lister.

Again, my main reason for going with the 99+ turbos was that I wanted NEW turbos, not rebuilds. Maybe that was just a little ****, but I was willing to spend the money to do it. Hopefully I won't grenade my motor anytime soon and spew apex seal chunks through the blades. That's a risk as my motor is near 80,000 miles.

All that being said, in the words of Jim Carrey, I like them A-LOT. I can't back this up with solid numbers, but they do spool really fast. When you are cornering under acceleration, it is easy to control the acceleration because the boost builds so fast - allowing you to control the rear slip angle with very slight throttle adjustments. Since they also run cooler, theoretically they should make slightly more power at the same level of boost as the stock turbos since the outlet temps will be lower (giving you a denser charge). You just need to decide if this worth 2 grand more than getting some rebuilds. I'm set up to run upwards of 13 psi these days, and I think it was worth it.


Scott

p.s. Manny - I'm only in IN for one more day, and I'm up in Ft. Wayne at my girlfriends family house. Would have LOVED to go karting though! We have a indoor place near Dulles airport in DC that uses JB Karts with timing to the 000th of a second.... its sweet. I try to get out there as often as possible to get some seat time.

 

Scott,

Great information.

Hmmm, I really don't want to tinker too much with the boost control. I've got it set up nicely with the stock twins, 10.5 psi wastegate boost control pills, and stock ECU. I also don't want to fool with buying Efini Y-pipes. As you might have guessed, I'm a "set-it-and-forget-it" Ronco type of Rx7 enthusiast

Perhaps Falcon's idea of staying with brand new stock twins from Mazda Comp will be "sure-thing" for me

I will be at MADS in 2002. The Fall MADS is when the full VIR course course is run, right?

 

It may be worth investigating whether your current pills will work - they might be just fine after all As for the Y pipe, come on Manny! What's an extra 240 bucks when you are throwing down a few grand for turbos already I don't think it would take more than 15 minutes to do once the turbos are out. In any case, the old Y-pipe MIGHT work.

Not sure yet if MADS fall 02 will use the full course. The last meeting I went to was just before MADS fall 01 (I was going to go before falling victim to raceaflais), and I don't think it was lined up at that point.

Later.
Scott