I have a BNR stage 3/4. With stock intake pipe the car runs 8-9 psi. I decided it was time for a proper intake pipe, That replaces the stock intake pipe that has 2 90's and a 45 deg bends. On the stock pipe i also needed to run a reducer from the turbo to the original intake pipe which is 3" to 2.5" or so.

So I put the NEw intake pipe on. Makes the engine bay look WAY nicer --plus the intake was oviously a better functional and i was hoping for some small hp gains.

Go for a test drive. DAMN>>!! First gear.. BROKe the tires loose on a roll as soon as it hit 5,000 rpms it jumped to 8,000. Try to ease it into second gear... but... i get sidesways and end up on the left lane.. WOW..

The intake cant be that good. I thought to myself. SO i procced to try again and keep my eye on the boost guage. this time second gear roll. Around 5,000 again she goes sideways from breaking loose.. DAMN! i just saw 14-15psi.

NO GOOD. I only have 720 secondaries and a walbro.
I double checked my Greddy BC. and everything was still set at 0.
I even disconnected it and still too much boost.
I double checked the hoses on the compressor and they are GOOD.

I start mesing with the wastegate adjustable stem. COrrect me if im wrong.
Extending the stem = less boost
SHortening = more boost? <-- is that correct?

ANyways it didnt make any difference. Still stayed at 14.5 psi. Which ran me 11.00 AFR"S by thew way. on innovative wideband.

I ended up putting the shitty stock intake pipe back on-- it went back down to 8-9 psi. Which is a more reliable setup and runs 10.3 AFR;s at 8-9 psi.

IS the intake that GOOD?> How can i turn the boost down with the intake.

 

Your wastegate isn't big enough! Is it ported at all?

 

Yes its a BNR.. Not sure how big they port it.. but around 35mm i believe.

 

Do you have an aftermarket BOV?

 

I do have a BOV.

 

remove your boost controller and run straight pressure from the compressor housing (not from the intake manifold or anywhere else) to the actuator. Stiffen the adjustable wastegate actuator to lower the boost as much as possible.

If you still creep then welcome to the world of internal wastegates. boost control is very difficult on an Rx-7. even smaller external wastegates can't do it a lot of times. I tried a ported stock wastegate, an HKS 40mm wastegate, and now I have a Tial 44mm wastegate to control boost.

 

Its not boost creep. It really holds 14-15 psi in 1st and 2nd gear.. I have not done third gear because im 90% sure it will boost higher in third. and i dont want this kind of PSi yet. Im happy with solid 9 psi.

I will try changing the hoses of the compresor because ur the second person to tell me to put it direct.

What do you mean by stiffen the actuator to make it boost less.? Hows this done? Extending it or shortening it?

 

http://www.6speedonline.com/forums/9...gate-rods.html

 

Dont over complicate the issue. Just check / replace the hoses on the turbo to actuate the WG. Make sure your Boost controller if equipped is turned open. Still boosting up? Get a bigger WG!

 

Im going to disconnct the electronic greddy BC. Because this is the only reaSON the compressor hoses arent direct.

But the BC shouldnt be boosting because everything is At 0%.

SO FAr the only way to make my boost back to 9 is by using the crappy stock intake pipe.

The new mandrel bent 45 deg. pipe is too good.

 

Try using the stock spring with the TID and see what it does. If it goes over 5.5lbs your wastegate isn't big enough.

 

Try what I did in this thread, it should help lower the boost a few psi to safer levels:

https://www.rx7club.com/showthread.p...=backing+plate

Trust me it works, My car would not boost anyhigher than ~7.5psi on the dyno, when we turned on the boost controller with the haltech we managed to bump it up to ~10-11psi.

 

how do you have the stock intake pipe on a bnr stage 3? The compressor inlet is too big.

 

READ and it says i use a reducer on the BNR. 3" to 2.5 or so.

Its an S5 BNR 3. if it helps

 

Are you sure you have the boost controller setup correctly? On my boost controller 0% duty cycle means that the solenoid is always closed, ie the wastegate does not see the pressure, causing the boost to increase.

 

With the original intake pipe everything works perfect.
I have used it several times.
LO setting: Everything is 0'ed out. = 7-9 psi
HI setting: 40% = 11-13 psi

 

This has been the most consistant and pix ridden post on boost creep i have seen in like 3hrs. Thank you all ,as i am working on a project right now in which i got a S4 TII/tranny,RB downpipe and cone air filter wablro 255. Then i heard about boost creep caused by a freer flow of intake and exhust. This is my second TII but the first in a FB(can hardly wait to drive it.) I got a boost gauge and AF meter to keep a eye on things too. But this information was very useful and you guys are great..in case no one has told you that recently.


P.S. It was nice to read information related to the tread vs and bunch of b!t**ing, whatnot.

 

Now I really cant wait to get my new turbo installed.

 

If it is not a wide band it will do you little to no good.

Get some sort of EMS I believe it is approaching countless numbers the amount of FC's with blows motors because of the RB exhaust and FCD

 

with an upgraded turbo and 720 secondaries, isnt 14 psi safe to run? I say embrace it lol or are you still on stock Top mount intercooler?

 

bigger wastegate is all you can really do.

 

****. Im tried of running around with this gay stocker intake pipe.

ANd yes i do have a stock s5JDM top mount.

YEs 720 second's and my walbro 255 were enough fuel for that short 1st and second gear runs at 14-15 psi. because the wide band showed 11.3 AFR's.

BUTTTT!!! the injector duty cycle must have been through the roof.

and IFFFFFFF i had done a third gear pull it would of gone past 15 psi for sure.

SO if I was dumb and did a third gear i wouldnt have been surprised if it hit 19 PSI and BLEW my motor.



ANd **** the wastegate Its ported by BNR. DOes anyone have more suggestions?

BEcause a simple intake pipe SHOULD NOT BE GIVING ME 7+ PSI AND a 40+HP GAIN.

 

A restricted intake can cause a pretty big pressure drop, but a 7psi difference? lol.

Whats your wastegate sprung for?

 

move the 720s to the primary position and get some new secondary injectors, the walbro is probably fine.

 

Easy problem.. Once you replace the stock TID you are going to induce creep. Just because Bryan ports his wastegates DOESNT mean that the one on the turbo is big enough. I had all kinds of issues with the BNR even though the wastegate is ported. The air STILL has to make a 90 degree turn immediately after the flapper opening.

Only things you can do with creep:

Put supporting mods on the vehicle to ensure safety at the peak creep level

OR

Kill the creep by removing the item that causes it.