Honestly never knew e85 was this addictive. Woke the sleeping giant in the motor when I added 60:40 of e85/93 pump on map 7. The fact that one can do so much with the user interface of the jb4 especially the ISO 5 version is just hard to beat.ĭid the BMS back end flash on it but with stock turbos on pump gas, the jb4 alone was still the best. The JB4 comes out of the box set to Map 1 which is 4 psi over stock boost levels. If you are looking to tune your car, will help you out!Ĭoming from a pair of bms down pipes and drop in panel filter only, it's hard to beat a Jb4 for the performance value wise, boost response is almost second to none not to mention the delta whp it produces on pump gas alone. Go to and you'll find the software you are looking for and info that may answer your questions. It's used in conjunction with the jb4 for users who are running high e85 mixes/octane or upgraded turbos. Just read through those threads and start learning what everyone's done.The BMS flash isn't really for stock cars. You could get all those parts for pretty cheap on the want to buy section. I didn't run map 7 until I had downpipes intercooler and charge pipe and race gas. I guess it's up to you if you want to listen to those suggestions or not. Home of the JB4 the worlds most popular turbocharged tuning system It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper. The auto tune will notice the downpipes and up the boost so you'll definitely be able to feel it and see it on the boost gauge. There will be a power increase with each map you increase to. However if the only change after doing the DP's is a faster spool and change in sound, then for me, it wouldn't be worth it. I don't need/want much more, but if for around $400 I can free up the exhaust restrictions and gain a little bit of easy power, then I feel it would be worth it. When the g5 board is installed the car runs with no O2 issues but. If I install the g4 board the car runs fine minus the O2 issues (reason for upgrade).

I have the wiring harness from the old jb4 but i dont know if i need modifications to it. The JB4's power increase is pretty amazing by itself. I am recently upgrading from a g4 jb4 to a g5 jb4. I guess my 'goal' is to squeeze out as much power as I can while still keeping it reliable and safe. Are the claims of an increase of 30hp (with certain maps) just not enough to feel? So I notice you didn't mention any perception of an increase in power. I think downpipes are totally worth if for sound and quick spool. All mods are only 'worth it' if there's a certain goal your trying to reach.

Jb4 g5 interface program