capt. bill1

OK, heres the lastest. Took the car to the shop to see if we could find the top end problem and why the engine is not making the HP it should. Checked the fuel pressure, 45 - 50 lbs fuel pressure to red line. Pump seems OK, regulator seems OK. So far so good. Injectors maybe? Getting some used ones and having RC rework them. While it was in the shop I asked them for the heck of it to check the J&S knock sensor. As even at max sensitivity it never seems to show any retarding. Guess what? Put the sensor on an ocilloscope, works fine. Hook it to the box, nothing! Box is bad. Bypass box, car runs stronger! Idles better, pulls better. Does not seem to have stumble at 6000 rpm and seems to run about 10 degs. cooler. My guess, box was retarding timing all the time. Ok, send it back and get working box. All in all, simple fix, good news. Now the bad news. While on the dyno noticed oil leak around turbos. OK, no big deal, inlet line, outlet line. WRONG! Turbo seals! God damn it! Now I have to have M2 send me another set. Fun, fun, fun! And I still need to find out why I only saw 12.4 - 12.6 A/F ratio at full throttle. Could the ECU have been seeing the retarding of the J&S and for some reason cut back on the fuel and act like a rev. limiter?

petrosc

Damn! Sorry to hear that. Well, we can still get that dyno plot.


Petros

Jetlag

No, as you know the J&S and the ecu are two separate units. The ecu knows when the timing retarded, but it does not pull back any fuel. The RX7 is equip with ignition type rev limiter.

maxcooper

The ECU does not know when and how much the J&S retards the ignition. The J&S is between the ECU and the ignition components down the line, and thus there is no way for the ECU to know what the J&S is doing.

The ECU will know when the engine gets hot (for instance because the J&S is retarding the ignition), but it won't know what the cause is.

-Max

capt. bill1

maxcooper, Jetlag, thanks, that's what I thought.

petrosc, I'm thinking about doing another dyno run to get a new base line now that I know the J&S was messing up the timing.

capt. bill1

New, potenially good, news. M2 is now saying that because these are ball bearing turbos they do not need as much oil going to them as the stock ones get. So the first of the week they are going to tell me what they want me to do to restrict the flow. Hope they are right on this.

newRX7fan

iTrader: (1)

Capt Bill-

Do you mean the turbos were leaking oil at the bearings? How'd you see that externally? And M2 says that was caused by too much oil flow to the turbos?

I'm very curious because I mostly likely will be buying their turbos, and I want to find out all the 'gotchas' first

BTW, a similar thing happened to me with my J&S. The connector came out, and it made the engine run so hot (running with trailing plugs only) the exhaust manifold ended up warping and I had to replace it.

capt. bill1

newRX7fan, my first clue was when I would park in the grass I would smell oil. But when I parked on my driveway I did not really see any oil under the car. Then after my dyno runs there was a puddle of oil under the car and when I looked under it I could see oil on the rear turbo. But I just though it was an oil line. The oil only comes out under pressure when the car is running thats way I did not see any oil under the car after it was parked. Like I said, M2 is telling me that these turbos do not need as much oil going to them as the stock ones do. Now I can see how we can restrict the volume of oil going to the turbos but it would be harder to lower the pressure. So I hope they are right that it is just the volume and not the pressure that is causing the leak.

Yeah, can't believe how much better the car runs now that I have bypassed the J&S box. After talking to J&S, my friend who installed it and Arie at RX7.com where I bought the box I am going to double check the wiring one more time and then send it back to J&S. I tried to explain to them that this was far from the first box my friends shop had installed and that we had described the problem to Arie and he had said to call them. But they still questioned the wiring and if we had tested it correctly. I am afraid I was a bit short with them on the phone but you know how it is when you buy something and install it, or worse yet, pay to have it installed, and then have to take it out, sent it back and reinstall it again.

I will post to the forum how things progress and the results of any new dyno runs I make.

SleepR1

Capt Bill1,

I'd like to know more about your experience with your M2 BB turbos. My stock turbos are shot (blowing oil into the intake and white smoking out of the tailpipe under hard acceleration); and will need to replace the turbos before my next racing event (Mar 2002).

I cannot rebuild my current turbos because of the huge cracks in the manifold. New stock units from Mazda Comp are $2500 (according to "Falcon"). The M2 BB turbos are $2995. I was thinking of going BB turbos as replacements for the stockers. I plan to stay with 10 psi and use the stock ECU (stock boost and fuel maps).

Any guidance or advice you have would be received with gratitude!

Merry Christmas and best of luck in the coming year!

Want2race

I have some bad news for you!
Im on my 3rd set of highflow BBtwins.. The RX-7 setup is too hot so the seals constantly fail! The set on my car now are leaking BADLY! ( 1quart every 200miles) and im going single very soon!

Just send em back and get a set of stock twins... HIGHFLOWS are bad news!

~jon

SleepR1

It sounds like that M2's ball bearing turbos were a good idea, but aren't working out for the FD Rx7 application.

"Falcon" has also posted a note on how unreliable the M2 BB turbos are due to their susceptibility of contamination screwing up the bearings.

I think I'll go with brand new stock twins from Mazda Competition Parts to replace my tired 92,000-mile turbos!

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

Falcon

Retraction.......

For the record I did not post a dissenting opinion on "M2's Ball Bearing Turbo's". I believe M2 has quality products which I have purchased and will again. Having dealt with high performance products for many years there is usually a downside to burning the candle at both ends. You have to make your own choice as to what you well accept in terms of issues with fit, form, and function. I was recently in the market for turbo's and weighed my options. The generic ball bearing setup gives faster spool rates which is very attractive, but for "me" require more care and feeding then stock units (oil contamination as a daily driver being one of those issues). In most application the production automotive industry has chosen sleeve type bearings because they are more forgiving for daily use. That is not to say for those wanting higher horsepower (while retaining sequential operation) that ball bearing turbo's are a bad decision. For my application, the stock set fit my comfort zone, though I would have preferred the 99+ series set if they were available. As with all high performance parts you have to weigh the options, understanding your requirements, and make the best descision that fits your needs.

Take Care and happy Holidays,
André

SleepR1

Falcon is right. He did not post to the forum directly. I apologize. I also apologize for calling the ball bearing turbos, M2's ball bearing turbos, in my last post that I attributed to Falcon. What I meant was ball bearing turbos in general, not specifically M2's BB turbos.

I do whole heartedly agree with Falcon's last post, which is why I'm no longer pursuing ball bearing twin turbos as replacements for aging stock twin turbos.

Best of luck to all in the coming new year!

Falcon

SleepR1 you are a good man with "honor and integrity" and thank you!

Take care,
André

artowar2

Capt. Bill any news on your tuning efforts? Thanks.

JoeD

damn...this post is a year old!

id love to hear what been goin on lately, capt.

dznutzuk

iTrader: (1)

I have an upgrade kit that utilizes new Garrett cartridges, all you have to give is your housings to be reshaped. These turbos last and have lasted a while now at 18psi putting down 407hp. The price is $2,700 although you have to figure out about customs from Europe. Alternately you can call Jeff at Pettit Racing and ask about Spyro's upgrade.

artguy

latest news is this....both captn bill and I are still waiting for a restrictor pill that will keep oil from blowing by the seals and burning off...it is minor and while m2 claims that the oil going thru and burning will not damage the turbos I wonder how much residue might build up....supposedly the pills will come this week. no luck as of tuesday..maybe tomorrow.

last I heard he had not dynoed his car since his ignition issues and was posting the best 40-70 times on the forums.

my dyno tune is friday...I will post my dyno info then

j

artguy

in response to dznuts...I had to tweak more than just the housings....also mods to the y pipe and intake plumbing had to be done....

how are you handing the excess oil blow by with your kit dznuts? the BB set does not need as much oil.... m2 modifies the oil lines as well as fabrication of the restictor pill to clean up the problem...

ronarndt

Interesting to hear about the oil leak problem with the M2 turbo. I had debated between the M2 and Pettit "hi-flow" and went with the Pettit. They usually use a rebuilt core to start with, but due to a scarcity of repairable cores, I got a new Mazda turbo, which they blueprinted, ported, radiused and ceramic coated. It cured the oil leak, which was why I needed the stock ones replaced. I would have been royally pissed if I had put brand new M2 turbos on only to find that they leaked oil right out of the box. Hope you get the oil leak problem fixed.

dznutzuk

iTrader: (1)

My turbo kit has no such problems with oil pressure. The y-pipe also had to be longer so we made an adaptor. The oil, water, and air intake piping stay the same. They only had to bent slightly to fit. Really good kit, I could have gotten them from Garrett with BB also but I'm glad I didn't.

dznutzuk

iTrader: (1)

Personally I don't like this idea. I think that if they "Can't take the heat, get out the kitchen" sort of deal with the oil flow+pressure. Adding a restrictor pill or restricting the oil ilne in any way would cause problems I think with oil pressure readings and oil return to the pan+to the engine. Now restrictors would decrease oil flow but increase pressure to them. I used the stock oil feed lines and fabricated new oil return lines which are stainless spiral piping which is a little bigger than stock, everything else stays the same, no problems. BTW are M2's upgrade Garrett parts? What exactly does he change? What does he say about their sizes? What can they be compared to? T22? T25? T28? T30? ETC???????????

artguy

the m2 garrets are ballistic gt30s...the wheels are almost twice the size of the stock units and housings are modified beautifully to fit.....the set is very nice.

the oil restr. pill is used because it is a misting type system that works best with those turbos....the ball bearing twins need less oil than the shaft sleeve bearing stock set....that is why I wonder how you dont change it out....it does not need that much oil...you must I think be getting blow by.

what u got dznutz?...what garret wheels and parts...is it larger than the ballistic gt30s??

dznutzuk

iTrader: (1)

No not larger but not ball bearing either. When a ball bearing cartridge is made the turbo shaft is smaller because of the assembly than regular turbos. So my bearings are bigger than stock, without the problems of bb.

artguy

nothing about probs with ball bearings...I got the m2 set for the spoolup times....and for the power gains.


Ill let ya know how it turns out friday.

j