I know i am posting this on compleatly the wrong website but i was hoping some of you guys on here may be able to shed some light on this problem. When my brother sold his Vrs (to me) he purchesed a BMW 123d m sport. If some of you are not aware it has a 2 litre twin turbo diesel engine with 204bhp as standard. Having now had this chipped by Tunit it ran fine but not with much bhp or torque gain. He then took it back up to get what they call laptop tuned which they basicly play about with the settings in the chip by increasing and decreasing the settings to achieve more power. Now tunit have told us they have had a 123d in befor for a laptop tune and it produced around 270bhp on their dyno. They managed to get 255bhp out of my brothers on the day on their dyno which he was pritty pleased with but when he took it out on the road in 4th gear at 4000rpm it all of a sudden looses power and if you take your foot off and put it back on it revs right through to the redline, or if you slowly feed the throttle in at around the 4000rpm mark you just get a slight judder then it runs through fine again. However in 3rd gear you can keep your foot flat and you get the slight judder then after 4000 rpm it doesnt seem to want to pull very well kind of like its hesitating. It only seems to mostly do it in 4th gear tho which i find hard to understand. It has had 3 different tunit chips on it and all 3 did the same thing so its not some sort of fault with the chip its self. The guys at Tunit are compleatly baffled by it and cant figure out what the problem is. The only thing i can think of is that its either overboosting some how or that the intake temp is geting to high but then it doesnt do it in 5th gear so i cant see it being that! Anybody got any ideas what this problem could possibly be???

Any help would be much appreciated!!

Many thanks!

Get someone else to remap it. Sounds like they've no idea what they're doing. Has it been rolling road tested with this map fitted?

With something of this value, and twin turbos, I'd want someone who knew what they were doing to look at it. Whereabouts in the country are you - why do people not fill in any location information in their profile??

I think Tunit supply a "box of electronics" along the lines of the Dragon Boxes.

I assume the laptop tuning is programming something inside the box.

Awesome were agents for them at one point - don't know if they still are - but maybe Sarah can help

I'd have gone for a proper remap not a tunit box or whoever they are... like has been said before, an expensive bit of kit to go wrong!

is it not your flywheel making the juddering noise as to much torque running through it?, as i work at a bmw main dealer and we have been getting customers complaining of clutch slip, with standard map's, we reprogram the dde to resolve this

Take it to a reputable tuner FFS!!!

I wouldn't dream of risking causing god knows how much damage to a very expensive car to fix. All for the sake of saving a few quid when getting it remapped on the cheap. Tuners like Mr Washbrook cost more than someone like Tunit for a reason - because they are the best.

Did you do any in depth research into Tunit before putting the car in other than taking their word for what they have done in the past to another 123d???

The only way I can put it to you is would you buy a cheap tyre that you have never heard of before (with no real reputation amongst enthusiasts) and expect it to hold you to the road in any conditions? Or would you choose an expensive Goodyear, Pirelli, Falken...etc. instead, that you know will do the job and is highly rated amongst enthusiasts as they have used it and it has proven to do the job?

I'm not trying to be smart or condescending in any way here either, it just baffles me when I read things like this.

Agree with the other lads, take it to a decent company, P-Torque, Shark etc and get it re-remapped there.

It does sound like an overboosting problem. The flywheels would be more likely to shudder at low revs, not 4k.

If it is indeed a tuning box solution, I shudder to think what effect that's having on the ECU and a sequential turbo setup! :'(

Steve

I know i am posting this on compleatly the wrong website but i was hoping some of you guys on here may be able to shed some light on this problem. When my brother sold his Vrs (to me) he purchesed a BMW 123d m sport. If some of you are not aware it has a 2 litre twin turbo diesel engine with 204bhp as standard. Having now had this chipped by Tunit it ran fine but not with much bhp or torque gain. He then took it back up to get what they call laptop tuned which they basicly play about with the settings in the chip by increasing and decreasing the settings to achieve more power. Now tunit have told us they have had a 123d in befor for a laptop tune and it produced around 270bhp on their dyno. They managed to get 255bhp out of my brothers on the day on their dyno which he was pritty pleased with but when he took it out on the road in 4th gear at 4000rpm it all of a sudden looses power and if you take your foot off and put it back on it revs right through to the redline, or if you slowly feed the throttle in at around the 4000rpm mark you just get a slight judder then it runs through fine again. However in 3rd gear you can keep your foot flat and you get the slight judder then after 4000 rpm it doesnt seem to want to pull very well kind of like its hesitating. It only seems to mostly do it in 4th gear tho which i find hard to understand. It has had 3 different tunit chips on it and all 3 did the same thing so its not some sort of fault with the chip its self. The guys at Tunit are compleatly baffled by it and cant figure out what the problem is. The only thing i can think of is that its either overboosting some how or that the intake temp is geting to high but then it doesnt do it in 5th gear so i cant see it being that! Anybody got any ideas what this problem could possibly be???

Any help would be much appreciated!!

Many thanks!

There is 100% no way they have got that engine producing 270hp. We see 250hp and 350lbs/ft torque with many map alterations and adjustments.

We tune this engine for racing in the Dunlop Maxx series and know it very well.

I have said it many times on the BMW forums, tuning boxes are no good on the later diesels equipped with DPF's.

Take it to a reputable tuner FFS!!!

I wouldn't dream of risking causing god knows how much damage to a very expensive car to fix. All for the sake of saving a few quid when getting it remapped on the cheap. Tuners like Mr Washbrook cost more than someone like Tunit for a reason - because they are the best.

oi! We are not that expensive you know :no:

Stackie, where are you based, there are probably several local tuners who could help out more?