Wastegate Help!

[JayJay777]

Hey everyone, been having a bit of a boost drop on the C34, it was getting its caster rods done the other day and i asked the guy who was doing it and he said the wastegate had a lot of play in it? do i know what that means... not really. but i was wondering what wastegates people here run? stock? aftermarket? just kind of want to see my options.

to answer some questions which may be asked

its a non neo motor

currently does have a stock wastegate

i do want to go for more power in the future

thanks in advance who replies and tries to help out

[Murray_Calavera]

So you have the stock rb25 turbo?

So I'm guessing what the guy was trying to tell you is the wastegate doesn't have enough preload on it. Have a look at this video to see what I'm talking about. 

When you say you've got issues with the boost dropping off, how much boost are you running and how low does it get in the top end?

As for what I'm using, I use a Turbosmart IWG75 on a Hypergear turbo. 

 

[joshuaho96]

If actuator preload doesn't fix your problem it's possible that there is excessive wastegate bushing wear which will require pulling the turbos to fix. Not sure if that's a common issue with these cars though, it's mostly notorious in the BMW N54 turbos for whatever reason.

[JayJay777]

15 hours ago, Murray_Calavera said:

So you have the stock rb25 turbo?

So I'm guessing what the guy was trying to tell you is the wastegate doesn't have enough preload on it. Have a look at this video to see what I'm talking about. 

When you say you've got issues with the boost dropping off, how much boost are you running and how low does it get in the top end?

As for what I'm using, I use a Turbosmart IWG75 on a Hypergear turbo. 

 

yeah stock turbo.. i think?

well when i first got the car it was pretty sluggish and felt like a boat, i did a few thing like cleaning the maf and tightening some hoses and it went up to about 8 pounds of boost, which im pretty sure is still low even from factory but do correct me if im wrong, but now its gone back down to 5 pounds of boost.

with the wastegate did you have to modify it at all? cause ive seen a lot of the stock wastegates have rods with bends in them whereas the only turbo smart ones i can see at first glance have straight ones.

 

[Murray_Calavera]

25 minutes ago, JayJay777 said:

yeah stock turbo.. i think?

well when i first got the car it was pretty sluggish and felt like a boat, i did a few thing like cleaning the maf and tightening some hoses and it went up to about 8 pounds of boost, which im pretty sure is still low even from factory but do correct me if im wrong, but now its gone back down to 5 pounds of boost.

with the wastegate did you have to modify it at all? cause ive seen a lot of the stock wastegates have rods with bends in them whereas the only turbo smart ones i can see at first glance have straight ones.

 

Sounds like there is some shenanigans going on with the boost control solenoid. The wastegate spring is 5psi and the factory boost control solenoid takes it up to 7psi when over 4500rpm.

I would be very surprised if the play in the wastegate was causing these issues. Not enough preload on the wastegate generally just means a bit more lag and doesn't impact on the overall boost level.

The universal kit comes with a straight rod, vehicle specific kits will come with a bent rod if required. Have a look at the IWG75 kits to suit an evo for an example. 

My wastegate isn't on the stock turbo though, so my setup won't be the same as yours. I'm using the straight actuator rod, but if you need a kink in the rod for your setup, this can be solved in about 5 seconds with a vice and a hammer. 

Having said that, I don't think there is much value in putting this wastegate on the stock turbo. If the wastegate failed, you'd just replace it with another stock one. The reason for running the Turbosmart wastegate is to have more control over the boost levels, but with the stock turbo you'd never run it over about 10psi anyway and the stock wastegate will allow you to run that very easily with a boost controller. 

[JayJay777]

7 minutes ago, Murray_Calavera said:

Sounds like there is some shenanigans going on with the boost control solenoid. The wastegate spring is 5psi and the factory boost control solenoid takes it up to 7psi when over 4500rpm.

I would be very surprised if the play in the wastegate was causing these issues. Not enough preload on the wastegate generally just means a bit more lag and doesn't impact on the overall boost level.

The universal kit comes with a straight rod, vehicle specific kits will come with a bent rod if required. Have a look at the IWG75 kits to suit an evo for an example. 

My wastegate isn't on the stock turbo though, so my setup won't be the same as yours. I'm using the straight actuator rod, but if you need a kink in the rod for your setup, this can be solved in about 5 seconds with a vice and a hammer. 

Having said that, I don't think there is much value in putting this wastegate on the stock turbo. If the wastegate failed, you'd just replace it with another stock one. The reason for running the Turbosmart wastegate is to have more control over the boost levels, but with the stock turbo you'd never run it over about 10psi anyway and the stock wastegate will allow you to run that very easily with a boost controller. 

ah okay, this is why i need you rb geniuses to help me out haha, im very new to the engine and have spent the last 4 years working with EJ's so i feel very out of my depth here haha.

im just going of what ive been told by the mechanic ive gone to, hes been really trustworthy and has always shown me whats wrong before recommending i replace something, so perhaps ive misunderstood him.

i saw someone how did say that you could bend the rod but youd be missing about 10mm worth of length which is required, how true this is? not sure, again just what ive heard.

as on the topic of oem or aftermarket, i was thinking id just get aftermarket now as i do intend to put a high flow turbo on it at some point down the track and though i may as well get the better wastegate now rather than later, thoughts?

[Murray_Calavera]

7 minutes ago, JayJay777 said:

ah okay, this is why i need you rb geniuses to help me out haha, im very new to the engine and have spent the last 4 years working with EJ's so i feel very out of my depth here haha.

im just going of what ive been told by the mechanic ive gone to, hes been really trustworthy and has always shown me whats wrong before recommending i replace something, so perhaps ive misunderstood him.

i saw someone how did say that you could bend the rod but youd be missing about 10mm worth of length which is required, how true this is? not sure, again just what ive heard.

as on the topic of oem or aftermarket, i was thinking id just get aftermarket now as i do intend to put a high flow turbo on it at some point down the track and though i may as well get the better wastegate now rather than later, thoughts?

We are talking about fitting an aftermarket part, you do what is needed to make it work. If the rod needs a bend, bend it. If it's the wrong length, get the correct length rod. If you don't want to do any of this, pay for a kit that is bolt on - https://gcg.com.au/actuator-assembly-nissan-rb20det-rb25det-billet-dual-port-xtrwga-bdp-rb25.html

Obviously though that kit is for the stock turbo, you change the turbo you'll need to change the wastegate setup to suit the new turbo. 

As for what wastegate you should get, the only real reason for getting the Turbosmart wastegate is to be able to change your base spring pressure. There is a very strong chance you'll never need to do that. 

Lets say you buy a Hypergear high flow turbo and you want to run about 18psi. You can tick the box for the higher pressure actuator and that's it. You don't even need a boost controller and you have your 18psi. 

Say you want some adjustment. You buy the same Hypergear high flow turbo, but this time you get a 14.7psi wastegate spring. With a 3 port MAC valve you could theoretically take the boost up to about 30psi with that setup. Not happy with that range of adjustment? You could get a 7psi wastegate spring, use a 4 port MAC valve and take the boost up to about 30psi. So now you can run anything between 7psi and 30psi without changing your wastegate spring. 

My advice is if you don't know why you want to change the wastegate base spring pressure, don't buy the expensive Turbosmart wastegate. Have a think about what the min and max boost levels you would like to run, then buy a wastegate/spring/MAC valve that supports that goal. 

If I had a crystal ball, I'd probably see you buying a Hypergear turbo, using their high pressure actuator, using an aftermarket ECU and a 3 port MAC valve for boost control. 

[JayJay777]

42 minutes ago, Murray_Calavera said:

We are talking about fitting an aftermarket part, you do what is needed to make it work. If the rod needs a bend, bend it. If it's the wrong length, get the correct length rod. If you don't want to do any of this, pay for a kit that is bolt on - https://gcg.com.au/actuator-assembly-nissan-rb20det-rb25det-billet-dual-port-xtrwga-bdp-rb25.html

Obviously though that kit is for the stock turbo, you change the turbo you'll need to change the wastegate setup to suit the new turbo. 

As for what wastegate you should get, the only real reason for getting the Turbosmart wastegate is to be able to change your base spring pressure. There is a very strong chance you'll never need to do that. 

Lets say you buy a Hypergear high flow turbo and you want to run about 18psi. You can tick the box for the higher pressure actuator and that's it. You don't even need a boost controller and you have your 18psi. 

Say you want some adjustment. You buy the same Hypergear high flow turbo, but this time you get a 14.7psi wastegate spring. With a 3 port MAC valve you could theoretically take the boost up to about 30psi with that setup. Not happy with that range of adjustment? You could get a 7psi wastegate spring, use a 4 port MAC valve and take the boost up to about 30psi. So now you can run anything between 7psi and 30psi without changing your wastegate spring. 

My advice is if you don't know why you want to change the wastegate base spring pressure, don't buy the expensive Turbosmart wastegate. Have a think about what the min and max boost levels you would like to run, then buy a wastegate/spring/MAC valve that supports that goal. 

If I had a crystal ball, I'd probably see you buying a Hypergear turbo, using their high pressure actuator, using an aftermarket ECU and a 3 port MAC valve for boost control. 

okay first of all.. youre right, cant even deny on that. but yeah i get it now and its all kind of clicking into place now, thank you. is the high flow something youd actually recommend or do you think that maybe a different turbo might be the way to go? always looking for more opinions on what direction i should go with my build.

 

[Murray_Calavera]

7 minutes ago, JayJay777 said:

okay first of all.. youre right, cant even deny on that. but yeah i get it now and its all kind of clicking into place now, thank you. is the high flow something youd actually recommend or do you think that maybe a different turbo might be the way to go? always looking for more opinions on what direction i should go with my build.

 

That is a super open question, really comes down to your goals and budget. 

It's very easy to say buy an Artec manifold and a Garrett G series turbo, but unless your happy to spend about $6,000 on those 2 parts alone, well your not going to get very far lol. 

Maybe have a look at RB25 turbo results thread for inspiration. 

[Dasmbo]

Hi i wouldnt wast my time trying to get more boost out of your stock turbo because if the inlet wheel disintergrates into a few hundred peices and exits the manifold into the engine causing lots of internal damage not to mention the shock to your wallet.With something like an Hypergear turbo which are not to expensive you wont have to worry about a stock turbo disintergrating and destroying your engine. I have been using a Hypergear turbo on my setup for the past 10 years with no problems and consistantly makes good power. 

[GTSBoy]

1 hour ago, Dasmbo said:

Hi i wouldnt wast my time trying to get more boost out of your stock turbo because if the inlet exhaust wheel disintergrates into a few hundred peices and exits the manifold into the engine causing lots of internal damage not to mention the shock to your wallet

Fixed your post a bit. Decreased the size of the incorrect info, because there is no strikethrough format available in the post editor.

The ceramic turbine breaks, not the compressor wheel. And the turbine fragments very seldom have caused engine damage on a single turbo RB. The damage you speak of is pretty strictly an RB26 problem. This is because the 26 exhaust manifolds allow a short and straight shot at the exhaust ports. The single turbo manifolds just don't do that.