unintentional boost leak fix?

[gsxonthebeach]

My car "used to" detonate horribly bad when I purchased it and I have driven it quite modestly because of that reason. About 3 weeks ago I decided to redirect my wastegate dump tube into my down pipe to eliminate the loud noise during boost. Ever since I did that I have taken it up to 5 and 6000 rpms where I normally detonate, only for a quick second, but I have yet to hear or feel any kind of detonation. Could I have unintentionally fixed a boost leak, or can I just not hear it anymore?

 

[TSiAWD666]

Your exhaust has nothing to do with your intake as far as leaks go.

 

[dlb21]

What were your detonation symptoms... the only thing I can think of is that your engine bay is much cooler now that you don't have exhaust dumped in there. But unless you did anything with the intake then you havent fixed any boost leaks...

 

[r1991_4g63t]

boost leaks also wont cause detonation

 

[xsboost]

By no means am I trying to insult your intelligence but are you mistaking detonation for a backfire or fuel cut? Although I don't know what your wastegate dump has to do with fuel cut unless you unintentionally fixed boost creep by rerouting the dump.

 

[Freerevving]

Exhaust gas helps reduce detonation... via the EGR valve

but you were probably hearing something else

 

[Artago]

Exhaust gas helps reduce detonation... via the EGR valve

but you were probably hearing something else

Huh?!?! EGR valve reduces detonation? Sorry, just a bit confused at this statement. Please clarify.

Tom

 

[1tgalon]

I would also like to know how the EGR helps reduce detonation. To the OP, I have to ask though, how were you hearing audible detonation over your dump. If it is THAT loud I think you may have bigger problems. I agree that maybe you are mis-using the term detonate, and maybe you are seeing something else like a backfire. The only thing that seems backwards with the fuel cut is that usally putting on an external dump helps with boost creep.

To add, when you "felt" it detonate what did the car do? Did it fall on its face, buck, etc.? You really need a logger.

 

[Jetrosr]

I would also like to know how the EGR helps reduce detonation. To the OP, I have to ask though, how were you hearing audible detonation over your dump. If it is THAT loud I think you may have bigger problems. I agree that maybe you are mis-using the term detonate, and maybe you are seeing something else like a backfire. The only thing that seems backwards with the fuel cut is that usally putting on an external dump helps with boost creep.

By introducing inert gases to allow cooler combustion temperatures. Exhaust gas recirculation - Wikipedia, the free encyclopedia

 

[olmytsi]

Your knock sensor could have been picking up the wastegate dump as knock...that's the only thing that could explain it.

 

[1tgalon]

By introducing inert gases to allow cooler combustion temperatures. Exhaust gas recirculation - Wikipedia, the free encyclopedia

Learn something new everyday. olmytsi, I know I have heard of the open dump wastegate issue before but I thought most people agreed that it wasn't an issue. I have run two setups with open dumps and have been able to get zero knock, but I am guessing there is an exception to every rule. Either way the car is running better according to the OP so .

 

[gsxonthebeach]

I would also like to know how the EGR helps reduce detonation. To the OP, I have to ask though, how were you hearing audible detonation over your dump. If it is THAT loud I think you may have bigger problems. I agree that maybe you are mis-using the term detonate, and maybe you are seeing something else like a backfire. The only thing that seems backwards with the fuel cut is that usally putting on an external dump helps with boost creep.

To add, when you "felt" it detonate what did the car do? Did it fall on its face, buck, etc.? You really need a logger.

When I bought my front mount from a local dsm shop he had me swing around after work to log the car and do some light tuning, thats when he explained the problem with the car in words, which was the detonation. Now, for all I know he could have been lying, but I did some research on the subject (obviously not enough to figure out it had nothing to do with my exhaust, so please excuse the rookie move there) and I am pretty sure it's detonation. Right at about 5-6000 rpms after 1st gear, so 2nd-5th, the car will remain at 10 psi (which its set at) and then you will distinctly hear the "detonation", which sounds like a gun shot, and the psi will jump down to 0 and then shoot immediately up to 15 psi which is usually when I let off the gas and start crying. It could very well be a backfire, so I will read up on that, but I am almost positive its detonation. The reason I thought I may have fixed a boost leak was because I took off the o2 housing. Sorry for the loooong post.

Learn something new everyday. olmytsi, I know I have heard of the open dump wastegate issue before but I thought most people agreed that it wasn't an issue. I have run two setups with open dumps and have been able to get zero knock, but I am guessing there is an exception to every rule. Either way the car is running better according to the OP so .

Well I hope the car is running better, and I didn't just make a silent killer, haha.

 

[xxsupralvrxx]

that sounds like a fuel cut to me....

 

[gsxonthebeach]

that sounds like a fuel cut to me....

so if this were the case I should get bigger injectors and dsm link and tune it?

 

[1tgalon]

It would be probably one of the best investments you could make for your DSM. DSMLink does remove the airflow fuelcut. I saw you had 550's, with link you would be able to step up quite a bit in the injector size like 850-1000cc (I know you can go more but I also know link can have some problems with injectors like 1600's) and really see what that e316g can do.

 

[dlb21]

That is going to be your best bet...bigger injectors and some way to tune the engine. This will also help diagnose your system a little better as well... how are you controling your 550's ???

 

[1992awdlaser]

The EGR valve does nothing for detonation at WOT conditions. This is because the EGR valve is never open at wot.

 

[gsxonthebeach]

That is going to be your best bet...bigger injectors and some way to tune the engine. This will also help diagnose your system a little better as well... how are you controling your 550's ???

they are controlled with greddy emanage, which the previous owner decided to get. So I am in no way endorsing that for our cars. But I have had those 850s and dsm link on my list for this summer and I should have them by September, so I will let you all know how that goes. But thank you for the help everyone.

 

[PieEyedPiper]

Soooo much speculation.

gsxonthebeach, why don't you make a log and see what really going on?

 

[gsxonthebeach]

Soooo much speculation.

gsxonthebeach, why don't you make a log and see what really going on?

Because I overcomplicate things, haha, no that is a fantastic idea (I think someone mentioned it earlier, too), so I will go find a logger.