Exhaust problems/questions

[senseikrang1]

Hi,

I have recently installed a turbo back system which is 3" - DDP, magnaflow metallic core cat and dual tip magnaflow exhaust(all 3" piping turbo back)

The day I installed it, it drove well and felt strong, etc. But as of recent (not sure if this was happening at the beginning) I noticed the turbo doesn't spool until 4000 rpm....for most of the gears(lower)

I also noticed that on the second gear, the car feels like is is skidding(vibrates)when you accelerate.

I changed all the vacuum lines and I have heard that when you install a new exhaust vacuum leaks become more noticible due to back pressure(pops). Once in a while I hear some really loud pops, anybody know how to cure this? or this part of having a turbo engine with a large exhaust. The only pipe I know is cracked and needs to be changed is the big rubber pipe that connects to the cam cover.

If anyone has experienced any of the above mentioned it would be great to hear your feed back.

Thanks,

 

[92TealSupra]

I guess there are some questions that need to be addressed first off.

Is your turbo stock, after market, upgraded ct?

What other changes have you done with the car?

Have you fixed the PCV hose yet?
l
Does this happen at full acceleration? half, into boost? 1/2 boost?

When you answer these I will be able to help you a lot more, when I added just a 3' down pipe I had better torque, my top end though was slower, because I still had a stock turbo on it, when you say you lose power what do you mean by that what speed are you at when this occurs?

The backfire would be your loud noise, and for now you may just have to deal with that, when you upgrade a bigger exhaust this is likely to happen,

 

[senseikrang1]

Thanks,

It is a stock turbo. The upgrades as per the engine are as follows:

cold air intake, Ceramic IC hard pipes - Ceramic "Accordion" pipe - Ceramic upper rad pipe, PWR racing rad, Greddy Type R BOV, upgraded silicone vacuum lines...

Some of that obviously has nothing to do with the exhaust..

I did not fix the PVC hose yet, most likely needs replacement as it is dry rotted.


"Does this happen at full acceleration? half, into boost? 1/2 boost?"

If you are referring to the "pop" after i've boosted it-not all the time though.

I guess there are some questions that need to be addressed first off.

Is your turbo stock, after market, upgraded ct?

What other changes have you done with the car?

Have you fixed the PCV hose yet?
l
"Does this happen at full acceleration? half, into boost? 1/2 boost?"

When you answer these I will be able to help you a lot more, when I added just a 3' down pipe I had better torque, my top end though was slower, because I still had a stock turbo on it, when you say you lose power what do you mean by that what speed are you at when this occurs?

The backfire would be your loud noise, and for now you may just have to deal with that, when you upgrade a bigger exhaust this is likely to happen,

Does this happen at full acceleration? half, into boost? 1/2 boost?

 

[Rennat]

isnt backfiring after a full throttle pull due to the TPS not being adjusted right? or venting the BOV will do it to i was told...

 

[92TealSupra]

your silicone hoses are they a kit or did you buy them from somewhere?

Well with a stock exhaust you will lose power top end, so yes adding what you did do makes sense then, can you compensate for it though by adding a larger turbo or boosting your stock one ( which is going to ruin it faster ) a little like 3-4 psi. I am wondering if you're runnign to rich back fire has never been my strong point I will do some research though.

 

[Poodles]

The exhaust will raise boost causing boost leaks if everything isn't attached well enough. It would also cause more lag...

My car spools EARLIER with the same mods...

 

[92TealSupra]

The exhaust will raise boost causing boost leaks if everything isn't attached well enough. It would also cause more lag...

My car spools EARLIER with the same mods...

Poddles with a stock turbo bigger exhaust do you think you would lose power at the top end, I know I did..

 

[Rennat]

on a turbo car you should have MORE power on the top end with a 3'' exhaust.. if you 'lose' power you need to check over your car and make sure everything is operationg properly...

3'' exhaust = less backpress = easier on the turbo to boost

 

[Poodles]

Nope, gained power, and faster spool.

Like I said, boost leak...

 

[senseikrang1]

All the silicone lines came from a kit I bought from Hose Techniques....

I will take another look at all the hoses to ensure they are on proper, the only line now that I think of it that I didn't change was the one leaving the "Accordion pipe" below. I have a boost controller-maybe I should install that at the same time.

To double check here, to install the Boost Controller one end receives the vacuum hose from the "accordion pipe" and the second hose runs from the Boost controller to the access point where the vacuum hose from the "accordion pipe" would fit into? - is this rite?

To verify, the cracked pipe leaving the side of the cam cover would not affect the exhaust system-leak wise, correct?

Like Poodles was saying, in regards to faster spool-I was getting that at the beginning, something might have came loose. Now my concern is if I find none of the vacuum hoses loose.....what else could I check.

Thanks,

 

[Rennat]

a boost controller has nothing to do with accordian pipe... the boost controller goes between the line from the compressor housing (front of the turbo) and the line on the wastegate.

and the only vacuum hoses on the stock intake are for PCV, BOV, and the power steering... did you use a vacuum diagram when you redid the lines to make sure you had them running correctly?

 

[Poodles]

boost leak in the intercooler pipes or you have an exhaust leak before the turbo...

 

[mkiii222]

boost leak in the intercooler pipes or you have an exhaust leak before the turbo...

Agreed.


And Rennat, he's talking about the vacuum hose that comes off the bottom of the accordian (PS). And you forgot the ISC line.

As for your cracked hose. I'm guessing you mean the one to the side of the filler cap, behind the alternator? It won't cause enough of an effect to notice since it's just an oil drain, but you should get it fixed. That piece runs ~$25 iirc and it only takes 20 minutes to replace (well, mine took 20 because the po had taped it and yanking it loose the clamp sliced my finger so I stopped for 10 to tape that up/stop the bleeding).

 

[senseikrang1]

Hi,

I just came back from the shop, I had my car on the hoist we checked all the connections and the temperature of the piping before and after cat-to make sure there isn't an issue with the cat. Seems everything is in order, the hoses are all new and tight, the exhaust is not loose....

I know my clutch is seriously bad, could this contribute to the lose of take off power and why the car trembles on 2nd gear?

Please advise,

 

[Poodles]

Yeah, if it's slipping bad than it could feel gutless...

 

[randandrawson@v]

the vibration in 2nd might just be the exhaust vibrating.
just did an accord system that was barley touching a heat shield.
first 2 gears under load felt and sounded like the car was coming apart.

backfire could be either ignition, fuel, or valve train.

burnt valves can backfire, do a leakdown test.
dodgy ignition will load up gas in the turbo and make all kind of wierd pops.
too rich, too lean also. Check the plugs for mixture read, and check the wires are tight on the plugs. That damn tin over the valley is a bitch for getting the wires to snap on tight.

I've got a 3" from the elbow back, no cats, and an obnoxious muffler.
Bone stock other than that. spools great, top end is great, fuel cut sucks.