35is and JB4
- Thread starter JamesUK
- Start date
mcbutler said:
It's not really as clear cut as that. Keeping intake temps low helps prevent pre-ignition and increases the charge density so will boost power slightly. Ideally you want to keep intake air temps below 50C, the stock intercooler will do that fine at power levels under 400bhp.
I upgraded my intercooler and downpipes to get the most out of my stock turbochargers but before that I was happily running around the 400 mark with the stock intercooler with healthy charge temps. That's one of the perks of the UK climate.
The truth is that most UK based tuners are quite limited when it comes to single platform expertise and have a standard list of excuses to reel out to customers to convince them to spend their money. The bulk of them use generic maps which just modify a limited number of parameters in the stock software. They will have a tool that's capable of writing to the ECU on many cars and have a collection of generic tunes to apply to them, that's the standard business model of all these tuning shops offering £400~ remaps, Celtic are no different.
The generic files that they write to cars are actually freely available on the internet, these map packs all offer an easy bump in performance but leave a lot of power on the table. Those shops often have a dyno to give the impression that they actually do some R&D but in reality it's just there for the printout to keep the customer satisfied.
Currently MHD is the only tool capable of writing custom logic to the ECU so unless the likes of Celtic start using MHD and customising their own tunes they will always be trailing.
I agree with most of what you say, regarding research my point of focus was on US tuners who work mainly with the N54, although as you say, climate is obviously an issue.R.E92 said:
The intercooler linked to earlier is an absolute bargain, might be worth trying to get a group purchase together on that?
Celtic would be pretty unhappy with you including them in the 'downloading maps' genre of tuners. They develop and write their own maps in house (which is probably why they can offer a 12 month guarantee against mechanical damage) and have a software suite & several research vehicles on the premises they are currently working on. They were the first to write a map for the 61 plate model C63 of which I had one.
I use them exclusively, there premises are state of the art and I have total faith in them.
I got my local tuning shop to add VRSF downpipes that l bought from ML performance and tune the car. It returned 385BHP & 450 lb of torque on the dyno. 2 years later l wanted a bit more, I fitted BMS DCI and a cheaper bigger FMIC from ebay. Bought MHD flasher and stage 2+ map (which was a complete Bastard to install due to Google play), tuning the exhaust is great fun. End result fantastic, l am very happy with the car for now, above 3000 revs it's absolutely balistic , below that it's 26mpg, do it! My car is a 35i 2009 38k.
TurboSnail
Member
I have a MHD stage 1+ tune and a Wagner intercooler on my 35is. Running on 100 octane it has 417 hp and 609 nm with no issues so far. Had the Z on the dyno a couple of times (at different garages) and the power delivery is very consistent. As a bonus, it also gets better fuel economy 
MHD is also easy to use and offers other useful options as well. Only issue was that I had to buy an Android device
MHD is also easy to use and offers other useful options as well. Only issue was that I had to buy an Android device
Most reputable tuners would recommend a stage 1 (365 BHP - 400 LB/Ft) as the limit on stock components, even then an intercooler upgrade is recommended if you want to keep your turbos healthy.
I know Celtic guarantee your car against remap related damage but only cover up to stage 1 which speaks volumes really.
The N54 is one, if not the most, tuneable (is that a word?) engine BMW have produced but not the most reliable, the more you boost its output the shorter its lifespan, obviously.
My 35i is stage 1, got an intercooler on the way. The car is fast but still driveable on the twistys as opposed to a straight line missile, just need to get the bloody awful potenza tyres swapped for Pilot Sport 4S and it'll be brill
I know Celtic guarantee your car against remap related damage but only cover up to stage 1 which speaks volumes really.
The N54 is one, if not the most, tuneable (is that a word?) engine BMW have produced but not the most reliable, the more you boost its output the shorter its lifespan, obviously.
My 35i is stage 1, got an intercooler on the way. The car is fast but still driveable on the twistys as opposed to a straight line missile, just need to get the bloody awful potenza tyres swapped for Pilot Sport 4S and it'll be brill
mcbutler said:
Provided your IAT's are in check and your components are healthy there is no reason why you can not go above 365bhp. Stage 2+ which is 420bhp on MHD is a very conservative tune for the N54. The stock turbos approach their limit around circa 450bhp on 99 ron fuel, you can go higher with ethanol mixes / meth injection. The N54 its self is reliable, it is everything around it which is not lol.
Particularly injectors, HPFP, Turbo wastegates, Valve Cover spring to mind. Mods like an intercooler, downpipes etc will reduce IAT's, restriction, and stress on the turbos, if anything it could potentially increase the life of certain components.
A
Anonymous
Guest
mcbutler said:
Transmission Model Engine/torque Transmittable torque rating
GS7D36SG E90 M3 E92 M3 E93 M3 400 Nm 520 Nm
The 36 stands for 360 ft lb which is the marketing torque limit
Most sources cite 520nm as the limit
Interesting that's the output shaft torque limit at 400nm input shaft
So the box is spec'd for the 35i constant max torque not the 35is boost torque number..
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Anonymous
Guest
mcbutler said:
Its difficult to know..
On the one hand there are many people running boosted cars with these boxes without documented effects..
On the other people sell stronger clutch packs for them..
IMHO, British Leyland excepted (where I witnessed some true muppetry), most German companies would massively underate their products to avoid marginal warranty claims..
The manual box is alleged to be much stronger than the DSG for those going for serious OD on BHP on the 35i
Personally if the car was a keeper, and I pressed the go pedal to the bottom a lot I wouldn't go much more than 600nm max which is just a tad above the celtic type re-maps..