Al,
I enjoyed your dyno flash last month and was satisfied. But in the last few weeks I have noticed a loss in power. I have never dynoed the car, so I am just going off my butt-dyno. After the tune initailly I felt a large increase in power and both top end and bottom end power was noticeably greater.

I haven't changed anything about the car, but I have noticed the power loss. Someone said I might have gotten some bad gas, so I ran it out and tried another tank... same thing. I then decided to disc the battery and reset the ECU, which I did. This worked, and the power was back, but only for a short time. I was told by another member that my engine was probably sensing knock and is "fixing" itself causing the power loss.

Al please help, am I am stumped, and as it stands now my car feels slower then when I got my tune last month! Please help....

 

Go through and check all intercooler piping and then tighten the clamps that are on the bov.

 

you are also probably getting used to the power...also, sometimes if you get a bad tank of gas, the stock computer might start to pull a little timing. just reset it by dissconnecting the negative terminal of the battery and letting it be for about 15 minutes.

 

Check all vac hoses - there are some that connect to the egr valve which dont have any zip ties on them which frequently fall off.

Also - we find that sometimes people get used to the power and over time the car starts to "feel" slow. I can assure you it would "feel" even slower with the stock tune re-installed !

In most cases people have a boost leak or other mechanical issue which occurs. Most of the time guys who are saying what you are saying we put on the dyno and their car is still making the same power - they just got used to it.

 

woops...sorry i just finished reading your post...you already did that. i guess i should not just skim over posts....SORRY

try it again though. i do this every so often. also, try using the same gas that you got your tune with and stay with that company

 

Looking at his tune - I seriously doubt that fuel is an issue as we ave guys who run 91 octane cali **** gas with almost the same ign timing settings

Especially with the HKS RS KIT the reflash is very sucessful and there is little or no room for error - that filter procuces very consistant and even results

The funny thing about doing reflashing is that when people's car do not run perfectly - the first thing they suspect is the reflash. I think many people are used to other kinds of cars like Subarus or 350 Z's that have ecus which constantly change the tune and alter the timing and a/f ratios.

On Evos - the reflash tune is very stable and does not change significantly - especially after we have done the so called "Fireball" modification which aides greatly in getting the ecu to remain stable under all conditions.

IN EVERY CASE when we have a car on the dyno which is not making the right power - we find a MECHANICAL issue - such as boost leak, bad plugs, glogged air filter, etc etc which is the cause.

Have a professional mechanic go over the car (who has turbo experience) and if you cant find the cause - then I will be happy to look it over when I return to your area in mid - October

 

Thanks Al... I wasn't pointing fingersat the Flash, although I am sure you are just used to that. I really am just trying to get to the bottom of it. I realize that the car can and will "feel slower" over time as we get used to our newly added HP, but I honestly don't think this is the case this time. I have disc the battery twice now, but never left it this way for 15 min, maybe 5 at the most, so I'll try longer. I also replaced my plugs today, and didn't seem to notice a difference. I changed my HKS air filter last week just incase, although there was only about 3k miles on it. Is it possible to have a boost leak if your guage is still reading ok? Not sure exactly where al the IC piping is but I will try and research that as well.

I was just looking for ECU advice as this is the area I am most inexperienced in... Thanks for your continued support Al and fellows Evo brothers.

 

Does the car feel slow also at night when it cools down outside also - or is it just slow during the day time ?

BTW - the reason why small boost leaks make the car feel sluggish is becuase the stock turbo is basically maxed out and when you have small leaks ou have to make it work that much harder to make the same boost.

I have seen dozens of cars with small boost leaks which felt a bit sluggish and which were making poor power on the dyno.

Wih the HKS RS kit the a/f tuning is basically identical on every car we tune so I seriously doubt the tune is off.

Another possible issue is we have seen situations where the fuel pump is not installed properly and the car is running very lean b/c the fuel pump has fallen down in its housing and there is a leak in the tank

Again - after doing this for a year - you would not believe the stuff I have seen happen on the mechanical side - even a car with bad cam shaft journal clearance from the factory.

When the tune is good - then the car starts to get slow - usually something on the mechanical side has changed.

 

Good advice, thanks. It seems to be just a small problem because otherwise the car is running fine, maybe a boost leak or vacuum. I'll do some more poking. I am planning new mods anyway, so maybe when you come to O-town (orlando) I can get a new tune with my new mods and maybe you'll have some advice hands-on. Thanks again for your time.

 

Main issue is to find a shop that knows how to attach a device to pressurize the charging system

At Pruven we do that paratcially on every 3rd car and just about all the ones we test have a small leak or two somewhere

 

I would guess boost leak. Just this week my bov stopped working 100%. DO you have a boost gauge? If so see what happens if you raise the coost if you can. I can not hold anything more than just under 20psi.