problem controlling boost
 

Ok so i have built yet another motor. Mods list

Manley Rods
Wiesco Pistons 9.5:1
CPE manifold
Tial 44 gate (14psi spring)
5/6 port (currently not installed) soon
full exhaust no cat
porting intake
3.5 intake
AP
Tr10 intercooler

ok so here is my probem.

Broken in the motor and went into boost to see how the car felt. Boost rises to about 30+ psi.... WTH.... i saw it backed out. check the gate to make sure diaphram wasnt sicking went out again and boosted it again 30+ before i let off.... Change the gate to another known gate and boost still hit 30+ psi..... So we then bypassed the boost solenoid and ran a hose straight to the wastegate to eliminate the solenoid being the problem still boost to 30+ psi. With all these test and this high of boost we could never hear the wastegate open.
Check the pressure from the compressor to the wastegate was fine.


So we took it to the far extreme and took the gate completely off the car and we were still able to make 11 psi on with not gate on the manifold and nothing blocking the manifold.... WTH...

Any suggestions..

Sounds like there is a casting problem in the manifold.. I'd look for an obstruction where the wastegate takeoff meets the collector.

I will take the gate off tonight and look in there.. i figured due to size of runners i wouldnt have to worry about this but i will investigate more tomorrow...thx

I don't think you'll find a defect in the manifold.
Getting to 11 psi boost with the wastegate completely off is possible. The branch for the WG on the CPE mani is perpendicular to the gas flow from the runners so the turbine will get a good amount of air due to the inertia of the mass flow spinning the turbine alone even with the wastegate off.

I'd just run the lightest possible spring you can find for the 44mm WG and take it from there. Using a 14 psi spring doesn't always mean you'll get 14 psi boost irrespective of other aspects of the construction.

wow i'm surprise an ewg generate so much creep. Between uncontrolled 30+psi and 11 psi, you could probably find a spring to creep in between ?


What is the turbo ?

Being able to run 11psi with a gaping hole in your manifold tells me you don't have much exhaust pressure in your manifold and/OR, as stated above, exhaust flow favors the turbine housing by design or obstruction and will shoot right on past the WG port.

Exhaust pressure and boost pressure work together to push the WG open. Which is why EWG have the port on the tophat too. Applying boost pressure to the tophat ensures the WG stays closed no matter how much exhaust pressure you have (even with a very weak spring) and it will only open when the EBCS tells it to.

So you could try a very weak spring and switch to a 4-port setup and see what happens.

This was the very thing my buddy and i was talking about last night!!! I will be working on the car again tomorrow after work. So i will swap out the springs then. My question is as you are turning up the boost and if it is flowing so well like that then how bad will it be at higher boost levels to control.

The turbo is a 5858... also i think this this is not the correct definition of "CREEP"

I agree, if the gate isn't opening it cannot be called creep.

I'm curious to know how it goes and if you can find a spring to come closer to your boost goal.

So with my 14 psi spring i was creeping to 21 at rl with the 5858jb with the ported s cover FWIW.

Have you tried to run the gate with no hose?

How are the hoses ran? When i did my first pull i messed up the routing of the hoses and hit 30psi just like you. Fixed them and i was good to go.

You can pressure test it just to confirm connections and spring choice with a portable tank or compressor and a regulator. A boost gage connected with a T to get a more accurate reading and figure out at which boost pressure the gate is really fully open.
This would quickly point out plumbing or spring problems.
There is many ways to plumb it but personally, i would keep it simple to make it work first.
https://www.onpointdyno.com/boost-co...ht-save-money/

It should not be a problem to control boost with that 44mm WG. I am also running a CPE mani with a 44 and boost control is cake. I get very stable boost control all the way from 18 psi to 30 psi. None of that overshooting shit with the small penis IWG I used to get. It's all failry straight forward once you have the correct spring in there for your target and everything plumbed correctly. The WGDC compensation tables can all be reduced compared to what you'd run on a IWG.

http://i1211.photobucket.com/albums/...psc1fsqmmp.jpg


http://i1211.photobucket.com/albums/...psqqivsmej.jpg

What manifold do you have? If not a cpe manifold this might be a irrelevant conversation sorta. Creep comes from the inability to slow the exhaust flow to the turbine wheel down hence wastegates job..

As for the routing of my hoses.... when it first happened i decided to do process of elimination, the boost source my be clogged, so i pulled the nipple off and look in there. That turned out to be fine. Replaced the nipple. Routing was nipple to #3 port on EBCS and then from there #1 to the side of the wastegate. Didnt work, so for shits and giggles i put it on the top port didnt work...Then i ran a hose from the compressor housing to the bottom of the wastegate to eliminate the EBCS as the problem Didnt work....then to make sure i am getting pressure from the compressor to the wategate i put a manual boost gauge in between the comepressor and wastegate.. Got the 30+ i was seeing on my AP...

Connected the manual boost gauge to the bypass vacuum source still got 30+ psi... Had another wastegate from my car( remember this is a customers car that i am having a problem with) Also rememebr i too have a CPE manifold with a gt35r on it currently with no issues. Installed that gate because i thought maybe i in stall the spring in the customers gate wrong or maybe i pinched the diaphram during install of the cap. STILL HITTING 30+ psi


Now we are the no wastegate test:

Was testing if we got boost then that either does one or two things. Leads to a manifold defect or what the other guy was saying about air flowing past the wastegate hole.

If very low 1-3 psi or no boost then its a wastegate issue.

Results 13 psi with no gate on there... and now we are here.....got it

I agree with a size hole that you should be struggling to make that kinda boost with NO GATE on the car. MY CPE manifold is tits on with my boost i desire..

I have a cpe manifold with a precision vband and tial 44mm wastegate.

I have port 2 on my GS to the bottom port of my tial, port 3 to the compressor housing and port 1 vta.
The top of the wastegate is vta.

I would take the wastegate apart and see if something is jammed up inside. Push on the valve and make sure it actuates. Spring pressure shouldnt be 30psi unless the gate isnt opening because it is binding.

Thank you for your comment but i addressed this in the first post...."changed the gate to a known working gate"...

Hate to bring this back but... I'm having the EXACT same problem. Did you find any resolution to this? I have gone through all of the tests you did including removing the wastegate COMPLETELY from the manifold and I'm actually getting 16psi by 6500rpms.... through just a giant hole in the manifold LOL!

CPE turbo manifold with PTE Vband entry 5862.

With wastegate on and 5psi spring I max out fueling by 6k rpms at 25psi having to let off

With NO SPRING in the wastegate I still hit 24psi by 6500rpms

With NO WASTEGATE on the manifold I hit 16psi by 6500rpms and it was still climbing

I've been going back and forth with CPE's head engineer and he of course keeps telling me this isn't possible and that it's my wastegate. I sent him the logs without having a wastegate on the car, but haven't heard back yet.

I'm hoping it's a casting defect or something, but I have another manifold lined up to swap out. I've been fighting this for months and now at least people can't say I'm losing my mind lol!

It is very strange that Tomas get good results while you aren't, can you see anything in the casting that could restrict the path to wg ?
I'm curious to hear about CPE feedbacks...

What do you mean by good results? We aren't saying we can't make power or do you mean he is able to keep boost under 20 psi to redline?

I've recently tracked down as many cpe/ 5862 combo running speed people as possible and almost all but one have told me they have enough boost creep that they can't have a di only tune.. Basically the lowest boost told to me besides the one guy claiming 14 psi to redline was 26psi by 6200. I'm sure if he revved higher that would keep climbing. Some might say who cares just turn it up, but there's other things this hinders. What if you have a PI or meth issue and your fail safe can't drop boost? I digress... Regardless when I had my manifold off i didn't notice anything out of the ordinary but I also didn't engineer it so who knows. I'm still waiting on a response from CPE. In the mean time I have no choice but to just roll with it and hit 30+ psi.

Just hoping op maybe made some headway on the issue as I'm at a total loss now lol.

I'll report back with what the engineer says about my logs and new info on the issue.

I was reffering to few post above yours where Tomas say it work fine from 18-30psi but i have no clue about the details...

Oh sorry. He's not on the same flange or turbo. People with 5858 don't seem to be having this issue as often except for OP so really who knows at this point. Crazy as it may seem the issue, as far as I have found so far is mainly with the 5862 vband entry.

Or better yet... CPE manifold w/ PTE vband entry in general I guess, but CPE still claims this has never happened.

ok and probably that any change to route more flow into the WG will reduce flow efficiency into the turbine....This also tell that your 5862 is easy to spin...

I get your point about fail safe systeme but even if it isn't the solution, you can still install a boost fuse. Instead of bypassing turbine flow, you can exaust/recirculate boost by the BPV. the Stratified GA do this or make your own with an EBCS connected to the BPV vaccuum port. When triggered, the solenoid valve let any pressure to escape from the BPV head to let it open under boost. If you hear the BPV opening under boost you will know something is wrong and probably lift off the pedal as a reflex...You can even trigger it by overboost too.

Very true that's a good idea. My original goal was to have a low boost daily DI only 93 octane map and then my PI all out war map for whenever lol. I had the chance to buy a nice customer tubular manifold recently that may have alleviated this issue for me, BUT one of the reasons (as you're saying) this can be happening is because this damn turbo just wants to flow and spin. CPE manifold is absolutely proven for POWER so I don't want to leave it, but something is definitely up here with this overboosting and it's not just a single isolated event.

Hopefully the engineer will get back with me, he's usually pretty quick to respond or if OP found what was going on that would be awesome too! :)

I have a custom DP, CPE mani with 6062 turbo and Precision 46mm ewg on a 15psi psi spring, it seems to start at 18psi after spool slowly goes to 19 at 5500rpm and stays at that until 7000rpm on a base map.
I did just receive a map targeting 22psi but something in my clutch area that sounds like a lunched throw out bearing has made it un driveable until we can get the gear box out and see what's going on FML

Will be interesting to see what the actual cause of the guys going to well over 20psi, that's a massive over shoot.

Very nice setup! You're wg is plumbed back in to DP and you're not creeping like hell. It's such a hit or miss situation :(

If mine would just stay at or below 20 I'd do a fucking cartwheel lol.. Hopefully Monday CPE will respond to my logs and all. We'll see what they say.

Zac

Just out of curiosity, have you changed to a higher reading MAP sensor and had it calibrated in the tune to read correct boost.

@Fah-Q; - Did you happen to shine a torch into the wastegate entry pipe from the manifold to check the casting where the five pipes join?

it's a 3 bar that is scaled properly, I thought of that as well at first. My 120+ idc backs up that I'm definitely hitting some serious boost lol.

When I first got the manifold and was looking in to the collector area and where the wastegate meets up everything looked normal. Basically nothing looked like it was a bad cast or anything crazy but I also wasn't specifically looking for this issue either at the time.

I offered to take the manifold off and bring it down the CPE to look at since they're really only a an hour or so away from me now and they basically told me to eat a dick lol.

They told me to weld a wastegate to my turbine housing :laughing:

Essentially they "check every manifold before it's shipped and there's no possible way our manifold is causing the creep, you need to go with a bigger turbine housing or weld a wastegate to the one on there"...

I've had a lot of people send me logs, some with and without creep. The ones without boost creep I noticed the throttle plate was closing considerably. I brought this up to CPE and they were like "oh that's a great idea"

So either way, guess it's just band aid and move on LOL

Are you speaking of hybrid or load based tunes that are controlling the throttle via calculated load tables?
You'd think one could rely on the wastegate to be able to control boost without resorting to that hey? :shrug:

Using throttle to control boost is a bandaid for a bad manifold design or possibly poor quality control of the product.

Thank you! Exactly

You'd hope you could rely on the wastegate / manifold properly pushing flow to it. Hybrid tune is what I've had to settle on right now to get throttle to basically almost close up top to hold any reasonable boost. It's ok though, just going to turn on the PI and send it :(