No boost under load.

[tcavenger99]

I am using an IHI RHB5 turbo on a 420A with a side mount intercooler and a 3000GT BOV. I have installed Wiseco 8.1:1 pistons and Eagle rods on an automatic tranny. Here is my problem: the boost gauge at idle reads 15 vac, upon acceleration it goes to zero and pushes sometimes 4 psi, but it fluctuates from 1 to 5. It doesn't seem like the boost is there, plus after a little driving the pressure backs off and eventually there is no boost at all. Now for the funny part; if you come to a stop hold the break and press the gas the boost climbs to 10psi all the time. I am using the wastegate that came with the turbo which happens to be an external wastegate. Any thoughts?

 

[1slow97]

Have you check the car for boost leaks?

 

[totaleclipse_05]

What are you using for a fuel system? 10 psi on a basic FMU setup is a big no-no.

 

[TalonESIT]

From what it sounds like you may have an issue with that wastegate. I would say check for leaks as well, but your saying when you boost it holds at about 4 and then fluctuates correct? If there was a leak then it would keep trying to go to zero when accelerating. Are you sure it is fluctuating? Or does it look like it is trying to build boost but dropping? What is your wastegate spring set for? Did you just throw it on or did you open it up and check on it? When you accelerate from a stop an it builds to 10psi does it taper off back to 4 or does it hold at 10?

If you answer some of our questions we could help you more, like total eclipse said you do not want to run 10lbs of boost on a stock fuel system, and even if your running on a basic fmu your disk ratio may be applying too fuel pressure, but this is irrelevant to your question so we'll deal with your boost issue first.

 

[tcavenger99]

sorry about grammer i am using a walbro fuel pump on stock injectors with a fmu. ok i solved my no boost problem hole in innercooler dumb me , i by passes it so turbo is stight to intake . now i it hits 6 psi ,on high ref it hits 10 . on that same note it seems like the car pulls but the gauge stays at the top boost.. example say i floor it the boost hits 6 psi and stayes there then it solowly eases back. the wastgate is free not stuck .. how can i check it without running after the car and looking under the hood

 

[totaleclipse_05]

Do not run more than 4 psi without an intercooler.

Sell your car before you blow it up.

 

[TalonESIT]

Do not run more than 4 psi without an intercooler.

Sell your car before you blow it up.

Anyways, tcavenger99 your english is extremely hard to follow, but I'm guessing what your saying is that you boost to 6lbs and it slowly drops. If your wastegate is a cheap one it's probably not working correctly, and on a side note totaleclipse is right again, I would not boost or drive around with no intercooler. I understand in this case you probably only did it for a bit just to test if you found your problem, but don't do it for long periods of time or a rebuild is right around the corner for you; and what do you mean that the wastegate is free and not stuck? Your boost is spiking which means something isn't holding in that wastegate. A leak would not spike settle then drop, it would more than likely just constantly drop. But you could still have a leak as well as your wastegate issue. To check for boost leaks you have to have some kind of boost leak tester, go to www.VFAQ.com and click on the dsm link then go to turbos and there should be a nice write up on how to make one. It does seem like you also have a spike problem associated with that leak or the whole issue could be due to that wastegate. Go over your pipes again make sure your clamps are tight and your BOV is not leaking either. When you say "it eases back is it because your pulling off of the gas?" elaborate.

 

[dsmdragon]

Do not run more than 4 psi without an intercooler.

Sell your car before you blow it up.

He has an intercooler...... He said that. also just last post he said the problem was the intercooler.

Anyways, The problem sounds like the wastegate, but runs like it's half-ways workin. You might need to take it off and see if the flaper moves.

 

[silver bullit]

What are you using for a fuel system? 10 psi on a basic FMU setup is a big no-no.

Well are you using only this?


Also type in other mods you have done, everything.

 

[Slippi84]

For a heads up they are going to REAM you for your grammar, ! Back to the topic though, from what it sounds like you may have an issue with that wastegate. I would say check for leaks as well, but your saying when you boost it holds at about 4 and then fluctuates correct? If there was a leak then it would keep trying to go to zero when accelerating. Are you sure it is fluctuating? Or does it look like it is trying to build boost but dropping? What is your wastegate spring set for? Did you just throw it on or did you open it up and check on it? When you accelerate from a stop an it builds to 10psi does it taper off back to 4 or does it hold at 10?

If you answer some of our questions we could help you more, like total eclipse said you do not want to run 10lbs of boost on a stock fuel system, and even if your running on a basic fmu your disk ratio may be applying too fuel pressure, but this is irrelevant to your question so we'll deal with your boost issue first.

He's from canada so go play english teacher somewhere else. Nothing worse than guys who get kicks acting like car gurus by saying well you spelled this wrong

Anyway you don't set a wastgate spring. A springs tension set's it's boost rate as a spring that takes 7psi to compress and open the wastegate is a 7psi spring. Automatics buildboost by brake boosting because they actually put a load on the turbo and that's why you can buid boost at a stop but seems like it dros off or runs inconsistantly during regular driving. Ge a boost leak tester and then go from there.

 

[TalonESIT]

He's from canada so go play english teacher somewhere else. Nothing worse than guys who get kicks acting like car gurus by saying well you spelled this wrong

Anyway you don't set a wastgate spring. A springs tension set's it's boost rate as a spring that takes 7psi to compress and open the wastegate is a 7psi spring. Automatics buildboost by brake boosting because they actually put a load on the turbo and that's why you can buid boost at a stop but seems like it dros off or runs inconsistantly during regular driving. Ge a boost leak tester and then go from there.

That is my mistake for lack of knowledge with the external wastegates, I also missed the auto tranny as well... sorry bout' that tcavenger...

 

[VelocitàPaola]

He's from canada so go play english teacher somewhere else. Nothing worse than guys who get kicks acting like car gurus by saying well you spelled this wrong

WTF

They speak English in Canada, even in Quebec... there's no excuse for poor grammar/spelling. OP, you'll really need to try harder while writing posts. I had to completely re-write your original post before I could understand what your question was. Firefox comes with a built-in spell checker and IEspell accomplishes the same effect for IE users.

 

[totaleclipse_05]

Well are you using only this?


Also type in other mods you have done, everything.

What?

 

[Slippi84]

WTF

They speak English in Canada, even in Quebec... there's no excuse for poor grammar/spelling. OP, you'll really need to try harder while writing posts. I had to completely re-write your original post before I could understand what your question was. Firefox comes with a built-in spell checker and IEspell accomplishes the same effect for IE users.

Understood but if you have ever talked to a canadian over the phone and I know you have paul the way we use words and the way they use words is slightly different like talking to white kid trying to use ebonics.(no affense meant by the anaolgy to any candians just the only analogy I could think of at the time)

 

[WarSaw]

Understood, but if you have ever talked to a canadian over the phone, and I know you have Paul, the way we use words and the way they use words is slightly different. It's like talking to a white kid trying to use ebonics. (No offense meant by the analogy to any canadians, just the only analogy I could think of at the time)

Proper punctuation is used in both countries.

On topic, we need more feedback to help the OP.

 

[Slippi84]

Proper punctuation is used in both countries.

On topic, we need more feedback to help the OP.

Says english teacher number two who says nothing about the problem

I already said it has boost leak written all over it. He has a IC and he bypassed it. BAD MOVE. You are forcing hot air into you engine and greatly increasing the chance of knocking. Fix or replace the IC becaue that was probably your boost leak and get back to enjoying your car.

 

[tcavenger99]

thanks for the input (cheers)

ok i am realy sorry about the spelling. Sometimes when i type i do not look it over it after BIG MISTAKE . Anyway replaced the wastgate ,it was leaking thanks all , plus boost leak .Also innercooler is back on my buddy plastic welded it and it holds . Now when i drive 5 psi i reach then it holds for a while and then drops off,yet there doesent seem to be any kind of turbo pull?? Is this just because of such little boost ,also it seams that i have to realy hit the gass to get any response. I still have the cat on the car thought it might be that . or is this because its a auto(soon to be swaped ) one guy said put a spring on the wastgate and see if boost increases. I wouldnt do this yet i have bin waiting on my boost controler for a month and a half now (dam e bay )

o yea if spelling or anything is out of place sorry once again after all i am canadain plus i live on the east coast lool

just went for a run 5 psi then slowly decreases (boost leek) what do you say