Primary turbo replacement -- how to?? + my dyno experience
 

Spent about 3 hours with Chris today @ rotary performance getting my car tuned. As expected it was pig rich. Initial dyno hp numbers were pretty low. 240hp! and Chris said he typically sees 300 hp or more with my mods. He changed the plugs as the richness fouled them in only 1500 miles. Then he couldn't control boost and he asked me if I bored out one of the pills and I said no, but sure enough the previous owner did as a precaution as it didn't have many mods.

Once he replaced the pill he was able to get control of the secondary turbo but couldn't get the primary up past .80 - .82 range.

After 25 runs (yes 25) he was able to get it up to 280rwhp. He felt that everything was running right, but the primary turbo was getting tired. (He couldn't get it to respond to any base duty changes.) (I speculate that even though my car has only 21k miles that the previous owners and myself have done a lot of short trips, frequently engaging the primary turbos.

My question is.... how can I cost effectively change only the primary turbo? Where can I get a replacement and
is there a "how to" on the install? I'm thinking I can do it myself as it is the primary and easier to get at.

Oh yeah, the 280hp was at .9bar on my pfc.

mods include:

pfc,cb, hiflo cat, efini pipe, dp, apexi intake, greddy smic

Just go non-sequential.


R.K.

I was thinking that, what do you think the benefits would be in my situation?

Eh, sorry man...no real 'easy' way to replace just the primary turbo. I'd recommend just taking the whole assembly off and inspecting the whole thing. Doesn't make much sense to go to the trouble of changing out the primary without even looking at the secondary. How do you know what kind of shape the secondary is in?

Besides that, I don't think you're gonna be able to get just the primary rotating assembly used. You'd more than likely have to get a whole set, which at that point you're just buying a set which could go to shit on you real quick. You have no idea how a used set of turbos was treated.

I'd say pull the whole assembly and have them rebuilt by BNR or something.

Hmm... Chris said that he could pull the primary replace the cartridge and reinstall for $1000. Obviously a lot for a repair - to me anyway.

I could go bnr's or per chris the efini spec's (which btw, he prefers as the BNR's "leak oil"). Suppose the efini's also have improved the manifolds??

If I bought a whole set -- could I install it myself? Where can I get a how to? I've pretty much removed everything surronding the turbo's (efini pipe, exhaust pipes, etc.)

If you bought it new you can replace it no problem. My buddy did it himself in 5 hours in his house garage. If you are going to buy new then go non-sequential and use up the turbo life and have fun. The advantage to non-sequential is that there is no boost spike at transition, easier to control boost and more linear power band. Besides you are using both turbos at the same time all of the time. The only down fall is turbo lag but with your mods it won't be such a big deal. Do a search for non-sequential convertions. Its pretty easy and you will notice that a lot of guys are non-sequential. I feel thats its a lot safer because if you are going through a turn a you lay on it then when the turbos switch over there will be a good chance that you will lose the back end and possibly get in a accident.

R.K.

You cannot just replace the primary the whole unit has to come out and then you can change the cartridge, which IMO shoud be done by a professional.

The removal/intall of the turbos is very painfull on jack stands but can be done. Make sure you buy all the studs, bolts, gaskets ahead of time. It not difficult just involves removing alot of stuff.

Here is a quick summary:

spray pb blaster
unbolt the downpipe from the cat
remove intake
remove both intake pipes
remove y pipe
remove rear part of y pipe
remove rear intake inlet tube
unbolt downpipe from turbo
unbolt turbo manifold and pull the turbos out

I had a 300zx tt modified with the jwt chip and had 300 rwhp and didn't like the spike of the non-sequentials coming on. I like the smooth (or relatively smooth transition of the sequential).

Do you have a link for hints on the install?

psi4psi - thanks for the insight - honestly it doesn't sound that bad. I mean if I am going to save $500 it may not be a bad idea. I have a daily driver.

I've taken all those parts off before and it is rather easy just not the turbos.

anyone else?

Did you get your terms backwards?

The seq. system has 2 violent jerks when the turbos are engaging. Non-seq. has a slowER 'jerk' to it with no secondary 'jerk'. Non-seq. would seem linear.

I'll be facing this soon as well. I've never heard that the BNR upgrade caused the turbos to leak oil. I need to look into that before I do the upgrade.
I know the Gotham guys like to go non-seq after the stage 3 upgrade. From what I hear gives almost no lag and linear boost.

The oil thing was on the first sets that came out. At least on the 1st set that Rich got on.

Talking to Bryan last week all of that has pretty much been solved.

What's the point? Just go single if you want non-seq.

The original oil problem came from having too much oil pressure at the turbos. This has been solved by modifying the hole size on the banjo bolts. This should no longer be a problem. We've had no further issues with the current setup. BNR is pretty thorough with his work. Just like anything else the first run will always have a few bugs to work through.
:D

I agree, single is the way to go, but not everyone can afford it. $3-4K just for the turbo kit, then all of the supporting parts...it adds up in a hurry. Just a thought. You might want to go to http://www.jt-imports.com/MAZDA%20FD%20JDM.htm . Scroll down to the bottom and there are used stock turbos with less than 25K miles for $525. Probably the post '99 turbos too.

Sent you a PM.

If I bought a whole set -- could I install it myself? Where can I get a how to? I've pretty much removed everything surronding the turbo's (efini pipe, exhaust pipes, etc.) [/B][/QUOTE]

hey brentis, it's very doable ( is that a word)... i took off my old turbos and swaped on a used set without much problems.. you have to get new bolts and stuff....robrobinette has a good write up on how to take them off or refer to the service manual. it just takes time and patience....lots of bolts are hard to come off. you can use pb blaster and it makes it easier to come off. besides that not much trouble.. you have to take the air pipes off and when you put the turbo back on the gaskets are hard to line up.... shouldn't be that hard with a little help...i did the whole job solo so it was that much harder... good luck...you can buy more goodies with the labor you save. l8ter.

Brentis, I would shy away from BNR since you don't get your speicif turbo's back. He has them already made to his specs and once he gets yours, he then sends a set out. Seeing how your turbo have 21k on them, versus the average turbos he receives that have 60k+ and cracked everything.

The 99 spec twins are said to flow better than our turbos. Might be worth a try ...

Good insight Ray. Now that I am thinking about it, I'm not sure the turbo is gone/going. I read exstensively last night and found that our cars need the pill in the pre-control.

Seeing how my car had a bored out wastegate pill (unknown to me) I anticipate that the same precaution was taken for the primary turbo. Further, Chris was having the same exact problem with the secondary turbo. I asked him if it was possible if the primary was having the same problem and he said that "both the primary and secondary share the same wastegate". While true, the primary also can loose boost if the precontrol pill is bored out/removed. -- Here is the referring link detailing what I read -- https://www.rx7club.com/forum/showth...+turbo+problem

So what do you think??