I have been working on tuning a friend's car recently and even though his afr's are perfect and his timing maps are fine the car simply does not want to rev out. At first the car would buck and sputter like crazy after a certain rpm, but after gapping the plugs down to .03 it took care of that problem. Now the car will rev all the way to redline and it drives really smooth, but it just seems hesitant to rev out. He has his wastegate dumptube running into the downpipe right at the bend coming off the turbo. Could this be causing a large amount of turbulance in his exhaust flow? I know this car should be much faster than it is.

 

**Rolls up his copy of Maximum Boost and smacks SOHC_MShue upside the head with it**

hehehe seriously though, IIRC the reason is because of exhaust gas turbulence. I'll see if I can find the text in MB later on, cause I cant do it right now. Getting too tired and cant see straight.

 

Well duh I know its turbulent thats why i'm asking how bad of an effect it is having on it . Trust me if it was my turbo setup i wouldn't have routed it there either. I'm just wondering if this might be his problem.

 

bump

 

Someone on here posted a 20 WHP gain by opening up the dumptube that was routed in right past the turbo. I can totally see this making the motor slower to rev on the high end.

 

yea i'm going to tell him to take the dumptube off and see how it feels because it is waaay slower than it should be.

 

It's my car.

Hey Matt, I'm doing it soon, I'm calling Anthony today (the guy who fabricated my kit) and talking to him about removing the dumptube and making it go straight into the atmosphere and seeing how loud it really is. But I'm definetley going to have him move it.


Modified by meltman1234 at 11:09 AM 5/9/2005

 

you should try flipping the wastegate around one day so it is sticking straight up at your hood and dumping into the air. Just make a couple of pulls and see if it feels better. I bet you will feel a huge increase in power. Be careful though because you will probably need a bit of a retune then.

 

I'm going to try it today if I have time. It's going to start sounding like Ian's car. Haha

 

yea man let me know for sure. I am interested in seeing how it runs after that.

 

It ran shittier after the wastegate was turned around. It was running smoothly before hand then I got on it and in first gear it started ******* up. But anyways I'm going to recheck the spark plug gap, make sure it's correct down to the last millimeter.

 

it may be ******* up because you are making way more power and it needs to be richened up. Its also probably not running great because you have a massive exhaust leak. Where it used to be going to the wastegate. Go ahead and get anthony to rewheld it further down or simply run it with an open loop dump that doesn't go back into the exhaust. I guarantee you that you are losing a lot of power either way because of the placement whether that is your main power loss problem or not.

 

Possibly we can try it at your house sometime when we can change the tuning around if that's alright with you.

 

yea we can do that if you want. Go ahead and try to schedule something with him to get that dump changed first though.

 

Stupid computer double posted


Modified by meltman1234 at 11:39 PM 5/9/2005