Remap 35i
- Thread starter Timdon
- Start date
Remap risks voiding warranty of any part that could be affected by ECU alterations. (Turbos, main engine components, transmission etc). Bmw have to prove it and you may need to battle them otherwise.
Stage 1 gains are circa 50hp and are reportedly safe. Issues can arise at stage 2 which is circa 400hp. Down pipes and other alterations are required at stage 3 which is circa 440hp
Stage 1 gains are circa 50hp and are reportedly safe. Issues can arise at stage 2 which is circa 400hp. Down pipes and other alterations are required at stage 3 which is circa 440hp
I know DMS reckon 360-370bhp from a 35i ... which would be rather amusing. The downside is that BMW are likely to be able to find out fairly easily these days and then your warranty is screwed. I for one would not take the chance whilst under warranty. I used DMS to remap my E92 LCI 330d from 245bhp to 305bhp once it was out of warranty and it was fine - it flew in fact :evil: I just wouldn't do it on a car in warranty.
matsmith749
Active member
Yup - agree regards the power.
The 35is has a bit more power than it can cope with as it stands - if you up the power on a standard 35i to that kind of level (or more) then you will struggle to get anything from it rather than bragging rights.
Traction & suspension is the first thing I would look to improve before worrying about adding more power.
In order I would go tyres first, then a LSD, then more power.
Matt
The 35is has a bit more power than it can cope with as it stands - if you up the power on a standard 35i to that kind of level (or more) then you will struggle to get anything from it rather than bragging rights.
Traction & suspension is the first thing I would look to improve before worrying about adding more power.
In order I would go tyres first, then a LSD, then more power.
Matt
The JB4 is not ideal. It will butcher your transmission as it's just a cheap piggy-back unit that fools the engine into running higher load. It also needs to be fully removed before dealership visits or you run the risk of them finding it.
With regards to 400bhp being too much for the car. I really don't understand that point of view.
The chassis itself is well sorted and with some decent tyres there's no problems putting the power to the road. If your definition of too much power is being able to spin the wheels from a standing start then that applies to pretty much any car with more than 100bhp.
The point of adding more power is to give the car more grunt at speeds where traction is not so much an issue (above 30mph).
With regards to 400bhp being too much for the car. I really don't understand that point of view.
The chassis itself is well sorted and with some decent tyres there's no problems putting the power to the road. If your definition of too much power is being able to spin the wheels from a standing start then that applies to pretty much any car with more than 100bhp.
The point of adding more power is to give the car more grunt at speeds where traction is not so much an issue (above 30mph).
matsmith749
Active member
Too much power?
I guess what I mean is that the car feels unsettled when really pushing it - of course it struggles on a standing start, but it's not just wheel spin.
It squirms when accelerating hard at any speed to be honest, and is easily unsettled.
Hard to get over when typing stuff on a forum, but easy to feel. I've driven a normal 35i & it is not as bad when pushing on (obviously you can't push on as hard due to less power in a 35i), and I've also driven a 35is that was slightly tuned but had a quaiffe LSD fitted & sticky tyres.
The LSD / tyre combo made the car a lot less twichy when being aggressive.... better standing start... better cornering at speed - just more 'pointy' without feeling dangerous.
So what I meant was (ridiculous 100hp comment aside) that I think the adding of power in this case just adds to the negatives of driving the car fast IMHO & I would address other things first if I wanted more speed from the car.
I've had a lot of cars with big power & kept the 35is for longer than most - I really like the car, but it's not the best handler out there by a long way & if I really wanted it to be a more effective A-B missile it would definitely be tyres / LSD first (tyres done / LSD thinking about it).
If you read any review / look at any forum where people really push the cars hard you will see the same message over & over - it's not just my opinion.
I think they pushed the limit upping the power on the 35is & it really cries out for a LSD to be able to get the power down. Yeh you have standing starts where you can always be spinning tyres if you are a loon (not me), but any road conditions below 10 degrees & you lost traction under any hard acceleration. Damp road? Forget it. Even summer days with slightly poor road surfaces & you are driving with a feather foot.
But hey - of course I love power.... but prefer to be able to get it down.
Matt
I guess what I mean is that the car feels unsettled when really pushing it - of course it struggles on a standing start, but it's not just wheel spin.
It squirms when accelerating hard at any speed to be honest, and is easily unsettled.
Hard to get over when typing stuff on a forum, but easy to feel. I've driven a normal 35i & it is not as bad when pushing on (obviously you can't push on as hard due to less power in a 35i), and I've also driven a 35is that was slightly tuned but had a quaiffe LSD fitted & sticky tyres.
The LSD / tyre combo made the car a lot less twichy when being aggressive.... better standing start... better cornering at speed - just more 'pointy' without feeling dangerous.
So what I meant was (ridiculous 100hp comment aside) that I think the adding of power in this case just adds to the negatives of driving the car fast IMHO & I would address other things first if I wanted more speed from the car.
I've had a lot of cars with big power & kept the 35is for longer than most - I really like the car, but it's not the best handler out there by a long way & if I really wanted it to be a more effective A-B missile it would definitely be tyres / LSD first (tyres done / LSD thinking about it).
If you read any review / look at any forum where people really push the cars hard you will see the same message over & over - it's not just my opinion.
I think they pushed the limit upping the power on the 35is & it really cries out for a LSD to be able to get the power down. Yeh you have standing starts where you can always be spinning tyres if you are a loon (not me), but any road conditions below 10 degrees & you lost traction under any hard acceleration. Damp road? Forget it. Even summer days with slightly poor road surfaces & you are driving with a feather foot.
But hey - of course I love power.... but prefer to be able to get it down.
Matt
The problem there is purely the tyres. The car will be twitchy on OEM tyres because they have dismal traction and seem to really suffer on rough road surfaces even at high speeds.
I had the same Bridgestone run flat tyres on my 320d and even that thing struggled for grip until you were out of 2nd gear.
I had the same Bridgestone run flat tyres on my 320d and even that thing struggled for grip until you were out of 2nd gear.
matsmith749
Active member
I wish it was just the tyres.
I changed them to Pilot Super Sports after a few weeks of frustration with the run flats. They are definitely a lot better (hence my recommendation as STEP 1), but there is a way to go.
I'm not sure which model z4 you have experience with, but got to guess from your comments that it probably isn't an upgraded 35i / or a 35is.
This isn't a bash - I love the overall ownership experience of the car - but it has faults.
Matt
I changed them to Pilot Super Sports after a few weeks of frustration with the run flats. They are definitely a lot better (hence my recommendation as STEP 1), but there is a way to go.
I'm not sure which model z4 you have experience with, but got to guess from your comments that it probably isn't an upgraded 35i / or a 35is.
This isn't a bash - I love the overall ownership experience of the car - but it has faults.
Matt
It's a DCT 35i with a remap to approx 400bhp (stock hardware targeting 17PSI in the midrange and 15PSI further up). I have no problems with the extra power 
James: If you're worried about keeping the warranty the LSD will most certainly invalidate any cover on the gearbox. I think most LSDs will alter the final drive.
James: If you're worried about keeping the warranty the LSD will most certainly invalidate any cover on the gearbox. I think most LSDs will alter the final drive.
john-e89 said:
OP, sorry
Still on hols in 35iS ... still undecided ! It is going very well, which is good - and cheaper ! The dealer didn't come up with the goods £ wise on the M135i but still tempted. I may make him another offer but as there is now nothing wrong with the 35iS it is easier to keep.
I *may* order an M135i exactly as I want it rather than have the one the dealer has. His was black, which I would want, with privacy glass but had a sunroof and black leather. I would prefer no sunroof (as it's £900) and red leather. Time will tell ! The cheapest option is to keep the Z4. It is loosening up so nicely I would have to go through the process again with a new car and put up with 'moderate' performance for a few months which I may find frustrating.
Today the 35iS has gone rather nicely ... a trip through the Cheddar Gorge
matsmith749 said:
I don't agree. I think the 35iS could cope with another 25bhp but no more. It can squirm but I would agree more than +25bhp; i.e. 360bhp would be a chore to use. I love the fact it will deploy all the power all of the time in good conditions but think more than another 25bhp and it will struggle.
matsmith749
Active member
R.E92 said:It's a DCT 35i with a remap to approx 400bhp (stock hardware targeting 17PSI in the midrange and 15PSI further up). I have no problems with the extra power
James: If you're worried about keeping the warranty the LSD will most certainly invalidate any cover on the gearbox. I think most LSDs will alter the final drive.
That's really interesting - did you change anything else or just go with more power on it's own?
At first I thought it must be a faulty 35is (mine) - but drove half a dozen now & they have all been the same under power... weird. I see the issues that have been reported by just about every tester who had driven the car anywhere near the limit.... twitchy unpredictable swifts in the chassis / poor traction (at speed)... gearshift lurch upsetting the chassis under max load.... cornering lurch at speed... the lot. at it's worst it's like the front end of the car isn't connected to back end - press on hard & it tries to kill you.
Same road - same day - same speeds in a e92 m3 & no issue or drama.
You must have the 'good one'
My experience is that the stock car feels unstable when driven aggressively (only reason for more power surely is to drive aggressively?)... ah well... each to their own
Matt