How big is your port? I have a decent size port and hold 15 to redline with the medium actuator.it wouldn’t want to hold least than 13 in the higher rpms

I have the IRP manifold and have no creep issues. Large streetport and EFR 8374 with a resonated mid pipe and RB dual tip. Graphs showing boost are in my thread.

That RB Dual dip is probably creating enough back pressure to keep the creep down. My exhaust is 3", no resonators and no cats. I'm going to throw in a restrictor or a high-flow cat to see if it reduces creep.

Healthy stock port FD Rx7 with our cast EFR IWG 8374 kit, pump gas, full 3" exhaust( no cat), medium BW actuator. 4th gear pull, holds 11~psi. See attached datalog. Please note this car does not go WOT until the midrange. I have since tuned it with the controller on, and it sees about 16 psi by 2900rpms( not fully ramped up all the way, but close).

And on the flip side recently Luck7Racing bought a 8374 IWG from us, and the customer wanted the turbo up higher. We don't make a " long runner" IWG manifold for the FD chassis so someone else built the manifold. On pump gas with a large street port, 9.4:1 rotors, and 3" open exhaust it crept up to 16.5 psi on the top end. I advised them to remove the T4 divider and WG divider in the turbine housing and the boost dropped to 7.5 psi through the entire rev range on their dyno( 4th gear for both before and after). No other changes besides porting. I tuned it in person and it made 353rwhp on pump only at 9.3psi. At 15psi it made 426rwhp. As I've said, and seen before the manifold design does not affect the creep, its solely based on WG flow in the turbine housing, size of the exhaust system, and how much the engine is flowing.

Hi , Thread resurrection - I have to disagree on fault placed on the turbo as i know what is causing my latest set up to Creep, I have previously been running a custom made turbo manifold with the standard efr iwg 8374 with a 3-inch downpipe for over 2 years absolutely no problem, this setup held boost rock solid at just under 15psi with the 2 x 7psi gate springs installed in the turbosmart Dual Port IWG75 actuator with the boost control turned off. I recently decided to Upgrade to the CAST Turblown Manifold to be greedy and try scavenge 100 rpm or so spool increase by running the short runner stubby cast manifold from turblown, But now i have developed heavy boost creep.

The only thing that has been swapped out is the Turblown Manifold and the Turblown 3inch downpipe that i purchased. I am really not sure where to go from here as i certainly won't be grinding away at my turbo housing when i know my previous setup had absolutely Zero boost creep.

15psi on your old manifold was already "creep" or at least high threshold, I'd say your option is to go back to the old setup, or port the housing. What's the old manifold look like?

Interestingly, I had a motor go low compression (80psi), and it slowed the spool down (3500rpm for 15 psi from about 28-900), and made the car feel a little "flatter" overall, but it did nothing to the boost threshold. Still the same 12-13psi on spring pressure with ported housing.

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I had no boost creep at all, the 14psi spring held the boost from low rpm right through to redline, i say 15psi as that's what my mechanical boost gauge said but it was spring pressure.

Are you sure you didnt mis align the actuator with the re install ?

Is the tune over soft? Ie super rich and not much advance ? This causes creep, happens on all engines as you basically antilag the engine...

Hi, er well my tune is 10.9 afr with 15 timing at the moment but i start to creep at 5500rpm

it could be in the tune i suppose now the manifold is different for sure

I am going to try and re-clock the turbo housing and actuator and compare it against a stock mounting position considering the actuator bracket enables you to install the actuator where it's not designed to fit as i pulled the whole lot off yesterday so i may aswel have a mess around.

This is flawed logic. Your entire powerplant setup is a synergistic system, if you start changing one you'll have to investigate the faults of another. The ecosystem of your intake/exhaust/etc has been changed and is now out-flowing the capabilities of your IWG. In essence your wastegate is the little fat kid. Want him to keep up? Slow down (restrict your exhaust) or make him lose weight (port your wastegate).

Before you go clocking your turbo, etc., just wire the wastegate door wide open and go for a drive.

Another customs was just on the dyno this morning. Full cast 8374 IWG kit, pump gas, 3" full exhaust, large streetport. Held 10 psi. 15 psi made 450rwhp on a mustang dyno; Adaptronic modular remotely tuned by Shawn.
https://cimg1.ibsrv.net/gimg/www.rx7...3c06317b1a.jpg

how much of this have to do with boost control strategy?
perhaps closed loop control with proper PID tuning will make a difference on the IWG setup?

9174 Cast IWG kit ( full 4" exhaust, half bridge). 14.5psi turbosmart actuator. Zero creep. 528rwhp @ 15 psi( pump with meth) Adaptronic FD PNP.


https://cimg0.ibsrv.net/gimg/www.rx7...de7b85ad31.jpg

I’m running closed loop boost control and am holding 15psi quite nicely. I have a fair bit of preload on the wastegate actuator as well.

Not to slam Shawn on here, but that setup should be making quite a bit more power on the bottom end. There's a few things he should be looking into for the tuning with immediacy.

I had creep issues with 8374 iwg and 3,5" straight pipe. it crept to 1.3bar (19psi) by 5500rpm even if i wired the wastegate full open.
What i did was that i removed the divider leading to the wastegate without touching the manifold flange much. Enlarged the hole between the 2 runner around the same size as the wastegate. After that it was 0.8b (11psi)all the way to 8krpm without any noticeable difference in spool or anything.

Here is some pictures. Hope this helps people that have similar issue with these turbos.
https://cimg4.ibsrv.net/gimg/www.rx7...88a854f875.jpg

https://cimg9.ibsrv.net/gimg/www.rx7...ed5def5df9.jpg

Hi thank you for this, As suspected Junk manifold design. Looks like i am going to have to do the same , have you got any more photos from any other different angles of the work you did? Its a shame to have to butcher up a $650 manifold because they don't work properly for the iwg efr application they were sold for.

Sorry forgot to mention that im running a manifold that i made myself. I dont want to talk down anyones manifolds that i havent seen or tested in real life.

I believe that the boost creep comes from the turbo exhaust housing design. There are reports of boost creep in piston engines also.

Porting the wastegate is pretty straight forward. Remove the housing. Grind away the divider leading to the wastegate until you think it flows well. Just a regular day with a 2k$ turbo.

We've recently had 3 more customers finish up their 8374 IWG tunes, and all of them held 11-13 psi to redline in 4th gear( 3" full exhaust).

3.5" or bigger will always cause boost creep, again same for the VAST majority of all EWG setups too. Anytime the turbine wheel can really breath, its puts more demand on WG flow( as long as you aren't turbine wheel/compressor wheel flow limited).

Just to be clear and to make sure people don't mistakenly agree with you, you're not looking at the manifold, you're looking at the turbo/turbine housing itself. In the real world (in my opinion) manifold design isn't really going to do shit on an IWG systems propensity to creep, what will are all the left over casting slag, core shift, and hard edges etc in the casting process.

Read: If you're going to run an IWG at the LEAST pull the turbine housing off and take the worst tool known to man (Dremel) to it and spend a couple hours smoothing the wastegate path even if it seems like you're not gaining much.

This is my semi-heuristic ( I have a flow bench, and try to always do some sort of rudimentary comparative analysis on parts meant to flow though its far from an optimal protocol) approach to the IWG vs EWG debate so don't take it as gospel.

Manifold has a huge impact on internal wastegate turbos in my experience.

Had 60-1 hifi with p trim exhaust wheel in S5TII manifold and bored out exhaust housing. Crazy boost creep on my 3.5" exhaust. Ported wastegates, added 60mm external wg with huge wg ports- still creep. Ported S5 exhaust manifold to reduce the velocity stack and ported turbo housing as well up to the wastegate runners- boom, no boost creep.

Cast IWG shorty manifold does also have some velocity stack off of the exhaust ports would have to port manifold and turbo exhaust housing up to the wg runners to lower velocity so exhaust can turn out into the wg runners.

We have differing experiences. I've just ported the turbine up the the gate runners and seen the same.