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5 hours ago, Dose Pipe Sutututu said:

Is there a chance your car is misfiring coming onto boost or timing is so retarded EGTs go through the roof? If so youll get a spike as you're describing.

I have no idea but

Could it be the tuner not being able to sort this problem out ?

Or the ECU not being able to handle it ?

10 hours ago, Kinkstaah said:

I have a 50mm gate with a Haltech 5 port solenoid, with a 12psi gate spring in it. (i.e, it'll hold 12psi when directly connected, boost control is off). I am running a PS2000 ECU.

I can sort of run this in Open loop mode, but again with only very very conservative settings, which amount to basically having the gate fully open (i.e running 12psi) and ever so slowly adding duty cycle to avoid overboosting.

Some of this may be my setup which is why I am asking, I have an EFR7670 (1.05 rear) on a RB28Neo - And I am only trying to run 6psi over the baseline boost, i.e 18psi. The duty required to do that is only about ~15-20% duty cycle. I would assume if I was trying to run 25psi or 30psi it would be 'easier' as the duty cycle wouldn't be going from FULL CLOSED (to aid spool) to 15% (almost fully open), it may be going from 100% to 70% duty cycle, or whatever duty cycle is required to run 25-30psi in that example.

Given this, I am only getting full boost about 3700rpm, which most people would assume is kind of 'laggy' for a 2.8 with a 7670. I don't really mind the lag so much, but I do mind the overboosting as it's not consistent and it's severe. 

Now, a lot of people in this thread are 450-500rwkw and running 25-30psi so this issue may not be this present, or it could be a 'problem' with these turbos or these setup. Just asking around to see if anyone's got some insight here!

What brand manifold? Is it possible its how the gate is positioned?

6 hours ago, Nismo 3.2ish said:

I have no idea but

Could it be the tuner not being able to sort this problem out ?

Or the ECU not being able to handle it ?

He has an auto, would not surprise me.if there are parts of the map that have timing pulled out where the gear changes happen.

I have a manual in the car now.


I have the timing map which is pretty conservative linked below. Johnny may find it familiar :P

It's pretty conservative, but it's similar to what most people run on 98, though the car is running E85. The issue still exists on 98, which is why I am running E85 lol. Perhaps it is in fact too conservative?

The gear changes only ever happened when I wanted them to happen when the auto was in anyhow, because it was fully manualized. I did initially put this down to the torque converter slipping and hyper spooling the thing. But it seems while the issue is lesser now, it still exists.

It's a 6boost T4 TS manifold, running one large gate.

I saw @HarrisRacing make a post on the Haltech forums about the same issue in a very similar car (i.e 2.8 with an EFR) saying that when he loaded up 4th gear (after a shift, coming back onto throttle) it would overboost and spike.

It may just be a thing with people trying to run lower boost on these turbos, (HarrisRacing seemed to be the only one other than me) and may not be an issue as most people tend to take aim at high 20's to 30psi.

Timing.JPG

Pretty noob with all this, but doesnt a 7670 on a 2.8 Neo seem like a very small turbo? Maybe its just too small and the 2.8 is pushing it hard and able to push boost right past what the gate should be limiting it to?

Someone I know is running a .92 7670 on his RB30 and is complaining about not spooling it soon enough but it never mentionned any overboosting or spikes when it reaches full boost (mid to late 3k).

 

What are the unit on your X axis on your timing map ?

If it holds 12psi without the boost controller in play, the hardware is probably ok (ie the manifold and gate setup).

Sounds like the boost control solenoid is either hooked up incorrectly, or the ECU settings aren't in the ballpark.  Whoever set it up, get onto them and have another go.

Sorry - That is MAP Pressure in PSI.

Mine is a 1.05, and tbh it does spool a lot slower than a SR20 with a EFR 7163 .85. Yes, its a smaller turbo but it's also a 2.0 and not a 2.8.

The 7670 is a 400-430kw turbo, I am only guesstimating that it's running in about the 360kw region at 18psi. It's not that small. Stabbing the throttle after being say half throttle does happen a fair bit, as that's pretty much right on trying to accelerate when doing about ~100-110 kmh.

To be honest I am sure 24psi or so at 4k isn't really going to harm anything, it's just something I noticed and wondered if it happened to other people who have delved into their own boost control.

 

 

3 minutes ago, Dale FZ1 said:

If it holds 12psi without the boost controller in play, the hardware is probably ok (ie the manifold and gate setup).

Sounds like the boost control solenoid is either hooked up incorrectly, or the ECU settings aren't in the ballpark.  Whoever set it up, get onto them and have another go.

It'll only hold 12 the boost controller fully off. (i.e gate pressure).

If I stab the throttle in the same manner, with it running like that, it'll 12" psi will spike to 18psi. With the controller off/bypassed entirely, piped compressor housing directly to wastegate etc.

If I do a pull from 2000, it'll spike a little. If I load it up (hill, whatever, and punch it/transition from 50% throttle to 100%) it will spike much much more, it's entirely reproducible actually.

The way to 'manage' it is actually to really make sure to really, really rev out every gear, or run much less boost than I wanted to. Neither of these are really optimal...

Given it happens with the controller off, I was thinking it's either setup related or turbo related. Hence me asking if anyone noticed any funny business with the EFR's super happy transient response-o-rama.

So effectively it does the same thing, whether the boost controller is activated or not?  Just that the boost levels (static, and rapid throttle change to spike) are higher?

Is this setup being operated in open or closed loop?

Possibly the gate setup/design has some deficiency, as per Roy's suggestion.

Got any decent pics to upload?

Yes, it does the same thing, but sharply opening the throttle, when the system is already under load/under boost makes it all happen much more severely.

Happens in open loop, closed loop and well directly connected. Open loop is 'easier' to manage because you can just hard set the duty cycle of the controller as opposed to using PID settings which are really hard to calculate when the boost is just doing whatever the fk it likes and won't behave consistently anyway.

It could be the gate setup, but it's a 6boost with a 50mm Turbosmart gate. There's nothing overly special about it.

Maybe this happens to everyone and I drive like a spastic.

I'd suspect the gate or it's plumbing, wether not moving fast enough or freely enough in it's guide and/or some plumbing/diaphragm leak.

The fact it is able to bypass enough gas to maintain a solid 12psi from down low means that it is big enough, not that it is functionning proprerly when it needs to move "fast".

 

I'm no expert in tuning but that map seems unnecesarily conservative especially on E85. My 20 is running 15° more degrees around the 14 psi range... on P98 and an other 5 to 7* on E85. I know that not apples to apples with my stock 20 internally gated vs your built 28 external gate but still.

Control your gate or swap it with an other known good one plumbed directly to the compressors housing and see if it change anything. If not then put some timing in. 

  • Like 2

Pressure/leak down test your lines to your wastegate.  Use an air compressor set to 12lb on the gate, disconnect the hose from the intake pipe and pump it up.

If you can do this with the manifold off, all the better as you can see the gate open.

I suspect either a leak in your wastegate line(s), boost control valve, or a hole in the wastegate diaphragm. 

 

 

Guess I'll have to do some investigating. I know for a fact the lines aren't fked or leaking because sadly they have been checked 500 times over the years, and I just checked them in the carpark just now...

Car is going on the dyno when I come back from overseas, so will actually post the result then. Keen to see what the difference between auto and manual truly is.

Note: I have a 5 port mac solenoid, with 2 vents, (IN, A, B, EXA, EXB), but from all accounts it appears to be plumbed up correctly.

Oddly enough, Fullrace sell a 4 port which I'm assuming functions the same, https://www.full-race.com/store/garrett-turbos/full-race-4-port-boost-control-solenoid-1/


However they list two different configurations for plumbing, one for EWG and the opposite for a Twin Port IWG setup, which I always thought effectively behaved like an external gate. Worst case I play with it on the dyno and see/replicate the spike and just enjoy more midrange :P

1 hour ago, Kinkstaah said:

 

Note: I have a 5 port mac solenoid, with 2 vents, (IN, A, B, EXA, EXB), but from all accounts it appears to be plumbed up correctly.

Oddly enough, Fullrace sell a 4 port which I'm assuming functions the same, https://www.full-race.com/store/garrett-turbos/full-race-4-port-boost-control-solenoid-1/

 

I've seen 3 and 4 port valves, but 5 is a new one to me.  Was there a tech or performance advantage to 5 port as the reason for choosing one?

If it's a Haltech product, I can't see anything on their site (or anywhere else online with a 1 minute search) for how a 5 port valve plumbing is configured.

Maybe get onto them for tech help to at least confirm.

Some pics on the WG placement and pipe angles would  be a big help for people to understand what's the problem.  Bench testing the gate for correct function and all intact would also be a good idea.

Pretty sure most of us are guilty of failing to review/check ALL the basics when something doesn't seem to work as it should.

  • Haha 1
On 14/10/2017 at 11:57 PM, Kinkstaah said:

I have a 50mm gate with a Haltech 5 port solenoid, with a 12psi gate spring in it. (i.e, it'll hold 12psi when directly connected, boost control is off). I am running a PS2000 ECU.

I can sort of run this in Open loop mode, but again with only very very conservative settings, which amount to basically having the gate fully open (i.e running 12psi) and ever so slowly adding duty cycle to avoid overboosting.

Some of this may be my setup which is why I am asking, I have an EFR7670 (1.05 rear) on a RB28Neo - And I am only trying to run 6psi over the baseline boost, i.e 18psi. The duty required to do that is only about ~15-20% duty cycle. I would assume if I was trying to run 25psi or 30psi it would be 'easier' as the duty cycle wouldn't be going from FULL CLOSED (to aid spool) to 15% (almost fully open), it may be going from 100% to 70% duty cycle, or whatever duty cycle is required to run 25-30psi in that example.

Given this, I am only getting full boost about 3700rpm, which most people would assume is kind of 'laggy' for a 2.8 with a 7670. I don't really mind the lag so much, but I do mind the overboosting as it's not consistent and it's severe. 

Now, a lot of people in this thread are 450-500rwkw and running 25-30psi so this issue may not be this present, or it could be a 'problem' with these turbos or these setup. Just asking around to see if anyone's got some insight here!

Can you give as much detail as possible about what you've done, or link to a post to it?


Ie, what brand exhaust manifold?  What exhaust setup?  How does the wastegate dump merge with the rest of the exhaust (if it does) What intercooler?  Do you have pics of any of these things?    What blow off valve?

You have definitely tried this with the open loop boost control turned OFF completely?   The stickler in me feels that so long as there is any electronic boost control influence involved, it could be to blame - not saying that I believe that's what it is, but it should be ruled out.

Something that sticks out to me is I understand there are possibly two issues,

1) It seems laggier than expected

2) It boost spikes

Some of the most common causes of #1:

- Boost leak
- Poorly performing exhaust (pre or post turbo)
- Pre-turbo exhaust leak

Some of the most common causes of #2:

- Boost leak
- Poorly performing exhaust 
- Waste-gate problem
- Tuning (particularly where electronic boost control is involved)

I don't have heaps of time to do more than just spit out the first things that come to mind, but it's hard to ignore that you have 2 weird issues which have 1 or 2 common causes - quite a coincidence.

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