[tacocat135]

Anyone with an LCI M550i running Racechip? If so, what are your thoughts? Worth it?

Seems like the safest option besides JB4/Dinan although I haven't seen many JB4/Dinan users on the LCI either. I really enjoyed using JB4 on my 440i but doesnt look like theres much support for the TU3 engine.

[Boosted_8]

I went through the same selection process as yourself last month. I opted for a jb4 in the end. The rationale being I'm pretty technical on the software side and wanted to be able to log and customise further. The install was harder with a jb4 as there is zero documentation, I was on my own with a right hand drive LCI figuring it out!

[AmooManiak]

I had it on my X5 M50i, which is a very similar platform in a much heavier car and it made a noticable difference. This was backed up by the dragy - gained 0.3 sec to 60 and in the 1/4. I had the JB4 in a different car before but did not want to route all the cables to the OBD2. Racechip was good enough and they actually have a warranty.

If I really wanted to get into the JB4 side of things with all the adjustments, I would just wait for a real flash tune.

[speedyman]

Originally Posted by AmooManiak

I had it on my X5 M50i, which is a very similar platform in a much heavier car and it made a noticable difference. This was backed up by the dragy - gained 0.3 sec to 60 and in the 1/4. I had the JB4 in a different car before but did not want to route all the cables to the OBD2. Racechip was good enough and they actually have a warranty.

If I really wanted to get into the JB4 side of things with all the adjustments, I would just wait for a real flash tune.

3 tenths with the Race Chip is a very good gain indeed along with a strong 1/4 mile and nice 115 trap.
Would the JB4 connected to only the TMAP points(no EWG adapters yet) on a '21 M50i do any better?

[AmooManiak]

Originally Posted by speedyman

3 tenths with the Race Chip is a very good gain indeed along with a strong 1/4 mile and nice 115 trap.
Would the JB4 connected to only the TMAP points(no EWG adapters yet) on a '21 M50i do any better?

From what I was explained when I bought the Racechip, unless you fully use all the JB4 capabilities (plug it into the OBD2), it is the same as Racechip. It just increases constant boost across. Since I was not going to go through that, I just ordere Racechip due to the warranty just in case. I ended up returning the Racechip though since I got rid of the car within the return timeframe.

[speedyman]

Originally Posted by AmooManiak

From what I was explained when I bought the Racechip, unless you fully use all the JB4 capabilities (plug it into the OBD2), it is the same as Racechip. It just increases constant boost across. Since I was not going to go through that, I just ordere Racechip due to the warranty just in case. I ended up returning the Racechip though since I got rid of the car within the return timeframe.

So if I read you correctly here, the JB4 with OBD port cable routed under dash and connected would yield more power than the Race Chip?
Sorry for a dumb question but just trying to learn. I would not mind fishing the cable.

[AmooManiak]

Originally Posted by speedyman

So if I read you correctly here, the JB4 with OBD port cable routed under dash and connected would yield more power than the Race Chip?
Sorry for a dumb question but just trying to learn. I would not mind fishing the cable.

Correct, that's how it was explained to me. The slight power difference was honestly not worth it to me to be routing (and using up) the OBD2 port. I did it years ago when I had an F10 550i but would not want to keep taking it off when I go to the dealer or risk warranty issues. I think it also helps with other safety paremeters that the Racechip doesn't have as it constantly tracks the car.

I think when you start using E85 is when you start to see the real benefits of JB4. That's not something I was interested in anyway.

[Boosted_8]

What's the additive boost pressure increase of the racechip across the RPM range?

[speedyman]

Originally Posted by Boosted_8

What's the additive boost pressure increase of the racechip across the RPM range?

My understanding is 3 lbs which should be quite noticeable.

[Boosted_8]

That would make sense as it's one size fits all. Jb4 map 1 is 4lbs additive. I run that with 94 fuel okay. For anything less than 93 I wouldn't want to run more than 3 pounds extra.
Fair play to the Racechip team in Germany, they do proper R&D and video it for the public to see what they are buying. For reference their tuned M550i ran 100-200kph in 7.6

[Boosted_8]

This run was at 58f / 14c using map one on the Jb4. This car has an X pipe and BMC drop ins as well.

All other factors standardised and If you have the Octane: it looks like each lb of boost can be worth 0.4 seconds over the 100-200 bracket. This will of course diminish in returns as heat builds and the car pulls out timing.

[choppedliver]

Originally Posted by Boosted_8

This run was at 58f / 14c using map one on the Jb4. This car has an X pipe and BMC drop ins as well.

All other factors standardised and If you have the Octane: it looks like each lb of boost can be worth 0.4 seconds over the 100-200 bracket. This will of course diminish in returns as heat builds and the car pulls out timing.

That’s decent. 👍