25psi on e316g

[95eclipseSlow]

What do i have to do to the internal wastegate on my evo3 16g in order to boost it to 25psi?

 

[JusMX141]

This:

http://www.dsmtuners.com/forums/tur...oking-strong-internal-wastegate-actuator.html


If your turbo has a stock 31mm flapper, there's a good chance you can get it to make over 25psi for an instant, but it'll never hold it.

If you have the 34mm flapper, there's a good chance you'll never make 25psi without the flapper blowing open.

 

[95eclipseSlow]

can you make one for me? please? i can send you the wastegate off of the car now.

 

[pboglio]

Hmm, thats odd. Mine will hit +30 psi plus and then bleed down to about 21-22 psi at redline. I am on a bone stock wastegate with no wastegate port work though. However, I definitely will agree a stiff internal wastegate is great to have, as long as the spring is upgraded and your not using too much travel from preloading. Damn, now I gots to have me one

 

[daren_p]

Easiest way is to just unhook the boost source to the flapper You'll probably see 30psi or so spikes but eventually level out around 25-26psi as the rpms increase

A couple shims under the WG may help it stay closed abit longer, just be careful of boost spikes, if you shim it too much. Back when I had an evoIII, I ran a couple washers under each WG mounting point, just because.

An external gate would be your best option, but thats defently the more expensive route (though once you've ran external, you'll probably never switch back)

 

[JusMX141]

can you make one for me? please? i can send you the wastegate off of the car now.

Sure can. I currently have two Holset actuators at the shop that can be used to turn OEM Mitsu actuator into one of mine.

Mine will hit +30 psi plus and then bleed down to about 21-22 psi at redline.

This is happening because the actuator doesn't have enough spring tension to pull the flapper shut again once the airflow begins to pass through it.

A properly functioning wastegate will open fully once the max desired boost level is achieved, then close to almost 1/8" to continue to allow air to "bleed" through the hole. If it stays fully open, the boost level will drop off sharply.

One of my actuators should solve your problem.

 

[95eclipseSlow]

i dont want to push it over 25psi. im just going to have the 95 dollar arp head studs and im not sure how much boost they can take. maybe i will just shim it a little bit that should get me to 25psi.

 

[Calan]

i dont want to push it over 25psi. im just going to have the 95 dollar arp head studs and im not sure how much boost they can take. maybe i will just shim it a little bit that should get me to 25psi.

At 25psi, the E316G is at the edge of it's map...IAT's and knock will be much more of a problem than those ARP's.

 

[matthewdesigns]

As some have stated, try shimming it with 1/2/3 washers and see what happens. I've got 2 in mine and it holds 26+psi. Another thing that I played around with was the size of the bleed hole in my mbc-to-wga vac line. I ended up with one about 1.5mm in diameter for the best balance b/t spiking and holding.

Don't do it unless you can monitor timing or knock, and afr's. Higher than 26psi nets me very little extra airflow, but a lot more hot air, so unless you are on e85 or race gas, you could start doing bad things to your motor at that level.

 

[pboglio]

Sure can. I currently have two Holset actuators at the shop that can be used to turn OEM Mitsu actuator into one of mine.


This is happening because the actuator doesn't have enough spring tension to pull the flapper shut again once the airflow begins to pass through it.

A properly functioning wastegate will open fully once the max desired boost level is achieved, then close to almost 1/8" to continue to allow air to "bleed" through the hole. If it stays fully open, the boost level will drop off sharply.

One of my actuators should solve your problem.

We will definitely be having a conversation, I may need that stiffer internal gate.

 

[JayRolla]

Its crazy how running the extra boost on the 16g doesnt add much airflow but i sure does let the tq hit a lot harder. Car dont make much power but the low end tq hits so much harder with boost spiking at 32psi then just letting it run 26psi.

 

[matthewdesigns]

^^ Yep. I make way more TQ than HP thanks to this little quirk

 

[KFT0001]

My unmolested E316g held over 30psi without issue.

 

[JayRolla]

My unmolested E316g held over 30psi without issue.

I dont believe you. I can name over 20 16g applications that cant hold boost unmolested. You would be the first ever my friend.

 

[Calan]

My unmolested E316g held over 30psi without issue.

Spiked over 30? Maybe...

Held over 30? Would love to see that one. Got any pics of the turbo and a log?

 

[jrohner]

I could never hold over 22 psi on top, even if I had it at over 30 on the low end. I first put a big spring to pull on the wastegate flapper, and then I even modified a Holset WGA to fit my 16G, and that didn't help much either (2 extra psi). I have now switched to an Evo 8 ECU and use ECU controlled boost with a 3-port solenoid. It seems like I can now run any boost I want. I actually hit 30psi at 7 grand when I first was starting to tune the system (held a lot better than I thought it would).

 

[JayRolla]

I could never hold over 22 psi on top, even if I had it at over 30 on the low end. I first put a big spring to pull on the wastegate flapper, and then I even modified a Holset WGA to fit my 16G, and that didn't help much either (2 extra psi). I have now switched to an Evo 8 ECU and use ECU controlled boost with a 3-port solenoid. It seems like I can now run any boost I want. I actually hit 30psi at 7 grand when I first was starting to tune the system (held a lot better than I thought it would).

Wierd my brother runs Greddy's ecu controlled boost with solinoid with all the cool features. It did nothing to hold boost. Just helped with spool since he can actually tune the boost curve. I dont see how electronic boost control would help it hold more boost when its a mechanical issue.

 

[My1GLaser]

Should I be able to hold 28-30 psi to redline with an external WG? I have the 18g6sl2 which should be close enough to the 16g for this discussion.

I have tried literally everything and I still get horribly unstable boost. (Tial 38, hallman pro rx, restrictor in the dump tube, fp race mani, 2.5" tubular O2 housing) The boost needle flutters and my logged MAP is all over the place. 27, 25, 28, 26, 24, 25, 22...I am tired of this sh_t! Can't I just run a nice stable 28-30 psi on this thing to 7500 rpms???

 

[pboglio]

Should I be able to hold 28-30 psi to redline with an external WG? I have the 18g6sl2 which should be close enough to the 16g for this discussion.

I have tried literally everything and I still get horribly unstable boost. (Tial 38, hallman pro rx, restrictor in the dump tube, fp race mani, 2.5" tubular O2 housing) The boost needle flutters and my logged MAP is all over the place. 27, 25, 28, 26, 24, 25, 22...I am tired of this sh_t! Can't I just run a nice stable 28-30 psi on this thing to 7500 rpms???

30 psi at 7500 rpms would produce a massive amount of power, something your compressor couldn't support, hence the natural drop off of boost.

 

[JusMX141]

Should I be able to hold 28-30 psi to redline with an external WG? I have the 18g6sl2 which should be close enough to the 16g for this discussion.

There's only so much a small turbo can do when you're wringing it for all it's worth. You should expect to see 30psi drop a couple PSI by redline as the engine gobbles up airflow, but if you're seeing boost dropping 9psi like pboglio, it's definitely a wastegate issue.

 

[My1GLaser]

There's only so much a small turbo can do when you're wringing it for all it's worth. You should expect to see 30psi drop a couple PSI by redline as the engine gobbles up airflow, but if you're seeing boost dropping 9psi like pboglio, it's definitely a wastegate issue.

It holds 29 psi from 4k to 5k and drops to about 22-23 at redline. Maybe I will look into a stiffer WG spring? I guess at least a 1.5bar. I just bought the Hallman pro rx b/c I thought that maybe the Joe P wasn't reacting quick enough to keep a stable boost cause my logged boost flutters like hell. I will crank on the MBC a little more too, so at least I will hit 32 then taper off.

I guess my +1mm valves, ported head & 272s are making the issue worse...so its definitely time for a 7 blade HX 35.

30 psi at 7500 rpms would produce a massive amount of power, something your compressor couldn't support, hence the natural drop off of boost.

Yeah FP shouldn't have said that the new 18g6sl2 maintains its compressor efficiency in the 22-28 psi range. They should have said "it holds 28 for a thousand rpms then tapers to 22 just like the Evo 16g, but the new turbine wheel is a little laggier than you hoped for." I'll keep trying to make this thing pump out 28 psi til redline, until I get my HX-35. Sorry for the cynicism, but it comes naturally.

 

[JusMX141]

If you're cranking up the MBC and seeing the spike number increase but the holding number remains the same, your spring is too soft and you're right where someone with a weak internal actuator spring would be....the gate is staying open once the boost begins to pass through it.

You can only *safely* double a spring's recommended pressure using a MBC; this doesn't mean a 20psi spring will hold 40psi, either....the amount of pressure a spring can hold goes down as the boost level climbs. You should still try to keep the spring pressure somewhat close to your desired max boost level to prevent boost drop with any turbo.

 

[pboglio]

When I pulled 30 psi dropping to 22 psi, I was holding 44 lb/min flat as a pancake, and about 400 w.h.p. according to "Link". There might be some more boost left, maybe the wastegate and speed density will help.

 

[JusMX141]

Yeah FP shouldn't have said that the new 18g6sl2 maintains its compressor efficiency in the 22-28 psi range. They should have said "it holds 28 for a thousand rpms then tapers to 22 just like the Evo 16g, but the new turbine wheel is a little laggier than you hoped for." I'll keep trying to make this thing pump out 28 psi til redline, until I get my HX-35. Sorry for the cynicism, but it comes naturally.

That's mostly due to FP using the same Taiwan-built turbine housing that came on the GT Concepts Evo III 16G. This housing comes from the factory with a 34mm flapper installed, so there's really no hope for the turbo holding 30psi to redline.

 

[My1GLaser]

I just pulled apart the WG & I have the 1 bar spring, so the 29 max sounds right along with the horrible taper after that.

I will be ordering the small blue one tomorrow and maybe 23 psi of springs will get me to hold 28. Thanks guys.

I can't believe that big ass spring wont keep the boost stable...its only exhaust. I probably should have looked in the WG sooner to see what spring I had since I bought it used.

One last question then I will stop the hijack...I really hope this helps the OP too.

Shouldn't I be hitting full boost in 1st & 2nd with this little turbo? I can't understand why I am not. I hit 22-23 in 1st & 25-26 in 2nd. I only hit 29 in 3rd & 4th...