Stage 1+ MHD flash on stock 35is

[distinctperson]

For my previous 35i and 35is (yes, I had 2 before that I ended up totaling), I have only used ESS tune. Tired of paying another $700 for a cable and license that will be useless if I lose the car again, I decided to purchase the MHD flasher module and stage 1 maps.

The question is, will it cause any harm to install stage 1+ (as opposed to stage 1 that requires no modifications) on my stock 35is ? The app states that upgraded FMIC is recommended for this tune, but I don't obviously have it upgraded yet. I know with a 35i this will be an easy decision as they come with no intercooler at all, but with the stock 35is intercooler, will it be OK to flash Stage 1+ ?

I just finished flashing it, and turned it on to make sure it runs but didn't drive it at all. Will test drive it in the morning and compare it against ESS tune that I've had in the past.

Your input is appreciated!

[NoQuarter]

All N54 engines come with an Intercooler - your 35i had one I guarantee it.


Now for your question.... An intercooler cools the charge air back down before it goes into your engine. A bigger intercooler serves to cool it down a bit more and resists getting heat soaked some more which in turn makes it more difficult to cool the charge air down.

All that is to say.... if you are not racing your car around attempting to crash this one too then don't worry about the charge air temp - you won't know the difference.

And I will say.... you of all people seem the least likely person that should be adding power to a 35is. Learn to drive what you have safely before you hurt someone and not just your cars.

[jts1981]

Originally Posted by NoQuarter

All that is to say.... if you are not racing your car around attempting to crash this one too then don't worry about the charge air temp - you won't know the difference.

And I will say.... you of all people seem the least likely person that should be adding power to a 35is. Learn to drive what you have safely before you hurt someone and not just your cars.

I have to disagree with running stage 1 + w/o intercooler upgrade. The oem unit performs very poorly, even on stock tune. Adding more boost will only lead to limp mode, and a ton of misfire codes.

BUT I do agree with you bout OP not needing more power. High performance driving school would be the better investment...

[ljkiter]

Agree.
I'm going to do the MHD tune after I do a little autocrossing

[Constant.S]

You can run stage 1+ with stock intercooler but its not healthy for you engine on consistent pulls and especially when the weather warms up. Try it on your own risk

[distinctperson]

I must begin by thanking both of NoQuarter and jts1981 for their apt parental advice

Aside from that, I drove the car today and was satisfied with the performance, which, so far, mirrors the performance of ESS tune exactly. And given that the temps are pretty low in NorCal rightnow, the temp needle never crossed the middle even after pulling hard a few times and redlining it. But I do understand the threat here. I'm just too lazy to have to deal with the downtime associated an FMIC upgrade, but will do so sometime in the spring.

[mrkoven]

an fmic upgrade is well worth it! i also added dp soon after. really enjoy the performance on my mhd stage 2+, and recent crispy norcal temps too!

[distinctperson]

Just a quick update, although I feel this is worthy of a new thread entirely. After driving the car for a while, the performance scaled up significantly under the Stage 1+ MHD map, overshadowing the earlier performance of ESS tune that I had in my previous E89s.

I am very glad that I did not spend another $700 and went with the cheaper alternative that produced better results, and that allows for further customization through the app. Oh, and I did manage to get the needle to cross the middle just a bit, but that was the same with the ESS tune --- so no difference in temps so far between the tunes.

[NoQuarter]

Thanks for being a good sport on the parental advice!

If you are just having some fun on the on-ramps and such don't worry about the intercooler too much. But just as jts1981 said, if you go too far your intake temps will get much too high.

You can use MHD to monitor and log all the important stuff. If you were to do a long hard pull you will see the IAT skyrocket very quickly.