13 psi spring and it went up to 17. so i might have to go with a one bar spring

 

it went to 17 without a boost controller?

 

correct at around 6,500 rpms again.

 

What's the wastegate output plumbing look like? How's it routed into the exhaust (if it is)?

 

its venting into atmosphere

 

Did you hook up the EBC to both ports of the WG properly?

 

yup

 

I had the same problem. Long runner A-spec manifold, GT3574, 3” straight exhaust, and a Tial 44mm WG. Nothing seemed to help (I changed between 3 different springs and two different BCs). I finally went to a JGS 50 mm wastegate (much nicer gate IMO). With that gate and no boost control I was able to keep the boost below 17 psi, but I was still creeping; in other words I’d hit ~10psi at 4000 rpms and it would hold there until 6000 then ramp up to 17 by 7500.

I decided to go with a better boost controler (had profec B, then a Hallman MBC). I went with the Blitz Dual SBC Spec R. This has a nice feature for over boost where it applies a different ratio setting if the car hits a pre-set max boost. Well… I never ended up needing that setting; the controller solved all my problems. So in the end, while the larger gate helped a lot (see my thread with the measurements), the Blitz finally solved it.


FWIW, I now have a high flow cat and boost control is absolutely rock solid (no surprise there though). Sometimes even a more restrictive cat-back (RB dual) can help dramatically, especially if the gate is open to the atmosphere.

 

^ If you were creeping with no boost controller, how did changing the boost controller fix the problem?

With a recirculated wastegate and RB catback (catless downpipe) I have solid boost control with a 44mm gate and 13psi spring. I am using my Power FC to control boost.

 

Short answer is that I don’t know; I just kept trying things until they works. Maybe it acted similarly to a stiffer spring (like you mentioned in a previous thread) since it applies some pressure to spring side of the diaphragm. The boost was very unstable (oscillatory) as well as rpms increased, another sign that the spring was too soft (I think).

 

im running out of ideas and patience

 

increase wastegate flow (open your wallet and get better wastegate) or add something that restricts the exhaust, whether it's a more restrictive catback, a cat, a resonator, or whatever.

 

I just spoke to my friend who was with me when I test drove the car after installing the JGS gate (redlining a 500hp FD and staring at the boost gauge = ). He said the boost went from 10 to 13 psi with the JGS gate and no controller. The 17 psi creep was with the Hallman MBC hooked up, then the Blitz EBC cleaned that problem up. Sorry for the confusion. So... the JGS 50mm gate solved it for me.

 

is JGS better then a a ssuatochrome WG?

 

I have never seen an ssautochrome WG, but I've heard bad things about them. The JGS is top of the line.

Here are some pics and info: https://www.rx7club.com/single-turbo-rx-7s-23/50mm-jgs-wastegate-vs-44mm-tial-pics-894682/ (Please ignore my boost numbers in that thread; I changed wastegates, wastegate springs and boost controllers more times than I can keep track of over a three week period. The numbers in my reply #10 are without the MBC; it was not hooked up and I thought it was - in other words the JGS brought my boost down from 20psi at redline to 12).

 

nice, did u have to use an adapter to bolt it up?

 

Believe I said it before but I bet its the wastegate plumbing-mani design. Have the same issue on my mani. Tried differant boost controllers, differant gates (tial and synapse) and still the same issue. Ray Wilson tuned my car and we could not do much fine tuning below 22psi. Thats about the first setting that holds solid. For me its ok. I would look into another mani before you loose a motor!

 

problem is i just had my dp made for this manifold. its a fd manifold im using in my fc,

 

No, the input flange was the same as my previous Tial, however you'd have to get the flange welded in based on your manifold.

 

i have this manifold laying around but again m current dp most likely wont fit

 

One problem I see is that you have a "anti-reversion" step set up in the wrong direction.

Your adapter from the manifold to the waste gate steps the wrong way and kills flow!

Barry

 

wat do u mean steps the wrong way?

 

Possibly a taper could be effective, but a HKS 46mm (or clone) would work best.

Barry

 

Also Im not saying yours is like this. But have a look in the manifold and make sure the WG runners have proper penetrations to the main runners.

I saw a similar manifold that was from ebay and they only had a 12mm hole through the main runners to the WG runners (even through externally it all looked fine) will try to find a pic, its a bit hard to explain.

 

My hks is cast So im sure its real.
Maybe dats y 44mm don't creep cuz they use vbands?