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External Waste-gate Question.


Tricky-Ricky

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Having fitted my single, and aside from all the smoking issues, i have been trying to set up my Blitz I-colour boost controller, now i have run this with my twins for a year or more, and although i needed to use both high set and gain to achieve the boost and spool i wanted, it functioned OK.

But with the single and external WG i seem to have slow spool, at least slow to what most people say about the GT4088?

the gain is OK and i am using a set value of 25 to achieve 0.9 bar of boost, i have the gain set to 75 and still have slow spool, it has made a difference adjusting it but I'm wondering how far I'll have to go, from my quick test the WG seems to have a 0-5 bar spring, has anyone a suggestion ?

Edited by Tricky-Ricky (see edit history)
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Set the wastegate a little higher, 1 bar? Either that or get a hold of an MBC, set your boost controller to around halfway then set the MBC so that you are reaching around 0.8 bar. Once its doing that, adjust the electronic boost controller to get the boost required.

 

Of course that would only be a temp solution as something is wrong somewhere.

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Its an XS 50mm one i think, but as i said i rebuilt it cleaned and greased the shaft so there is no reason for it to stick, the only thing i can think of is that the spring is maybe to weak to hold it, but i don't really want to go up to a 1.0 bar spring as i want to be able to run 0.8-0.9 bar.

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MBC - Manual Boost Controller (i woudlnt bother if you have the blitz EBC)

 

Neither would i... if it was working correctly. I'm suggesting to use a manual boost controller as the EBC is at its highest setting. The MBC will allow more adjustment ;)

 

Its an XS 50mm one i think, but as i said i rebuilt it cleaned and greased the shaft so there is no reason for it to stick, the only thing i can think of is that the spring is maybe to weak to hold it, but i don't really want to go up to a 1.0 bar spring as i want to be able to run 0.8-0.9 bar.

 

Ahh, i thought you would have been going for 1.2ish. I would give the MBC approach a try. Its not a solution, only a means to weed out the problem.

 

Its strange that you needed to have the EBC on max with your twins too. I don't really understand how they work but surely if i was to add a boost controller to my system (currently running 1 bar at its own free will) a 0 setting would give me 1 bar and a +25 setting would give me a lot more?

 

Sounds very iffy, if the MBC gives you more boost then that points to the EBC......... i think.

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Yes its always been a bit weird, i need a set value of 60 to get the twins to 1.1 and that was with a shimmed actuator, and then it still needed gain set to similar to get a good response, wonder if its because i use the plenum as a reference source?

anyway at the current setting it appears that the boost set value is about right if the WG spring is 0.5 bar and i have dialled in 25 to get 0-9 bar, its just the gain at 75 it should be building boost earlier?

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If you heat grease up to about 700 degrees C it will go to a black sticky goo, or even solidify. May be worth stripping it and DE greasing it :)

 

Good point, but it has behaved like this from the first run, so i doubt it was sticking then, also i used copperslip which usually puts up with high temps? however i will take a look:)

Just remembered that i am still running a 2.5" second decat pipe, would that have much of an impact on spool up?

Also i haven't seen more than 600c from the exhaust housing yet.

Edited by Tricky-Ricky (see edit history)
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Quote:

i need a set value of 60 to get the twins to 1.1

 

What is the set value of 60? What units is that?

 

Ramping up the gain(assuming its the proportional) doesnt always guarantee response, it can oscillate

 

 

__________________

GT35R controlled by MoTeC M600 coming soon....

 

 

I presume the set value is relating to %, not seen any signs of spiking/oscillation in my datalogs.

Edited by Tricky-Ricky
DP (see edit history)
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Greasing the wastegate shaft wont make it better as like Chris said, it can go hard when burnt and set onto the shaft.

 

I know from past experience that these wastegates always stick. The shaft needs to be sanded down because it heats up quicker than the wastegate hole and expands - hence why it sticks. I had to do this on two wastegates and was experiencing similar problems to you so i would suggest doing this and seeing what effect it had.

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Have you changed the type of wastegate on the settings from internal to external?

 

You need to go to the 'function' setting, then AC/WG, on the stock twins you should have had it set to AC, on the single with external wastegate you need it set to WG.

 

If you need an English copy of the instructions drop an email.

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I still think there is something wrong with your setup. Even your initial setup seems a bit iffy. Did you try the twins without a boost controller? What were you getting?

 

The reason i ask is, as i have already said, i get 1 bar with a double de-cat, exhaust and a restrictor ring in place. If i was to add a boost controller i wouldn't need to do anything to get 1 bar as there is no way of creating negative gain with a boost controller so i would only need to increase the gain to increase the boost. From what i gather, you were only getting around 0.8bar until you started upping the boost with the controller.

 

Basically what caused your car to only boost to 0.8bar?

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My twins where UK hybrids, so needed a boost controller to get any boost out of them, and don't forget that i ran them in TTC so the actuator was dealing with controlling boost for parallel setup, also as i said i needed to shim the actuator to get desired boost with the controller, its common practise on 200sx as actuators can get weak over time.

The issue here is not the boost target, its the speed that its reached that is not right.

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The wastegate could quite easily be stuck open at the equivalent to 0.8-0.9bar of boost (whatever that stroke on the valve is).

 

That will seriously balls up your spool time and yet still keep you limited to that boost.

 

As a risky test you could remove the vac/boost feed to the wastegate completely and see if it still spools slow. If it does then it isn't the BC and also if it limits you to the same 0.8-0.9 bar then you know it's stuck open....be careful though!!

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