bad remap??

rs8

what really happens with a bad remap?? have seen cars on done deal saying "bad remap will have to be remaped again"? i take it theres cowboys out there

Blazer

rs8 wrote: »

what really happens with a bad remap?? have seen cars on done deal saying "bad remap will have to be remaped again"? i take it theres cowboys out there

There'd be a few I'd say, also there are kits that you can get that apply a standard remap to your car as well.so it's not just cowboys but people trying to save a few bob ...a bad remap would be one that either allowed too much power etc that would involve a lot more wear and tear on cars such as turbos, clutches, gearboxes etc.
It also increases the torque to give you better acceleration in higher gears..
A proper remap would be where your remap is customized to your car not a standard one for all remap.

Have a read below and especially read the Liam0's last comment as to why the remap was a bad idea for his car.
A cowboy on the other hand would take a standard remap and apply it regardless without doing the checks below.

http://vagdrivers.net/forums/index.php?showtopic=31843

http://vagdrivers.net/forums/index.php?s=&showtopic=31843&view=findpost&p=308624


I'd be very wary buying one of those cars that was badly remapped and would only consider it if it had done minimum mileage since the remap. Otherwise potentially you'd be looking at some serious repairs and bills down the line.

Anan1

A bad remap might increase boost without adequately increasing fuelling. This will cause detonation, which has the potential to blow a hole in a piston or worse. I wouldn't touch.

Gary ITR

Anan1 wrote: »

A bad remap might increase boost without adequately increasing fuelling. This will cause detonation, which has the potential to blow a hole in a piston or worse. I wouldn't touch.

Generally boost isnt touched wothout physical mods. Remapping is fine tuning the ignition timing and afr's. Most bad maps I've seen are cars adjusted too faror run to lean/rich which causes its own problems

Anan1

Gary ITR wrote: »

Generally boost isnt touched wothout physical mods. Remapping is fine tuning the ignition timing and afr's. Most bad maps I've seen are cars adjusted too faror run to lean/rich which causes its own problems

I'm no mechanic, but isn't the afr a function of both air and fuelling - ie, both have to be increased in proportion to one another in order to give more power?

Nissan doctor

Anan1 wrote: »

I'm no mechanic, but isn't the afr a function of both air and fuelling - ie, both have to be increased in proportion to one another in order to give more power?

AFR is Air Fuel Ratio, this ratio has to kept optimum through the rev range.

A poor map, especially one which leads to a lean running engine at high rpm, can very easily destroy the engine.

Anan1

Nissan doctor wrote: »

AFR is Air Fuel Ratio, this ratio has to kept optimum through the rev range.

A poor map, especially one which leads to a lean running engine at high rpm, can very easily destroy the engine.

I was under the impression that this was often a result of increased boost without enough fuel, ie more air + same fuel = running too lean = detonation?

Gary ITR

Anan1 wrote: »

I was under the impression that this was often a result of increased boost without enough fuel, ie more air + same fuel = running too lean = detonation?

It's not the boost changes that cause that though, well they can but as I said without physical mods boost is left alone.

I did have the pleasure of sitting in an EVO assisting the tuner which was running 2bar boost and hitting 600BHP, I thought it was going to launch the Dyno out the door.

Anan1

Gary ITR wrote: »

It's not the boost changes that cause that though, well they can but as I said without physical mods boost is left alone.

Again i'm not a mechanic, but i'm pretty certain that my car at least can be remapped to increase boost. Isn't the ability to increase boost the reason why performance gains from remapping are so much greater in turbocharged than NA cars?

Gary ITR

Anan1 wrote: »

Again i'm not a mechanic, but i'm pretty certain that my car at least can be remapped to increase boost. Isn't the ability to increase boost the reason why performance gains from remapping are so much greater in turbocharged than NA cars?

You can map to increase boost but mapping for a smooth AFR and tuning the ignition timing make far greater and safer gains. Increasing boost isn't a safe option on most cars

Anan1

Gary ITR wrote: »

You can map to increase boost but mapping for a smooth AFR and tuning the ignition timing make far greater and safer gains. Increasing boost isn't a safe option on most cars

I was certain that you increased both boost and fuelling for more power. It was recommended to me that I use an uprated fuel pump when remapping my car for this very reason.

Gary ITR

Anan1 wrote: »

I was certain that you increased both boost and fuelling for more power. It was recommended to me that I use an uprated fuel pump when remapping my car for this very reason.

Uprated fuel pump = physical mod

Increasing boost needs a lot more fuel to keep it safe but most mapping is done simply by tuning the afr(without adjusting boost) and ignition timing. Take the 1.8T VW engine, without touching boost it can go from 150 to 180, with a boost fiddle and injectors from an S3 it can break 200.

Anan1

Gary ITR wrote: »

Uprated fuel pump = physical mod

The way it was put to me was that my standard fuel pump was a bit marginal anyway, and that it wouldn't last long under greater load.

Gary ITR wrote: »

Increasing boost needs a lot more fuel to keep it safe but most mapping is done simply by tuning the afr(without adjusting boost) and ignition timing. Take the 1.8T VW engine, without touching boost it can go from 150 to 180, with a boost fiddle and injectors from an S3 it can break 200.

But if you don't increase the amount of air getting to the engine then how can you do more than tinker with the fuelling without sending the afr way off? I'm not disagreeing with you here, I genuinely don't get it.

Re the bad remap making a car run lean thing, it was told to me by a guy called Barry Waterhouse when he remapped an integrale from 185 to 240bhp for me. That was in 98, so things might have changed since.

Gary ITR

Anan1 wrote: »

The way it was put to me was that my standard fuel pump was a bit marginal anyway, and that it wouldn't last long under greater load.

That your Subaru?

Anan1 wrote: »

But if you don't increase the amount of air getting to the engine then how can you do more than tinker with the fuelling without sending the afr way off? I'm not disagreeing with you here, I genuinely don't get it.

Re the bad remap making a car run lean thing, it was told to me by a guy called Barry Waterhouse when he remapped an integrale from 185 to 240bhp for me. That was in 98, so things might have changed since.

Sorry I'm probably explaining this arseways, I hate typing on my 'smart'phone :rolleyes:

Basically you work with whatever air you have and adjust the fueling to suit. With my N/A car I'm looking for in around 13.5:1 so I tune towards that, the ignition timing is what really makes the power though, adjusting the IT will lead to more efficient cylinder fill and that makes great power.

Anan1

Gary ITR wrote: »

That your Subaru?

That's the one.

Gary ITR wrote: »

Sorry I'm probably explaining this arseways, I hate typing on my 'smart'phone :rolleyes:

Basically you work with whatever air you have and adjust the fueling to suit. With my N/A car I'm looking for in around 13.5:1 so I tune towards that, the ignition timing is what really makes the power though, adjusting the IT will lead to more efficient cylinder fill and that makes great power.

So why do turbocharged cars show much greater improvements than NA? Feel free to leave it until you're at a proper keyboard.;)

Gary ITR

Anan1 wrote: »

That's the one.

Pump from a WRX STI Impreza is good for 450BHP or so, that should be more than enough for ya

Anan1 wrote: »

So why do turbocharged cars show much greater improvements than NA? Feel free to leave it until you're at a proper keyboard.;)

A tuned B18 N/A Honda can run an AFR of around 13.5:1, any lower than that is too rich. Because of the nature of a Turbocharged machine it can run a much lower figure that that safely. I could ramp up the fuel on the N/A car but it wouldn't last very long because it's not getting enough air. Factory ECU's are tuned to run quite conservatively too

Anan1

Gary ITR wrote: »

A tuned B18 N/A Honda can run an AFR of around 13.5:1, any lower than that is too rich. Because of the nature of a Turbocharged machine it can run a much lower figure that that safely. I could ramp up the fuel on the N/A car but it wouldn't last very long because it's not getting enough air. Factory ECU's are tuned to run quite conservatively too

So basically a turbocharged car is getting more fuel with the same air for more power, whereas I thought it was getting more of both?

Gary ITR

Anan1 wrote: »

So basically a turbocharged car is getting more fuel with the same air for more power, whereas I thought it was getting more of both?

That's about it really, for a stock engine/setup anyway. I, like yourself, assumed boost was increased, I asked my mate about it and he explained it to me

Anan1

Gary ITR wrote: »

That's about it really, for a stock engine/setup anyway. I, like yourself, assumed boost was increased, I asked my mate about it and he explained it to me

Every day is a school day.

ATWR Eoin

rs8 wrote: »

i take it theres cowboys out there

If I ever found out who the guy was that remapped the vRS I would ram the parts that were replaced where the sun doesn't shine. The pitfalls of a poor quality remap are staggering. I had so many issues with my last car that I got rid of it after 12 months. Don't even consider a car like those when you see them advertised.

Gary ITR

ATWR Eoin wrote: »

If I ever found out who the guy was that remapped the vRS I would ram the parts that were replaced where the sun doesn't shine. The pitfalls of a poor quality remap are staggering. I had so many issues with my last car that I got rid of it after 12 months. Don't even consider a car like those when you see them advertised.

I'm not convinced it was a bad map, I think it was a case of the dealer blaming the map.

ATWR Eoin

Gary ITR wrote: »

I'm not convinced it was a bad map, I think it was a case of the dealer blaming the map.

The DPF's on the CR's aren't that prone to failure. It failed after a lot of mileage in ideal conditions. I don't think a thorough job was done.