I keep being told it's only done on diesels? Is there really that little to be gained on a petrol engine? I really thought it would be tailor made for some fettling for mpg and acceleration Range Rover 4.4 V8 Autobiography
Mustang Mach 1 (1971 in grabber green)
Honda civic 2.2 diesel
VW crafter with ICE

What made you think that?

There are gains to be had, but by comparison with a turbo diesel engine they will always be smaller percentage wise. This is because it's easy to increase the amount of air that can flow into the cylinders on the TD by increasing the turbo boost pressure. Then just add the right amount of fuel to retain the correct mixture and you get a bigger bang.

On a normally aspirated engine you can't easily increase the airflow without extensive modifications, so the only thing you can do is recover losses already present in the existing map - maybe for economy or emissions reasons, and maybe sharpen up the throttle response as well.

ric355 wrote:

What made you think that?

There are gains to be had, but by comparison with a turbo diesel engine they will always be smaller percentage wise. This is because it's easy to increase the amount of air that can flow into the cylinders on the TD by increasing the turbo boost pressure. Then just add the right amount of fuel to retain the correct mixture and you get a bigger bang.

On a normally aspirated engine you can't easily increase the airflow without extensive modifications, so the only thing you can do is recover losses already present in the existing map - maybe for economy or emissions reasons, and maybe sharpen up the throttle response as well.

I find superchips is always a reasonable guide to what the likely gains can be. Here's the V8 petrol gain from them. They use a conservative mapping strategy usually but even if you assume the aggressive version could return twice as much power (and it definitely won't - more like 1 more bhp!) then the gains are still pitiful:

http://www.superchips.co.uk/search?make=17...riant=1067

hi, heres his number, tell him dave gave you his number and you was told it was 175 inc postage back, you wont find remapping that cheap any were.., he does two types of maps, eco for better mpg and sport, you will always get more bhp out of the diesel hi, send him your ecu and he will flash the eprom and then he will send it back recorded.
here is his web site.www.drka.co.uk
dave
07578261689 (lewis) V8 facelift Range Rover Autobiography 22" wheels.
1976 Harley Davidson Iron Head Sportster

Has anyone had theirs done on the petrol ??

I know 12 bhp gain is it really worth it ?

How much more mpg can you get ?

havnt bothered for reasons stated

on a 2.5 ton car with 290bhp you are not going to notice 12bhp difference....you can barely notice 12bph on a 750kg Lotus Elise

forced induction engines are better of course, so diesels or supercharged/turbo can see noticable gains cheers
bogie

ric355 wrote:

There are gains to be had, but by comparison with a turbo diesel engine they will always be smaller percentage wise. This is because it's easy to increase the amount of air that can flow into the cylinders on the TD by increasing the turbo boost pressure. Then just add the right amount of fuel to retain the correct mixture and you get a bigger bang.

KurtVerbose wrote:

ric355 wrote:

There are gains to be had, but by comparison with a turbo diesel engine they will always be smaller percentage wise. This is because it's easy to increase the amount of air that can flow into the cylinders on the TD by increasing the turbo boost pressure. Then just add the right amount of fuel to retain the correct mixture and you get a bigger bang.

Most, if not all, chipping companies aren't increasing the boost pressure. They're just burning air that's already there. They just get closer to the edge of complete combustion than the manufactures go.

BigJ wrote:

KurtVerbose wrote:

ric355 wrote:

There are gains to be had, but by comparison with a turbo diesel engine they will always be smaller percentage wise. This is because it's easy to increase the amount of air that can flow into the cylinders on the TD by increasing the turbo boost pressure. Then just add the right amount of fuel to retain the correct mixture and you get a bigger bang.

Most, if not all, chipping companies aren't increasing the boost pressure. They're just burning air that's already there. They just get closer to the edge of complete combustion than the manufactures go.

Sorry I call b0llocks on this one. I own my own tuning company and I certainly raise boost pressure with a large amount of other maps.

I remapped my 4.4 M62 engine and it responded very well. The new owner had a 02 4.4 V8 and he noticed the difference as soon as he jumped into mine.

BigJ wrote:

Sorry I call b0llocks on this one. I own my own tuning company and I certainly raise boost pressure with a large amount of other maps.

How about the air filters and all that would that make any if not at all.?

Matt@obsidian wrote:

BigJ wrote:

KurtVerbose wrote:

ric355 wrote:

There are gains to be had, but by comparison with a turbo diesel engine they will always be smaller percentage wise. This is because it's easy to increase the amount of air that can flow into the cylinders on the TD by increasing the turbo boost pressure. Then just add the right amount of fuel to retain the correct mixture and you get a bigger bang.

Most, if not all, chipping companies aren't increasing the boost pressure. They're just burning air that's already there. They just get closer to the edge of complete combustion than the manufactures go.

Sorry I call b0llocks on this one. I own my own tuning company and I certainly raise boost pressure with a large amount of other maps.

I remapped my 4.4 M62 engine and it responded very well. The new owner had a 02 4.4 V8 and he noticed the difference as soon as he jumped into mine.

So what are your expected gains then on the 4.4 V8? I am more interested on mpg but extra power is always welcomed

Cheers big j. The LPG will be next year, was just curious if there was anything tobegained before hand. Thanks again

BigJ wrote:

Matt@obsidian wrote:

BigJ wrote:

KurtVerbose wrote:

ric355 wrote:

There are gains to be had, but by comparison with a turbo diesel engine they will always be smaller percentage wise. This is because it's easy to increase the amount of air that can flow into the cylinders on the TD by increasing the turbo boost pressure. Then just add the right amount of fuel to retain the correct mixture and you get a bigger bang.

Most, if not all, chipping companies aren't increasing the boost pressure. They're just burning air that's already there. They just get closer to the edge of complete combustion than the manufactures go.

Sorry I call b0llocks on this one. I own my own tuning company and I certainly raise boost pressure with a large amount of other maps.

I remapped my 4.4 M62 engine and it responded very well. The new owner had a 02 4.4 V8 and he noticed the difference as soon as he jumped into mine.

So what are your expected gains then on the 4.4 V8? I am more interested on mpg but extra power is always welcomed

Hi Matt, 12-15bhp max, but it's the way it drives and comes onto the power works better I found. The accelerator pedal does feel as if it has a huge amount of travel.

MPG you will not notice anything on the V8, best way is to LPG it. Mine was.

THe gains arn't as huge as in the TD6, TDV8 etc, but welcomed. It picks up better and has more midrange power.