I never got the chance to hear @675430VME car with the jb4 but I can attest that the Mach 5 downpipe paired with his (I think is a custom) SS exhaust sounds extremely good for an i4. So much so that I also bought the downpipe.
JB4 Thread for Lotus Emira AMG i4 (M139 Engine) – Tuning, Setup, Results & Support
- Thread starter ManuelB
- Start date
400HP US version. Power figures are at the wheels. Hub dyno. Supposedly a stingy dyno that.
If noise is not a concern for you, I would go for a well design SS straight pipe. Cheapest, lightest, and sounds really badass through out the whole rpm. Some of the new straight pipes come with modified valve control so NO CEL as well.
Stingy but more accurate
- Thread starter
- #46
Thanks for the feedback! Using JB4 PRO with the BT dongle installed at JB4?
The regular JB4 app and BT. Has anyone been using V3 Alpha?
Which pipes come with the modified valve control?
You can do both as straight pipe or with muffler, either way you need a valve controller to bypass CEL.
Hey sorry for the beginner’s question but can fitting the JB4 threaten the health of the engine? I’m not planning anything crazy, no ethanol or something, just trying to compensate for those 40bhp that we in the EU were stolen.
Anything that changes anything can potentially threaten the health of the engine. Not limited to adjustments in fuel trim and ignition timing, piggybacks will also introduce additional wiring, which means increased risk of melting wires or disconnecting couplers that can result in damage. Understanding how the unit fools the stock ECU, and taking care of the wiring (heat, abrasion, tension, etc.) should reduce the risks of damage, but will never bring it down to zero.
Most piggyback users consider these risks vs their own risk appetites to decide. I thought that the JB4 harness was reasonably protected, if kept away from hot surfaces. (The OBD2 cable is another story)
I will write a comprehensive dedicated post on the methanol installation but just to update here are some prelimary results, pending more tuning and final dyno/road testing.
My setup currently:
Aerie sports cat and exhaust
new JB4 BT module and the newer JB4 Pro app
Snow Performance methanol pump
Burger Motorsports nozzle spraying into Weistec charge pipe
Using pump 91 (California) on the dyno at DRS my car baselined around ~360whp which is around 10% drivetrain loss on their dyno which normally reads about 10-15% lower than crank (that's normal). That's with a downpipe/sports cat and Aerie exhaust...pure stock might read 350/55 or so on this dyno. Using map 7 on the JB4 running one nozzle and 50/50 spray and some tuning with Terry's help remotely we ended up with 407whp. Doing the crank hp calculation that's around +50hp on pump 91 gas...which is kind of crazy.
I am getting a couple pre and post cat rich codes, from the methanol coming on little too early in transient throttle around 3-4k rpms, so we are doing some more testing with different JB4 settings for the methanol controller. I did also try map 2 using 93 gas and that map also feels very strong, super smooth and did not generate any codes. Previously before the JB4 I was getting codes from the Aerie sportscat, first the normal P0420 and then after the spacer, the sensor was too far away. Map 2 on my particular car seems to be a sweet spot so far.
While on the methanol map 7 the car has a ton of torque and in the canyons which is what I use this car for, I am running out of brakes pretty quickly - will be changing to more aggressive pads at some point.
Terry has been very helpful and responsive. If you are just going to do standard JB4 install and run map 2 with access to 93 gas don't hesitate...car runs very fast, tons of additional torque down lower where you want it, and kind of manic top end power. Once we get a real ecu crack and can add what the euro AMG A45S guys are running this car will be even more of a weapon. Big thumbs up it works really well. I'll write a dedicated methanol installation post once we finalize everything and I get lots more miles and figure out the best settings. My IAT's were ~10 degrees from ambient after running hard for a couple hours with repeated pulls and was consistent, the methanol works really well.
Oh also last note, the logging feature of the JB4 is super helpful. You can download your logs and throw it into ChatGPT/Claude/whatever you use and it will give you highly accurate descriptions of what's going on, how well your car is handling heat, AFR's, how much timing, etc. REALLY helpful. My Emira GPT is very impressed with the logs from map 2 and map 7 and gave me a couple recommendations which Terry echoed as well.
My setup currently:
Aerie sports cat and exhaust
new JB4 BT module and the newer JB4 Pro app
Snow Performance methanol pump
Burger Motorsports nozzle spraying into Weistec charge pipe
Using pump 91 (California) on the dyno at DRS my car baselined around ~360whp which is around 10% drivetrain loss on their dyno which normally reads about 10-15% lower than crank (that's normal). That's with a downpipe/sports cat and Aerie exhaust...pure stock might read 350/55 or so on this dyno. Using map 7 on the JB4 running one nozzle and 50/50 spray and some tuning with Terry's help remotely we ended up with 407whp. Doing the crank hp calculation that's around +50hp on pump 91 gas...which is kind of crazy.
I am getting a couple pre and post cat rich codes, from the methanol coming on little too early in transient throttle around 3-4k rpms, so we are doing some more testing with different JB4 settings for the methanol controller. I did also try map 2 using 93 gas and that map also feels very strong, super smooth and did not generate any codes. Previously before the JB4 I was getting codes from the Aerie sportscat, first the normal P0420 and then after the spacer, the sensor was too far away. Map 2 on my particular car seems to be a sweet spot so far.
While on the methanol map 7 the car has a ton of torque and in the canyons which is what I use this car for, I am running out of brakes pretty quickly - will be changing to more aggressive pads at some point.
Terry has been very helpful and responsive. If you are just going to do standard JB4 install and run map 2 with access to 93 gas don't hesitate...car runs very fast, tons of additional torque down lower where you want it, and kind of manic top end power. Once we get a real ecu crack and can add what the euro AMG A45S guys are running this car will be even more of a weapon. Big thumbs up it works really well. I'll write a dedicated methanol installation post once we finalize everything and I get lots more miles and figure out the best settings. My IAT's were ~10 degrees from ambient after running hard for a couple hours with repeated pulls and was consistent, the methanol works really well.
Oh also last note, the logging feature of the JB4 is super helpful. You can download your logs and throw it into ChatGPT/Claude/whatever you use and it will give you highly accurate descriptions of what's going on, how well your car is handling heat, AFR's, how much timing, etc. REALLY helpful. My Emira GPT is very impressed with the logs from map 2 and map 7 and gave me a couple recommendations which Terry echoed as well.
I won’t be the one installing the JB4, since I’m a noob plus the i4 looks to be much trickier than the v6. This means I will not have control over how the job is done. If fitting the piggyback means accepting the risk to see my engine fail without doing fancy things by a high chance, say 10-15%, then it’s a pass for me. If, instead, this means that the risk is higher by 1-5%, then it might be ok. I know that no one can give me those numbers, it’s just to clarify that yes, it’s clear to me that it will take some risk with it, but the real matter would be “to quantify the actual risk in order to properly evaluate it”. This is given by experience, which I don’t have.
For those with jb4: what is the headspace on the stock fueling system? Would ethanol mixes seem acceptable with tuning?
Edit: and on that note, I'm assuming the jb4 can only send demand it cannot control the port injection system itself. (I.e. turn it on at lower rpm)
Edit: and on that note, I'm assuming the jb4 can only send demand it cannot control the port injection system itself. (I.e. turn it on at lower rpm)
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