[410BN]

I'm new to the N54 scene (as of today - picked up an 07 335i ). The car was FBO + RB turbos, but before I bought it, the seller took it back to stock except for the JB4 and the RBs. Can the JB4 on MAP 5 safely handle a stock car with RB turbos? Ideally, I know it is recommend to have the BMS back end flash, and I'll be getting that pretty soon. Until then, safe or no?

Thanks for the input.

[idrift4wd]

YES.

[410BN]

Thanks for the quick response! Now I need to decide what's next.. Intercooler or DPs!

[Kenu8187]

Intercooler IMO

[Brule]

log and see.

I am FBO with RB's and its fine to run map 5.

[Bme30]

Originally Posted by 410BN

Thanks for the quick response! Now I need to decide what's next.. Intercooler or DPs!

Both!!!! Lol

[410BN]

What do you guys think would keep under hood temperatures down more? It's a non sport model so no oil cooler unfortunately. Oil temperature hasn't gotten real hot but it did get up to 245 or so when I was playing around a bit yesterday.

[tjobeid]

who takes off everything and keeps RB's lol, old owner was a cheap A$$

[Surquhar]

On a stock car I would say IC first, but with the RB's you have to get DP's first. You need to let them flow. Back pressure is bad for them. IMHO

[lfelunden]

You need downpipes! RBs and stock dp is a waste lol

[Dmacc]

Intercooler and dp are absolutely necessary for RB turbos, get both!

[evo335xi]

DP's because the turbos are more efficient than stock and the car won't heatsoak as quickly. IC definitely after though when you get a tune and raise boost.

[410BN]

Ideally I'd like to put an intercooler and DPs on at the same time but I'm not sure if I'll have the extra funds for both at once. If I have to do one first, I'll go for the DPs. Does anyone have any rwhp estimates for an RB turbo/DCI/JB4 Map 5/93 octane setup? Probably not too many setups like mine out there lol

[410BN]

I did a few 3rd gear 40 mph - 100 mph pulls last night. I've attached the 3rd pull to this post. Is it normal for the boost to steadily drop like that after 5,500 on Map 5? Also, the AFR seemed a little lean to me but I don't know what these cars like. I wonder if Map 1 would be better for me.

Only mods are JB4 and RB turbos, currently. I have a charge pipe, BOVs and DCI that i'll probably get on there this week.

[Cloud9blue]

You can get away with DP and intercooler if you are ok with keep the boost under 14 psi... But again what's the point of having these upgraded turbo anyway???

Get an intercooler first, so you can unlock the top end power that RB turbo are suppose to provide. If you want more power after that, a set of DPs will let to turn up the boost up to 17-18 psi. Just make sure you are running 93 gas at the very least, maybe even throw in 3-5 gallons of e85 just to prevent any knock.

[Cloud9blue]

Originally Posted by 410BN

I did a few 3rd gear 40 mph - 100 mph pulls last night. I've attached the 3rd pull to this post. Is it normal for the boost to steadily drop like that after 5,500 on Map 5? Also, the AFR seemed a little lean to me but I don't know what these cars like. I wonder if Map 1 would be better for me.

Only mods are JB4 and RB turbos, currently. I have a charge pipe, BOVs and DCI that i'll probably get on there this week.

Is your ECU software stock? The ignition advance seems to be pretty high, and that's why your engine is pulling ignition in the mid range (look for the sudden drops in timing). AFR is slight lean, but what's your IAT?

[410BN]

Now that you mention it, I think I do remember seeing some paperwork from the dealer saying that it had a "performance flash" done a few years back. I do know that the BMS backend flash was previously done and removed, I don't know if that would have any effect on the flash done by the dealership.

The IAT was 86 when I started the pull at 3,000 RPM. It got up to 111 by the time I let off at about 6,700 RPM.

[Cloud9blue]

Originally Posted by 410BN

Now that you mention it, I think I do remember seeing some paperwork from the dealer saying that it had a "performance flash" done a few years back. I do know that the BMS backend flash was previously done and removed, I don't know if that would have any effect on the flash done by the dealership.

The IAT was 86 when I started the pull at 3,000 RPM. It got up to 111 by the time I let off at about 6,700 RPM.

111 is not too bad. But I suggest you find out if the ECU software has been modified at all. If you are not comfortable with scanning and flashing your own car, try contact Wedge (http://www.e90post.com/forums/member.php?u=135663). He seems to be the go-to guy for flashing n54 engines.

[410BN]

Thanks for the suggestion. IF the ECU software has been modified by BMW, do you suggest taking it back to stock? I plan to do the BMS back end flash with the BT cable, will that override the performance software that was installed by BMW?

[DuDai]

Originally Posted by 410BN

Thanks for the suggestion. IF the ECU software has been modified by BMW, do you suggest taking it back to stock? I plan to do the BMS back end flash with the BT cable, will that override the performance software that was installed by BMW?

I never did. Most of these flashes will be able to recognize that kind of flash, like if it were a dinan flash, and they be able to overwrite it and be able to replace it with a stock type flash, but not a dinan flash.

[Cloud9blue]

Originally Posted by DuDai

I never did. Most of these flashes will be able to recognize that kind of flash, like if it were a dinan flash, and they be able to overwrite it and be able to replace it with a stock type flash, but not a dinan flash.

I suggest you save your current ECU map, and have it analyzed by someone who knows what's going (Wedge or ProTuning Freaks) to determine if it is suitable for the setup you are going for. The problem is that your car was heavily modified before, and the previous owner only did a half ass job of returning to stock, leaving you with no idea what map he has in there. I highly doubt he was just running a BMW performance flash, considering he has got RB turbos.