ported WG atill boost creep
The S5 turbo has practically double the wastegate flow potential over the S4. I don't see why it would actually cause that much trouble with good exhaust/intake. And on top of that, a hybrid stock turbo will be able to push higher boost levels effectively anyway instead of dumping heat into the charge. 15psi wouldn't be nearly as big of a problem as it is with a strictly stock turbo. I guess at the high BNR upgrade level that is why they clip the turbine wheel, but still.
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S5 turbo here ported to about a 35mm equivalent, but I also milled out the back plate an 1/8th of an inch to allow the door to open further. 3" TID & 2.5" downpipe, and I have virtually no boost creep.
The other thing that hasn't been mentioned is that the S4 wastegate path only connects to one runner in the turbine housing, while the S5 has separate paths for each.
The other thing that hasn't been mentioned is that the S4 wastegate path only connects to one runner in the turbine housing, while the S5 has separate paths for each.
Thread Starter
Rotary Enthusiast
Joined: Sep 2009
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From: Omaha, Ne
S5 turbo here ported to about a 35mm equivalent, but I also milled out the back plate an 1/8th of an inch to allow the door to open further. 3" TID & 2.5" downpipe, and I have virtually no boost creep.
The other thing that hasn't been mentioned is that the S4 wastegate path only connects to one runner in the turbine housing, while the S5 has separate paths for each.
The other thing that hasn't been mentioned is that the S4 wastegate path only connects to one runner in the turbine housing, while the S5 has separate paths for each.
The S5 turbo has practically double the wastegate flow potential over the S4. I don't see why it would actually cause that much trouble with good exhaust/intake. And on top of that, a hybrid stock turbo will be able to push higher boost levels effectively anyway instead of dumping heat into the charge. 15psi wouldn't be nearly as big of a problem as it is with a strictly stock turbo. I guess at the high BNR upgrade level that is why they clip the turbine wheel, but still.
I'm sure it would, but would it be worthwhile? eh, idk. You COULD try cutting the wastegate's external flapper arm and welding it back together, shorter than before, that way for the same amount of actuator travel you get it to open farther.
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Correct me if im wrong here but since i used a pretty big exhaust valve wouldnt it hit the back plate causeing it to only open a small amount which inturn would basically be like porting the WG a small amount?But if it were to open up more it could use all or most of the 30mm or whatever i have it ported too. Just throwing out ideas to get feedback. Maybe if i can get this issue fixed it will help someone else later down the road as well,
I typed a bunch of stuff but kinda had a lightbulb go off that you wouldn't understand what i was talking about.
Pick up this:
I dont get it. I've known people to slap 3" exhausts and downpipes on their rotaries for a long time now.....atleast 8 years and i cannot count how many i've seen pop due to boost creep. Ported wategate or not, the hot sides are too freaking small.
https://www.rx7club.com/showthread.php?p=9498080
Some of you act like it KILLS you to spend $1500 or LESS (yes i said less) on a decent USED aftermarket setup but can afford to put a $500+ exhaust on your car that doesn't benifit you in any way other than teaching you how to rebuild your own engine? Looks shiny and it's jdm so it must be cool.......
No amount of porting that tiny *** piece of **** is going to keep it from creeping when post turbine gas is able to get away from the engine unrestricted where as pre-turbine pressure could probably build boost on an ht-18 with NO wastegate flapper at all.
Pick up this:
I dont get it. I've known people to slap 3" exhausts and downpipes on their rotaries for a long time now.....atleast 8 years and i cannot count how many i've seen pop due to boost creep. Ported wategate or not, the hot sides are too freaking small.
https://www.rx7club.com/showthread.php?p=9498080
Some of you act like it KILLS you to spend $1500 or LESS (yes i said less) on a decent USED aftermarket setup but can afford to put a $500+ exhaust on your car that doesn't benifit you in any way other than teaching you how to rebuild your own engine? Looks shiny and it's jdm so it must be cool.......
No amount of porting that tiny *** piece of **** is going to keep it from creeping when post turbine gas is able to get away from the engine unrestricted where as pre-turbine pressure could probably build boost on an ht-18 with NO wastegate flapper at all.
Joined: Apr 2005
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From: And the horse he rode in on...
I typed a bunch of stuff but kinda had a lightbulb go off that you wouldn't understand what i was talking about.
Pick up this:
I dont get it. I've known people to slap 3" exhausts and downpipes on their rotaries for a long time now.....atleast 8 years and i cannot count how many i've seen pop due to boost creep. Ported wategate or not, the hot sides are too freaking small.
https://www.rx7club.com/showthread.php?p=9498080
Some of you act like it KILLS you to spend $1500 or LESS (yes i said less) on a decent USED aftermarket setup but can afford to put a $500+ exhaust on your car that doesn't benifit you in any way other than teaching you how to rebuild your own engine? Looks shiny and it's jdm so it must be cool.......
No amount of porting that tiny *** piece of **** is going to keep it from creeping when post turbine gas is able to get away from the engine unrestricted where as pre-turbine pressure could probably build boost on an ht-18 with NO wastegate flapper at all.
Pick up this:
I dont get it. I've known people to slap 3" exhausts and downpipes on their rotaries for a long time now.....atleast 8 years and i cannot count how many i've seen pop due to boost creep. Ported wategate or not, the hot sides are too freaking small.
https://www.rx7club.com/showthread.php?p=9498080
Some of you act like it KILLS you to spend $1500 or LESS (yes i said less) on a decent USED aftermarket setup but can afford to put a $500+ exhaust on your car that doesn't benifit you in any way other than teaching you how to rebuild your own engine? Looks shiny and it's jdm so it must be cool.......
No amount of porting that tiny *** piece of **** is going to keep it from creeping when post turbine gas is able to get away from the engine unrestricted where as pre-turbine pressure could probably build boost on an ht-18 with NO wastegate flapper at all.
Maybe they want stock spool, not the extra lag of an aftermarket setup.
Maybe the world doesn't just work exactly the way you think it should, because if you spend any time reading Corky Bell you will find that he complains about boost creep on most all setups, even his current Miata's.
Here is a thread from a creative guy who has a tight budget. He now has NO boost creep, and stock spool. Why, he could even go with a hybrid turbo with no clipped exhaust turbine. In this thread you will find a link to yet another solution to the problem. Creativity is about to overcome all your objections. Don't live in the past.
Thread Starter
Rotary Enthusiast
Joined: Sep 2009
Posts: 884
Likes: 0
From: Omaha, Ne
I typed a bunch of stuff but kinda had a lightbulb go off that you wouldn't understand what i was talking about.
Pick up this:
I dont get it. I've known people to slap 3" exhausts and downpipes on their rotaries for a long time now.....atleast 8 years and i cannot count how many i've seen pop due to boost creep. Ported wategate or not, the hot sides are too freaking small.
https://www.rx7club.com/showthread.php?p=9498080
Some of you act like it KILLS you to spend $1500 or LESS (yes i said less) on a decent USED aftermarket setup but can afford to put a $500+ exhaust on your car that doesn't benifit you in any way other than teaching you how to rebuild your own engine? Looks shiny and it's jdm so it must be cool.......
No amount of porting that tiny *** piece of **** is going to keep it from creeping when post turbine gas is able to get away from the engine unrestricted where as pre-turbine pressure could probably build boost on an ht-18 with NO wastegate flapper at all.
Pick up this:
I dont get it. I've known people to slap 3" exhausts and downpipes on their rotaries for a long time now.....atleast 8 years and i cannot count how many i've seen pop due to boost creep. Ported wategate or not, the hot sides are too freaking small.
https://www.rx7club.com/showthread.php?p=9498080
Some of you act like it KILLS you to spend $1500 or LESS (yes i said less) on a decent USED aftermarket setup but can afford to put a $500+ exhaust on your car that doesn't benifit you in any way other than teaching you how to rebuild your own engine? Looks shiny and it's jdm so it must be cool.......
No amount of porting that tiny *** piece of **** is going to keep it from creeping when post turbine gas is able to get away from the engine unrestricted where as pre-turbine pressure could probably build boost on an ht-18 with NO wastegate flapper at all.
SERIOUSLY?? stupidist damned advice I've ever heard.. add a bunch of performance enhancing devices, then weld RESTRICTORS to cancel them out so you can control boost. WTF?? Yeah, go ahead and downgrade every thing you've done, screw doing it the right way and maintain performance.. REALLY? You think a free flowing 3" exhaust with RESTRICTORS performes better then stock 2.25"?
~Mike...........
~Mike...........
I bought a $170 WG and 10 dollars in metal. Then welded restrictors ( to keep my engine from going to **** ). The only thing that got canceled here was the over boost.
I dont know if a 2.25 stock exhaust flows better or not....whatever. Never had it.
Also, not everyone has disposable income to build engines the best way possible. If that was the case, florotoary wouldnt be asking how to fix his problem. Instead he would be buying a complete turbo upgrade..
Nice job porting the gate. I have a failsafe solution to your problem. Take the back plate off the turbo, cut a hole out where the flapper is and make sure the flapper when it opens actually opens further then stock and into the new hole you just made. Now weld a tube over the hole and plumb that back into your down pipe 18" or so further downstream. Now make a little divider and weld it to the backing plate effectively separating the turbine discharge hole from where the waste gate used to flow into the same hole. This solves a couple problems. 1: Being it allows your flapper to open farther. 2: It gives your waste gated exhaust a straighter path instead of the hard 90* out the flapper hole, then 90* out the down pipe. 3: It also keeps high heat and velocity of the exhaust existing the turbine from inhibiting waste gate flow. It also enhances turbine discharge if you port the turbine discharge to be shaped like a smooth cone from the turbine wheel to matching diameter of the downpipe. I've suggested this to several friends over the last 10 or so years and all of them it worked and they had rock steady boost of 7 psi on large hybrids running 3" or larger exhaust running after market EMS so no TID. My buddy DCEE on this forum did it about 7 or 8 years ago, you might be able to find his write up. He has a 13b turbo'd 1st gen with a T04E hybrid.
~Mike.............
~Mike.............
Interesting.......See I did something like that exept I pitch the flapper door and the actuator to the garbage....and I still had over boost untill I welded my RESTRICTORS. There is one on the top of that crush bend and on the bottom...
This guy has a stock turbo.....
Fuel upgrade will keep your engine a little safer but your little turbo wont last long overboosting all the time.
Originally Posted by SirCygnus
sigh. just run a stand alone ecu and never worry about boost creep.
i run bnr stage one and it creeps all the time. so what? haltech compensates for it and i find it more fun.
i run bnr stage one and it creeps all the time. so what? haltech compensates for it and i find it more fun.
I realized that my first attempt with using an exhaust valve was most likely not opening far enough. Durr hurr hurr. I had to extend the actuator rod nearly a 1/4" to reach the closed position of the flapper. So I cut and ground all the extra crap out, making the flapper arm go pretty low. I think it came out well. I was so sad, though, the port was so BEAUTIFUL before I started welding. All shiny and ****. I have a 30mm port now, before it was around 24mm, and it opens farther. It doesn't seal perfectly, but it ought to get the job done quite well. .5mm gap or less. Anyway, I put her all back together last night, but I haven't driven it yet because my driveway is a ******* mud pit. It's not enough that the snow is starting to melt, it has to RAIN, too. Bah.
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I finished the waste gate port yesterday. I STILL creep a little in 4th gear. I have the stock actuator hooked up, no boost controller, so it's as low as it gets without disconnecting the rod and leaving it open all the time. I can run WOT through 3rd hitting about 10-12psi then in 4th it'll try to go to 14-15psi. Haven't fiddled with 5th yet, but it won't be any better. I'm disappointed, but it's a lot better than it was. Just go S5. This **** is ridiculous.
I finished the waste gate port yesterday. I STILL creep a little in 4th gear. I have the stock actuator hooked up, no boost controller, so it's as low as it gets without disconnecting the rod and leaving it open all the time. I can run WOT through 3rd hitting about 10-12psi then in 4th it'll try to go to 14-15psi. Haven't fiddled with 5th yet, but it won't be any better. I'm disappointed, but it's a lot better than it was. Just go S5. This **** is ridiculous.
also how much psi were you using in the video? what if you shortened the wg lever so it opens more at lower boost. when i tested my wg actuator, it really didnt get to full travel until 15psi. at stock boost it was only half-way open. or if you found an aftermarket actuator that had more throw?
Yes, that's just the waste gate spring, no controllers. I tested it with 10psi, then 15psi. I don't remember which I used for the video, but I do know that it didn't open any farther using 15psi, so it doesn't make any difference for mine. I do realize I should have tested it at about 7psi, but I don't know what I would have changed if it wouldn't have opened all the way at that pressure, except maybe modify the lever like you mentioned. Kind of wishing I'd done that because there's room for it to open at least another 1/8" at the tip, and I now know that it just barely wasn't enough.
An aftermarket actuator sounds like a decent idea to me, especially in your case. But I think I'm going to leave mine as is for now. It's basically safe to flog through 3rd gear and almost completely for 4th. I don't want to take the turbo out a THIRD TIME if I'm not replacing it with something markedly better.
An aftermarket actuator sounds like a decent idea to me, especially in your case. But I think I'm going to leave mine as is for now. It's basically safe to flog through 3rd gear and almost completely for 4th. I don't want to take the turbo out a THIRD TIME if I'm not replacing it with something markedly better.