More power from a diesel without a remap

[Yugguy]

Hello all.

Been looking at remaps for the Merc. Turns out that I have the OM646EVO engine and not the OM651 that was fitted from 2010 on.

This is good in one sense as the 651 has timing chain issues where the 646 is said to be pretty bulletproof.

It does mean though that a remap only yields another 20bhp and 50Nm, not a huge amount. Plus I'm in two minds wether I want to, it is smooth and progressive at the moment and I don't want it to turn into something that just dumps torque and spins the wheels and puts more pressure on my turbo.

A remap would cost about £350 so instead of that, what could I spend that on to either increase power safely, OR in something like weight reduction? The biggest thing I can think of for weight reduction is the wheels and I'm not sure I want to change those.

 

[gladrags]

Personally I wouldn’t remap it – if you feel it’s smooth and progressive at the moment. I had my Audi A6 2.7 tdi remapped shortly after I got it from 177 to 200 bhp. Got it done through a friend of a friend by an Audi tech who did a full service as well, came in about £450 so not too bad.

I sometimes feel that it wasn’t necessary though. The engine has bags of torque now and the acceleration’s great but even in standard trim you can get that if you use the Sport button (Multronic box). Let’s face it you don’t use the maximum torque very often – well I don’t anyway and sometimes I feel as if I’m just tickling the accelerator. Don’t get me wrong, it’s smooth enough and tractable and all the rest of it and it started throughout the winter with no problems. I just wonder if it was really necessary.

I’d think about lighter alloy wheels if I was you or maybe upgraded brakes or even stereo.

 

[old-git]

Personally I wouldn’t remap it – if you feel it’s smooth and progressive at the moment. I had my Audi A6 2.7 tdi remapped shortly after I got it from 177 to 200 bhp. Got it done through a friend of a friend by an Audi tech who did a full service as well, came in about £450 so not too bad.

13% increase on a turbo diesel engine? That is very low, N/A petrol territory. Unless your engine is unusual, you should be looking at around 70bhp increase, taking it to over 240bhp. I reckon the 'Audi Tech' must have either put a very mild map in or didn't know what he was doing.

 

[Yugguy]

Depends on the existing tune I guess. My bora went from 130bhp to 170 and could have had 190 but nowhere could take my 115bhp Focus much past 140.

Om646 standard is 143 in the c200, mine is 170 so already a fair bit more.

 

[old-git]

If the Focus is petrol turbo then 140 is about right. 143 to 200 on a turbo diesel is, again, about right.

 

[HDi fun]

With car makers 'taking up the slack' and 2.0 diesels now reliably delivering around 200bhp in factory tune there is less room to remap than perhaps there was ten years ago.

 

[Aerial Andy944]

Just had my PD170 remapped. Everything is sharper but as for outright power the turbo runs out of puff at around 200hp along with the injectors so no way could anyone get more out of the engine even though it can probably take it. Biggest gain I could find was Celtic who claimed taking it to 214hp but Darkside Development, who only work with these engines, said its not possible even with DPF and exhaust system upgrades. Bigger Turbo and fueling system is the only way to make bigger increase

13% increase on a turbo diesel engine? That is very low, N/A petrol territory. Unless your engine is unusual, you should be looking at around 70bhp increase, taking it to over 240bhp. I reckon the 'Audi Tech' must have either put a very mild map in or didn't know what he was doing.

 

[gladrags]

13% increase on a turbo diesel engine? That is very low, N/A petrol territory. Unless your engine is unusual, you should be looking at around 70bhp increase, taking it to over 240bhp. I reckon the 'Audi Tech' must have either put a very mild map in or didn't know what he was doing.

Old Git I’m well aware of that a diesel engine can be remapped much higher than what I had mine done to, matter of fact the first figure that was offered was 240 bhp but I declined, I was more interested in mid range TQ eg if I’m on a slip road with a steep incline with 5 up and luggage on an airport run and I want to join fast moving traffic seamlessly then I want grunt.
The other thing that I wasn’t sure of was the Multronic transmission, I’ve heard a lot about the 7 plate clutches etc and didn’t want to start any trouble there. As it happens it’s been fine.

I have every faith in the Audi tech who worked on my car, he came recommended to me by people in the trade whom I know and trust implicitly. So your innuendo is a bit crass and completely uncalled for.

 

[Yugguy]

Ok let's leave the remap arguments!!!

What else can we do to either get more power or use the existing power better?

 

[HDi fun]

Not a lot really. Whatever you do is likely to require a remap anyway. Premium diesel fuel does help though.

 

[old-git]

I have every faith in the Audi tech who worked on my car, he came recommended to me by people in the trade whom I know and trust implicitly. So your innuendo is a bit crass and completely uncalled for.

I said "I reckon the 'Audi Tech' must have either put a very mild map in or didn't know what he was doing." So, I was right as he put in a mild map. It wasn't crass, it was an opinion that he either put in a mild map (which he did) or he didn't know what he was doing (which he did). Can't see the problem here.

As for innuendo, the definition of which is:

"an allusive or oblique remark or hint, typically a suggestive or disparaging one."

There was nothing allusive or oblique in my statement, as far as I can make out.

 

[gladrags]

No worries man, no offence impplied or taken. Talking about power you said yourself it's not just about power it's power to weight ratio. The Audi weighs close to two tonnes so still a slug by some measures.
Best thing I ever rode was a 500cc Speedway JAP. It belonged to a farmre's son that my son was friendly with. Wild 500 cc engine with 15:1 compression ratio and hairy cams running on dope fuel, Light alloy frame, no gearbox just a countershaft with a clutch and no brakes. The whole thing must have weighed about 5 kilos. It had a 60mph rear sprocket on it and i reckon it went to 60 in about 2 nanoseconds. One wild ride.