[RC Pilot]

I have a JB Stage 1 on my 2015 M235i and been itching for a little more power. It seems like the next step would be to get a downpipe and go with the JB4. But... 91 octane is all that is available in my area. E85 is also readily available.

Couple questions / concerns I have:

1) It seems like a PITA to swap out the DP. Something like 3-4 hours for DIY. My car is under warranty. About every 6 months I have to take it to the dealer for something (this week was cracked and blown out charge pipe). Here in CA I also have to do emissions testing. So I'd really prefer to avoid a DP unless it is a must to get beyond Stage 1 power.

2) There is E85 readily available here but I think BMW says not to run more than 10% ethanol.

3) Can I get a noticeable increase in power over what I get now with my Stage 1 with only 91 octane if I upgrade to a JB4 with no DP?

4) Can I get a noticeable increase in power over what I get now with my Stage 1 with only 91 octane if I upgrade to a JB4 and run E85? If so, will the E85 cause damage or warranty issues?

[Shayan55]

Originally Posted by RC Pilot

I have a JB Stage 1 on my 2015 M235i and been itching for a little more power. It seems like the next step would be to get a downpipe and go with the JB4. But... 91 octane is all that is available in my area. E85 is also readily available.

Couple questions / concerns I have:

1) It seems like a PITA to swap out the DP. Something like 3-4 hours for DIY. My car is under warranty. About every 6 months I have to take it to the dealer for something (this week was cracked and blown out charge pipe). Here in CA I also have to do emissions testing. So I'd really prefer to avoid a DP unless it is a must to get beyond Stage 1 power.

2) There is E85 readily available here but I think BMW says not to run more than 10% ethanol.

3) Can I get a noticeable increase in power over what I get now with my Stage 1 with only 91 octane if I upgrade to a JB4 with no DP?

4) Can I get a noticeable increase in power over what I get now with my Stage 1 with only 91 octane if I upgrade to a JB4 and run E85? If so, will the E85 cause damage or warranty issues?

You can run stage 2 (bm3) with 91. But you would need a downpipe

[RC Pilot]

I found a JB4 vs Stage 1 comparison thread on the F30 Bimmerpost forum that answered my questions. Without a DP, the Stage 1 or JB4 Map 1 is all you can do on stock car. Also to get any e85 benefit need to go to JB4 map 2 and that also requires a DP. Seems odd that the stock DP is so restrictive. Does the M2 use a different DP to allow for the extra power?

This must be what happens to drug addicts. You get used to the extra HP and "need" more and more to keep you happy. LOL. I actually thought my Stage 1 was defective after a few months because it didn't seem like it was doing anything. Then I took it off the car to have the car serviced and the car felt like a dog without it. Leaving it off for a couple of extra days this time to get used to the stock car feeling again so when I plug the Stage 1 back in I will enjoy the extra HP even more.

[Anthony235]

Originally Posted by RC Pilot

I have a JB Stage 1 on my 2015 M235i and been itching for a little more power. It seems like the next step would be to get a downpipe and go with the JB4. But... 91 octane is all that is available in my area. E85 is also readily available.

Couple questions / concerns I have:

1) It seems like a PITA to swap out the DP. Something like 3-4 hours for DIY. My car is under warranty. About every 6 months I have to take it to the dealer for something (this week was cracked and blown out charge pipe). Here in CA I also have to do emissions testing. So I'd really prefer to avoid a DP unless it is a must to get beyond Stage 1 power.

2) There is E85 readily available here but I think BMW says not to run more than 10% ethanol.

3) Can I get a noticeable increase in power over what I get now with my Stage 1 with only 91 octane if I upgrade to a JB4 with no DP?

4) Can I get a noticeable increase in power over what I get now with my Stage 1 with only 91 octane if I upgrade to a JB4 and run E85? If so, will the E85 cause damage or warranty issues?

1) I believe here in Cali emission testing is only after the car is 7 years old. Then every 2 years after that. I've never owned a car longer than 2 years so I'm not 100% sure. But it's at least 5 years. I personally would not go beyond stage 1 power without a DP since it shorten the life span of your cat...which is expensive. By how much depends on how hard you drive the car (heating up the cat). You will want an aftermarket charge pipe ASAP.

2) http://www.2addicts.com/forums/showthread.php?t=1450565

3) I don't believe you will get a big boost in power from just going from stage 1 to JB4. Without a DP you will be on JB4 map 1 which probably isn't much more aggressive than stage 1. You should verify though as I'm not to familiar with stage 1. JB4 will allow you to do a custom map 6 for 91oct though which should get you more power over stage 1, but it seems you're not familiar enough about tuning to do it (no offense).

4) Yes, but not without a DP. ~50hp increase with E30 and DP.

[RC Pilot]

Thanks for the additional info. If the emissions testing is not for 5 years that makes the DP more desirable for me. I think I only have about 15K miles until my warranty is up. I could live with swapping out the DP every couple of years for emissions testing. When the warranty is up there should still be about 2 years until testing needed. I love this car but would like a bit more HP beyond the Stage 1. But I have to say the Stage 1 for $400 and super easy 5 minute installation is the best bang for the buck for anything I've ever done to a car.

[Anthony235]

Originally Posted by RC Pilot

Thanks for the additional info. If the emissions testing is not for 5 years that makes the DP more desirable for me. I think I only have about 15K miles until my warranty is up. I could live with swapping out the DP every couple of years for emissions testing. When the warranty is up there should still be about 2 years until testing needed. I love this car but would like a bit more HP beyond the Stage 1. But I have to say the Stage 1 for $400 and super easy 5 minute installation is the best bang for the buck for anything I've ever done to a car.

Wait, I think I confused myself.

In my reply to you I'm talking about going from JB+ to full JB4.

[mike@x-ph.com]

JB4 will net you more power either way.

You can also get an intercooler and/or meth injection

[M235SDCA]

In CA they don’t really test the cars any more. They do a visual inspection and check for fault codes. Basically no CEL, no really obvious mods, no problem. Brought my old 330 in with Dinan mods - shop checked CEL, noticed the mods but didn’t feel like looking up CARB info even though it was OK.

Emissions test places only get like $40 to do the test so they are not going to spend a lot of time looking. Time frame from new to first inspection is 6 years in CA.

[Jeff@TopGearSolutions]

2-3 gallons of E85, JB4 tune and FMIC would yield considerable gains while retaining stock downpipes and it shouldn't really red flag too many dealers.