I keep having a knock in 4th gear between 6-7000rpms.Its been going on like this for a year know.Sometimes it does not knock at all when i do a pull and then in the next run it does.I have a turboback,S1 cams,bigger intercooler,stock turbo.My car was tuned for 25psi but even with lowered boost like 23psi it still knocks. Any ideas what could be causing this?I was thinking it may be a walbro fuel pump but iam not sure.

 

Do you have the ability to log your car while this is happening?
Like Evoscan and a Tactrix cable.

What knock sum is your fast CEL set at?

I'd quit doing WOT runs in 4th until you get this sorted out.

Of course you HAVE been running it for a year like this???

 

no i dont have a tactrix cable. i am backing off the throttle when i see it flashing. i guess im gonna have to see a tuner to fix that issue.

 

anyone in Palm Harbor area that could look into my map so we would know how hard it knocks?

 

Could be knocking due to the lower boost...but too rich at that point for what It was tuned for...

 

I think you are right because with lowered boost i saw 11:2 afr and thats with Epm dump so its more like 10:8afr or lower. I lowered the boost just to see if it would knock. Iam also thinking it could be a phantom knock too.I just stay off boost for now and wait till I'll save some money for a re tune.

 

I have decided to change my Epm dump for a Megan o2 housing and at the same time go with Megan downpipe for Evo9.My dump pipe is touching Licp and its too close to downpipe.That might cause the problem+my XS engineering dp is touching T-case. I put a DEI wrap around it just to be safe but it still bothering me a lot.I guess i would have to re tune my car after the install.

 

Buy a tactrix cable and log your own car..The best part is if you find a good tuner on line either mellon or arron from english racing then your set.

 

Thanks for the referral achilles.

Cinek, check out our Tuning section on www.mellontuning.com It details how we can fix your tune remotely with ease. There's a list of items you'll need and even a video tutorial on how to use the software. http://www.mellontuning.com/index.ph...dex&cPath=1_28

FYI, many tuners only work on 3rd or 4th gear pulls at the dyno or stretch of road. That will get you in the ball park at best. When you row through several gears you will create much more heat and that can induce knock that you've never had a problem with during single gear pulls. We can adjust your tune so that it works in every scenario, not just one

if you're unfamiliar with Mellon Tuning I would suggest doing a search for threads with Mellon in the title and see what our customers have to say. You won't find a single negative review and loads of very happy customers.

 

Thanks Mellon Tuning for your advise!.I know you are a very good tuner I've heard nothing but best about you.What if I will change my Epm o2 for a Megan one, would this be a problem with a mail tune? If not then I will find somebody that can help me out so you can repair my tune.

 

it's possible that it will make a change to the tune, but if you have a wb02 gauge and logging capability with evoscan you can monitor the situation.

 

then I guess I would have to buy a custom tune from you right? just to have it done the right way because i want no issues. Its my DD and I like to get on it without being worried and paranoid.

 

getting a tune after changing mods/boost/octane is always a good idea to keep it in great shape so you can run it hard and not have to worry about it.