This may seem like a stretch, but how are your plugs and/or wires?
I know that at one point I was showing my normal boost, and definitely NOT getting it, and it was because my plugs were bad. It also messed with my vacuum readings I believe.
Hope that helps.

 

what about the turbo control solenoid?

i'm on twins and mine had some lag and lots of chugging when it was cold. after i replaced that solenoid the car was more responsive and alot of the cold chugging went away.

 

a t78 seening full boost at 3800rpm?

when did your t78 se full boost? what kit did you run?

 

Ok....my plugs are new and I have new wires in my garage, just not yet installed. I doubt it is the plugs...it runs fine, just runs slow and boosts slow. But I have a fresh set of plugs and wires here, I can swap them and see....just seems doubtful. But at this point, anything is possible.

The turbos were brand new when I bought them....the guy had changed his mind after he bought them. They still had all the blue ink writing on them from BNR, never been ran before.

I checked my boost and rpm:
1st gear - 10psi @ 6000rpm
2nd gear - 10psi @ 5500rpm
3rd gear - 10psi @ who cares....never gets there anyways...I didn't have any stretch of road to go 100mph on....so I didn't bother.

I have a boost leak somewhere....or a clogged cat...one or the other...but something is slowing my response down big time. That is why it feels ok passing...it still pulls good at 10psi, I just don't see 10psi for but a second while driving...all the rest is the slow buildup of boost getting to 10psi....so until 4500rpm or so...I am below 5psi...slowly building. Then when I shift, I lose all my powerband and the car barely chirps the tires between gears.

I have not yet checked all my lines and couplers, but I will do that tonight, and then if that doesn't fix it, I guess I will buy a MP and a PFC ASAP.

As far as the TCS, I doubt it....it runs fine, no hesitations or misses....just some slow *** spool which leads to a slow *** car.

 

after everything youve mentioned im going to take a guess and say its most likely either a clogged main cat or a rather large boost leak.Do you still have the stock y pipe? if so check the coupler that hooks up the y pipe to the crossover tube.When mine developed a slit it was venting boost in copious amounts and I was experiencing the same symptoms come to think of it.

 

I used to not have a stock y-pipe.....or at least the crossover tube part was not there....I was using the M2 Large SMIC which bypassed the crossover tube...but I had to buy a used crossover pipe to go with the Greddy FMIC. But yeah, I agree....it's got to be one of those two things. I can't see the turbos sucking that much ***....and I doubt my motor just all of a sudden has **** for compression since it starts fine everyday.

I will check the crossover pipe for cracks as well...something is off....I just got to find out what.

Thanks,
Scott

 

yup I agree.Check the crossover pipe and the couplers.If you are experiencing primary boost problems then its something much simpler to diagnose.Its usually a coupler or a vacuum hose.Have you checked all the actuators by any chance? the ones underneath the car?
the turbo control actuator,the wastegate actuator and the pre spool actuator? you may have a missing c clip thats causing issues.Yes thats it.Check the wastegate actuator rod.It may be the culprit also.Although when mine fell off it was pretty much like driving a naturally aspirated fd.

 

I am non sequential so alot of those solenoids are not in use anymore. I don't think it could be the wastegate actuator...unless it is venting the entire time I am boosting.

I don't think it could, but could it be an intake leak, before the turbos? I don't think that would cause it, but these damn Greddy Intakes are built thinking you still have the stock airpump...which I don't, so I simply had to cap off those extra pipe/nipples...and they are somewhat loose. I checked my couplers, they are all brand new from the FMIC kit...and don't appear to be cracked anywhere. I am going to reinstall all the pipes and see if I can't get them to seat a little better though.

The engine is still too hot to really investigate though since I just got home about 45 minutes ago.

 

if it was a boost leak and the turbos did make it to 10 psi i would think it would be squeeling like a pig and you could hear the boost leaking. sounds like a slow spool. you were NS before?

 

Yeah...I was NS before....and I don't really know what I hear while it is boosting....the intake is either really loud, or I hear a boost leak. Not a squeeling sound....more of a sucking sound.

I did use to have the flapper door....but no way that made this difference. There is a huge difference from hitting 10psi at 2800-3000rpm...as opposed to 6000rpm....I spool like I am trying to turn a Thumper. I mean, my T78 spooled 10x faster than this. Something is definately wrong...just don't know what yet.

I have removed all my IC pipes and checked all my couplers..everything seems good. A few were somewhat loose and not quite fitting perfect. I fixed that, tightened them all back down, but have yet to take it back out for a drive. If that is not it, then it is either my stock car causing too much backpressure on my turbines slowing down the spool...or I have a leak somewhere.

If it is the turbos, that would be the most disgusting worhtless investment of my life.

 

Took it out tonight for some cruising/messing around....still slow boost buildup. I guess I am going to look for a MP and a PFC now...and if that doesn't do it, then I may have to remove the turbos and checked for a cracked manifold....but wouldn't I hear that? It doesn't make a whole lot of noise while boosting....just some slight suction sound...from the intake I assume.

I need to get it on a dyno so I can boost it and have someone check under the hood for any leaks.

There is a big RX7 meet around here tomorrow, so maybe someone there can give me some suggestions or opinions after riding in it. Do you think it could be my BOV or Manual Boost Controller? Both were fine on the stock twins...so I don't see how they could be bad now....but could I have installed the MBC backwards? Or would it just not work at all if I installed it wrong. It controlls the boost as it is, just really slowly.

Oh well....still runs fine, thats a good thing at least.

 

you said you didnt have your air pump anymore right?
Do you still have the air control valve in place? Its the piece that attaches to the side of the lower intake manifold.Its basically right above the fuel rails/injectors.
I had slow spool up when the gasket to this thing wasnt aligned properly.
Also.if everything started to go wrong once you installed the new bnr's then maybe its the twins themselves or something that you had to remove in order to install them.Keep checking there.Think about everything that you had to remove.You will find yur answer there.Also why would someone sell them unless maybe there were some issues with them.Just a thought.
I remember when I changed out all of my injectors.Big pain in the ***.Once I finished I could get any secondary boost.I hunted for the problem for a month and finally I found out that my ccv solenoid vacuum line was cut.I was working in that area so it only makes sense that it was something I did.

 

Move boost gauge vacuum line to the y-pipe manifold. See what the positive pressure is there. If you're seeing a huge difference, you have a boost leak.

 

aha.I forgot about that one.good advice clayne.

 

It's not the following:

Main cat. or downpipe.

They were working fine before you installed the new turbos and will continue to work fine for the time being.

As far as the turbos go, I highly doubt they're the issue. To me, it sounds purely like a boost control or leak issue.

When do you see 7 psi BTW?

Are you using the same vacuum lines from the compressor side to the WG actuator to the WG solenoid? Or did you swap them out with new ones? (pills might be an issue here)

Please check ALL vacuum nipples on the turbo manifold, as well.

 

Thanks for the tips.....I will try to move the boost gauge line as well as check around the ACV.....it couldn't be the air pipes themselves could it? The ones that used to go to tha airpump?

I don't see 7psi till a little before I see 10....maybe 5000rpm..I never really paid a whole lot of attention.

The vacuum lines are all the same lines I had on my stock twins....simply removed them from that setup and installed them on this new twins. They were newer silicone lines already from when it was first turned non-sequential.

I wonder if my weld didn't hold on the exhaust manifold from when we removed the flapper door out of it. I took it to a shop to get welded....and they said it couldn't be welded, and that it has to be some nickel rod something to hold because of the material that the exhaust manifold was made of. This guy builds Off road firetrucks for a living, a friend of the family, and has been welding since he was 2, seems like. He said it would never come off...and that that was the only way to even weld it...if it did fail....could that be the cause? The more I think about it, the more I doubt it....I would hear a huge hold in my exhaust manifold....it would be like running with the O2 sensor out of the bung.

Just thinking of **** that has changed since before.

Thanks again for all the help guys....hopefully it will be a simple fix when it's all said and done.

Edit: About the cat....when the old turbos blew and started dumping oil/coolant into my exhaust...I wasn't sure if all that residue may have clogged it, making it different from before...because it never had all that smoke and crud pumped through it.

 

Remember that if you're producing less boost you'll also be producing less back-pressure which will be producing less boost, etc.

Like I said, route the boost gauge sending line to the y-pipe (preferrably in the center of it).

This will give you much better visibility.

As far as the cat. goes, no, it'll be fine.

It's not the ACV either. The air pump has a split path from the intake (in a stock configuration) anyways.

 

not to be a devils advocate:

But it could be the Turbos.

There have been many horror stories about
rebuilt twins from BNR.

See if anyone got any spare stock twins in decent
condition they can let you borrow. and switch them
out, and see what happens.

goodluck

 

The only thing on the turbos that would cause that would be severely worn exhaust side turbines. I'm sure they were examined beforehand.

 

Hello all.

I was just checkin in on the forum. Why dont you guys get ahold of me when you are having issues? Come to me and I can help you out. Running 12 inches of vacume at idle tells me that you have low compression or an intake leak. Once you know your compression and look for leaks, or if you can't find the issue, call me. My number is 205 640 1193.

Bryan
BNRsupercars@aol.com

 

yeah, I'd agree with Bryan on this one. 10 or 11 on the vacuum side with a stock ported engine means something amiss. Have you had it compressioned checked lately?

Tim

 

Just seems odd that I would have low compression as soon as the turbos were installed...because prior to replacing them, my vacuum was always around 17mmhg or so. I am removing my UIM and all that and I am going to check all the lines....I have checked the couplers, and have yet to switch my boost source line to the Y-pipe...which sounds like a great way to check.

I am guessing it's a leak...but I carb cleanered the hell out of it, and never noticed hitting any spot that effected the idle at all....I will run a compression test this week just to make sure....but that would be too odd, that it would just up and quit the same day. Maybe if I was running it hard or something....but I simply went out to start my car up one morning, and smoke...blew the turbo seals somehow.

I didn't get ahold of you because I don't really believe that it is the turbos fault....just something associated with the installation, which is a pretty simple install....so I don't see how something could be wrong....I was really posting out of curiousity about the spool up characteristics of these twins.

 

LC,

Move boost gauge to y-pipe before removing anything.

This will tell you what you need to know to go to the next step.

 

Not wanting to be a bearer of bad news and hoping that I'm wrong BUT is it possible the guy bought them new, put them on his car and poped the engine right off the bat? The apex seal would go thru the turbine wheels and desrtroy them making it spool REAL slow.....just a thought that no one else mentioned. And honestly the seller might not have even known it would be damaged....it happends all the time.

Also, you need to check out for those vac leaks cause if your vacume dropped then its definatly going somehwere.....SOMETHING had to cause the vac to drop....it would have to be after the tb and wouldnt really be turbo related. Did you put the uim gasket back on?

Oh yea, let me make a suggestion.....dont run your car in boost right now..... for you to hit 10psi with some type of leak or problem you more than likely over spinning your tubos like crazy and you can damage them.

STEPHEN

 

Ok....I swapped the boost gauge line over to the Y-pipe....it seems to spool faster now and it goes up to like 15psi before I let off thinking...oh ****. So...what I see as 10psi is at least 15psi at the Y-pipe in a much faster pattern, or so it seemed. I didn't like not having a vacuum gauge while it was hooked up over there...and I didn't want to press it any harder to find out how much boost it really is pushing. But 15psi was at like 6000rpm in 2nd...and I let back off.

It smoked about 1 minute after I started it up....smelled like it was dumping a ton fuel into the exhaust, had a grayish tint. It lasted for about 30-50 seconds and then went away....but I did notice it in the rearview when I began to accelerate...kind of like little puffs...like compression strokes. It seemed to let up after driving a bit....it just did it a bit after startup, and then for about the first 1/8 mile while driving. Does moving the boost gauge have anything to do with that? Or did my car just decide it wanted to smoke fuel all of a sudden. Wasn't doing any of this smoking yesterday...but this was the first time I drove it today after I swapped those lines.

I capped off the UIM nipple....and simply moved the boost gauge into one of the Y-pipe nipples. The one right below the CRV (other BOV)...I used to have 2 nipples on the Y-pipe looped together...so I removed the loop, capped one side, and inserted the gauge onto the other side.

I am going to switch the lines back though....I know what it does now when hooked up there. Now I just need to know what that means...boost leak? or is it normal for it to read that much higher...I know the IC may have some pressure drop, but I can't imagine it losing that much...but then again, I don't know.

And as for the UIM...no, I have never removed it....the only pieces changed/touched while swapping the turbos were the intercooler, intake, turbo, dp, and exhaust manifold. Nothing was removed or touched past the Greddy Elbow.