Questions about wastegate and ddp

[suprahero]

I have been complaining on here a little about my ddp causing my car to hit fuelcut. A guy I met today at a parts store came over to look at my car. I took him for a ride down the road in it to see if he could answer a couple of questions. My car whistles when you take off, even taking off very slow. He saids that my wastegate is open and therefore it's letting air go through the divorced pipe. Sounded good to me. He also said that my wastegate is getting stuck open and that's why it doesn't feel like I'm getting very much boost even though I'm reading about fourthteen pounds. He has an Mr2 with 18psi, and he said that he had the same problem a while back. He took his ddp off and said you could see whrere the wastegate was getting hung on the dp. He took a dremel tool and bored the hole out bigger and hasn't had the problem again. Has anyone else experienced this problem? Does it sound feasible? Thanks alot.

P.S. His MR2 is running 7.2's in an 1/8 at 96mph and 11.2 in a quarter. I haven't seen any timeslips, but that's what he told me. Believe it or not..............lol

 

[suprahero]

Come on guys, don't tell me this is the first time no one has an opinion. I'm going to take it the ddp off and see if their are any marks and hope that their is.

 

[sleepersupra]

Come on guys, don't tell me this is the first time no one has an opinion. I'm going to take it the ddp off and see if their are any marks and hope that their is.

i think it is possible and its worth a try

 

[Bishop92t]

Wastegate has no direct effect on FCO's boost level. Is this a custom DDP or BIC DDP? If the wastegate dump tube was too small or restrictive somehow it could cause overboosting. Other then that all that a wastegate could do is stick shut or not open enough and cause overboosting. Or stay open too much and cause little boost. Without a mod listing of your car it's hard to give you any information beyond that.

 

[souprat]

He saids that my wastegate is open and therefore it's letting air go through the divorced pipe. Sounded good to me. He also said that my wastegate is getting stuck open and that's why it doesn't feel like I'm getting very much boost even though I'm reading about fourthteen pounds.

if the wg was stuck open you would not be able to make boost or would take a long time to build boost. maybe you ment BOV? pull 'yer ddp off and have a looksee at the wg. put some pressure into the wg and see if it moves any and if it does then see if it returnes to the origonal position. and if you want to check clearance between the ddp and wg put alittle car wax on the wg door, put the ddp on and then move the wg to full open. take the ddp off and look for wax on it.

 

[suprahero]

My mods are as follows: 550's, walbro 255fp, lexus afm, afpr, Garrett to4e, bic ddp, 3" exhaust, safcii, intercooler from Big Aaron with 2.5" lower ic pipe, stock upper ic pipes. I think that is about it. Long story short car was running great, blew a hg racing at the track, replaced it with toyota hg. While it was apart I went ahead and installed bic ddp. Since then it doesn't feel like it is boosting strong although my boost gauge shows it's boosting up to 16-18 psi. This guy I met saids that his car did the same thing and it was because the wastegate was getting stuck and letting boost leak through the divorced pipe. When I take off it whistles out of the divorced pipe even when not under boost. I'm going to remove the down pipe sometime this weekend and see if their is any evidence of this. Thanks for any help.

 

[xarewhyayen]

Maybe you have something loose? exh manifold? turbo bolts? maybe even intake manifold tends to make whistling and that would cause you to hit fuel cut early cuz you're losing measured air. Check around and make sure everything is nice and tight. exhaust "leaking" out of your ddp wouldnt do much to hurt ya. If the wastegate stayed open, itd be mighty hard to boost. If it was stuck closed youd hit fuel cut pretty quickly though.

 

[suprahero]

Thanks, I'll check all bolts again on manifold. I double checked them when I installed it, but I'll check again.

 

[Bishop92t]

Was your BIC DDP specifically made for your turbo? The bolt pattern on your turbo can be the same but that doesn't necessarily mean the wastegate is in the exact same location or even opens in the same direction. That could definitely be interfering with its operation. A fairly easy way to test would be to remove the bolts holding the wastegate on, and then verify that you can move the wastegate arm easily and to the correct angle. Also removing the DDP you might see signs of interferance.

 

[souprat]

This guy I met saids that his car did the same thing and it was because the wastegate was getting stuck and letting boost leak through the divorced pipe.

this is not correct. i just came back to this thread(thanks for the rep!) boost is on the oppisite side of the exhaust and cannot leak out of the WG. do what everyone else is saying to look for interfearance between teh ddp and wg, check for proper wg operation and then you could always look for a boost leak while your at it all.

 

[suprahero]

I checked everything and I'm no closer to solving my problem. I thought I found the reason it was whistling. The small vacuum hose that runs from my wastegate to the turbo had a good sized hole in it. Replaced it with a new hose and it still whistles. My wastegate is supposed to be set at 14 psi. Does that mean it shouldn't open until I have reached 14 psi? It shouldn't even be loud until 14 psi, correct? It sounds like it opens up at like 8psi. What do you think?

 

[souprat]

normal. wastegates do not pop open all at once when you get to full boost. they "crack" open at a pressure much lower than full boost. remember, the wg is a spring and a diaphram. if you push on a spring with alittle force, you can compress it alittle bit, push harder and compress it alittle more. so when you have 8psi your wg starts to open just alittle and by the time you at 14 its all the way open. that means your trying to build boost while your wg is venting gas, unfortunate but unavoidable. did you check for boost leaks? how bout shaft play? did you check your wg operation and clearance?

 

[boost fiend]

which turbo is it? iirc, i have heard of the wg on ct 26's devolping a crack on the flapper door for the wg. maybe is is by the door, i dont recall at the moment. just a lil info i did remeber.

 

[suprahero]

I have a garrett to43 mounted on my old housing.(I guess it's called a housing) I did see a hair line crack about 1/4" long right above where the wastegate opens. This is really driving me crazy. I can not find any boost leaks anywhere.