I just had the bnr turbos professionally installed in my car last night, my mods include dp, cb, walbro fuel pump and thats it. I have the stock ecu and stock intake. The turbos feel good on the primary turbo, but when the secondary turns on it only makes around 3 lbs and is very slow, all hoses/install is done correctly. Oh yeah and the car failed smog today too. Why would these turbos be acting like this? Do I need an upgraded ecu to make them work? Can someone sell me something that will make them work (used)? I've lost faith in my 3rd gen....

Please help...

 

Somone else can proably better answer for you, but I thought that Brian modifies the manifold and removes all of the stuff to run the BNRs sequentially?

You should be running them in parallel, and therefore there shouldn't be any "transition" and no way to fell a "secondary" turbo coming on. You should essentially have two small "singles" working for you.

I could be wrong, but that's my best guess. Someone that has a set of BNRs can problably help you more.

 

BNR stage 1s are still sequential and are essentially stock rebuilds with a ported wastegate and some work done to the secondary turbo/wheel etc.

 

What's your vacuum reading at idle?

 

what's the boost pattern? maybe the professional installer got a line mixed up or something. Is the boost pattern 10 8 then drops to 3 all of a sudden, or 10 8 6 5 4 3?

Tim

 

yeah wingsfan, your thinking of the BNR stage 3's i'm sure. They spool so fast there is no need to run them sequentially, but the stage 1's are still just a basic rebuild so they would be better off sequential

 

no it just gradually looses boost and gets slower on the secondary turbo

 

so when the scond one comes on, its making 8 pounds and it drops to 3 upper rev range? What does the 1st turbo make? The 1st turbo HAS to make 8 psi for the second one to even comes on.

Tim

 

i ordered a remapped ecu, hopefully my turbos will work both fine together now.

 

Hmmm, I don't really believe that will fix your problem.

Have you tried resetting your current ECU?

If the turbos flow better than stock, the worse thing that should happen is a little extra lag hitting boost, but that should be it (from just swapping in the turbos). They should boost just fine with the stock ECU (*IF* everything else is installed and working properly, which it doesn't sound like that is the case).

Do the boost test and post back your results:

http://www.scuderiaciriani.com/rx7/boost_test.html

 

I doubt its the ECU and switching it isn't going to make them run any better. What boost does the car make until 4500...does it make 8 psi or not? After that what happens. Can you hear a loud whooshing noise like boost venting under the hood?
Trouble shoot the turbos before spending more cash in an attempt to fix the problem. Granted an ecu is going to be needed in the car's future, but don't think that it will fix your boost problem. It rarely is the ecu causing a boost problem. I think the installer made a mistake with the hoses.

Tim

 

A new ecu won't make the turbos work better - could be 2 hoses switched around like earlier stated. Could be a solenoid or a number of other things. You could always try the poorman's non-seq if you can't figure it out. If you can't figure it out you could email Bryan to get his opinion - he has good customer service.

 

check the hoses from the LIM it sounds like they are crossed IMO. this site has some diagrams www.fd3boost.com . Sounds like the charge control hose!

-Mancho

 

Yea, I agree man, there isnt much mechanically with the turbos that can go wrong. I'd place my money on the installation. They prob mixed up a vac line, one blew off, or a solenoid is bad. Have your checked all your IC pipes to make sure your dont have a cracked or loose coupling?

Who installed them for you? Was is a Mazda dealer? Do they do a lot of 3rd gen sequential sys work? Did they have a vac hose diagram with them?

STEPHEN

 

If you're boosting fine on your primary then when the secondary comes onlines and drops gradually I would do a quick checkup on your TCA ROD to see if it's still attached. Jack up your car and look at the turbos, there should be a big round thing with a rod hanging out that connects to the turbos. If the C clip broke off and the rod is loose it will cause your sympton. I ran into that problem before, my boost was 10-8-8 then drops to 2 psi as the rev goes up. I reattached the arm and it was fixed. Good luck.