JB4 Pushing Boost Limits - Heads Up To All

[8600RPM]

Sorry but what link is there showing this has happened to stock cars? Lots of speculation but I've not read of one. JB4 pushes the most boost so most chance shit will break. Why are JB4 owners getting so defensive?

[BMWM.D.]

Originally Posted by Cloud9blue

The thing is that Dinan claims that their piggyback modifying timing, but I am 99% sure it is not the full timing control as in a flash based tune that they led you believe. My guess is that it is simply a crankshaft position sensor (CPS) offset to stock/existing timing map just like the JB4, since I don't see any other way of modifying the timing otherwise without full ECU control. Correct me if I am wrong though!

FYI, JB4 controls fueling as well, since there is no way to turn up the boost while not increasing the fueling unless you want to run super lean and have some crispy burnt exhaust valves! Piggybacks are a mean to an end, for best control, it is always best to tune with ECU flash and perhaps stacking flash tune with a piggyback in certain applications that requires direct boost control (upgraded turbos, etc.). But there really isn't anything special about this $2.5k piggyback other than the Dinan badge.

Yeah, I don't know all the details on what Dinan's module can actually do. But as far as controlling fueling goes, I mean actually commanding a different lambda value. You really need a flash tune to do that. The beauty of these turbo BMW motors is that they have factory widebands and closed-loop fuel control. That allows the piggybacks to do what they do without access to the tables in the DME. The JB4 isn't really doing anything with fueling. It's really a boost controller, and the DME does the rest. It just continues to target factory lambda values.

I'm just not a big fan of that approach myself. A buddy of mine got a JB4 for his N55 car (no Cobb support for his 2012 model) and wanted to switch to E85 blends. I contacted Burger to ask how this system worked and could safely run ethanol blends without modification of fuel scaler (i.e. stoich AFR) tables. The answer? At WOT, it manipulates the high-pressure fuel sensor signal to alter fuel mass -- but at idle and cruise, it completely relies on fuel trims. That's just something I'd never do with an ~E40-E50 blend. But to each their own.

[Mike@N54Tuning.com]

Originally Posted by BMWM.D.

Yeah, I don't know all the details on what Dinan's module can actually do. But as far as controlling fueling goes, I mean actually commanding a different lambda value. You really need a flash tune to do that. The beauty of these turbo BMW motors is that they have factory widebands and closed-loop fuel control. That allows the piggybacks to do what they do without access to the tables in the DME. The JB4 isn't really doing anything with fueling. It's really a boost controller, and the DME does the rest. It just continues to target factory lambda values.

I'm just not a big fan of that approach myself. A buddy of mine got a JB4 for his N55 car (no Cobb support for his 2012 model) and wanted to switch to E85 blends. I contacted Burger to ask how this system worked and could safely run ethanol blends without modification of fuel scaler (i.e. stoich AFR) tables. The answer? At WOT, it manipulates the high-pressure fuel sensor signal to alter fuel mass -- but at idle and cruise, it completely relies on fuel trims. That's just something I'd never do with an ~E40-E50 blend. But to each their own.

FYI, that isn't true. You can target different lambda values with the JB4. With the Dinan I'm not sure but I imagine it's using the same technique.

[Myrder]

Lol It's like the old days of N54 all over again, this group never surprises me. It will be hilarious when BMS holds all the records for the S55 a few years from now and people are still calling it "just a piggyback" and "something I wouldn't run". JB4 paired with a backend flash is the only way to go.

[BMWM.D.]

Originally Posted by Mike@N54Tuning.com

FYI, that isn't true. You can target different lambda values with the JB4. With the Dinan I'm not sure but I imagine it's using the same technique.

Did something change? Because that looks like just about every other JB4 dyno I've ever seen. Super lean on the lower end (until well after peak torque usually), then a little too rich for my taste on the top end. That dyno was also using meth, so that's another factor.

I don't really consider manipulating the fuel pressure sensor to be proper tuning, though. I know that's how the N55 JB4 was allowing ethanol blends. Then it just let the fuel trims correct during low-load situations. That's exactly how Terry explained it to me when I asked the pointed question of how you can safely run these ethanol levels without fuel scaler adjustments. Maybe he's figured out some other way to do it on the S55s? I dunno...

[Mike@N54Tuning.com]

Just spoke with ER and we should see a Charge Pipe from them by the end of February if not a little sooner. Its actively in development as we speak.

Our M3 should arrive this week hopefully (fingers crossed) so I will be able to do some testing on the pipe as well and once I get my hands on one I will snap some pics for you guys.

Mike

[GGreek5]

Originally Posted by 8600RPM

Sorry but what link is there showing this has happened to stock cars? Lots of speculation but I've not read of one. JB4 pushes the most boost so most chance shit will break. Why are JB4 owners getting so defensive?

This happend to my car with only 500 miles on it. Bone stock. I thought I posted on the first page of this thread. The pipe split in two. Dealer ended up replacing both pipes after I showed them what was wrong. Supposedly they couldn't find the problem even though I showed them, and sent pictures to them, and gave them the pn lol. Eventually they apologized, repaired it, and spoke to BMWNA about this being a weak point, and a problem on multiple cars. They were trying to get a tsb for it.

So it happens on stock vehicles as well as modded.

[Mike@N54Tuning.com]

Originally Posted by GGreek5

This happend to my car with only 500 miles on it. Bone stock. I thought I posted on the first page of this thread. The pipe split in two. Dealer ended up replacing both pipes after I showed them what was wrong. Supposedly they couldn't find the problem even though I showed them, and sent pictures to them, and gave them the pn lol. Eventually they apologized, repaired it, and spoke to BMWNA about this being a weak point, and a problem on multiple cars. They were trying to get a tsb for it.

So it happens on stock vehicles as well as modded.

This is the same story on the N54 and N55 E9x and N55 F-series cars. Its amazing BMW hasn't learned their lessons that they need to beef up their charge pipe. I deal with cracked or or disintegrated charge pipes a couple times a week. We even specifically stock replacement N54 and N55 pipes so that if a customers pipe crack or breaks we have one ready to go same day. I guess I will need to start stocking the S55 ones as well.

Such a shame on BMW's part, but keeps the aftermarket companies like ER busy

Mike

[Tiago@VRSF]

Originally Posted by GGreek5

This happend to my car with only 500 miles on it. Bone stock. I thought I posted on the first page of this thread. The pipe split in two. Dealer ended up replacing both pipes after I showed them what was wrong. Supposedly they couldn't find the problem even though I showed them, and sent pictures to them, and gave them the pn lol. Eventually they apologized, repaired it, and spoke to BMWNA about this being a weak point, and a problem on multiple cars. They were trying to get a tsb for it.

So it happens on stock vehicles as well as modded.

There is actually a TSB out for thie chargepiles, I was informed by my tech.

[BMWM.D.]

Originally Posted by Mike@N54Tuning.com

This is the same story on the N54 and N55 E9x and N55 F-series cars. Its amazing BMW hasn't learned their lessons that they need to beef up their charge pipe.

Such a shame on BMW's part, but keeps the aftermarket companies like ER busy

Mike

I don't think it's fair to blame BMW for a charge pipe breaking when someone adds 50% or more to the stock boost pressure. Now, on a stock car that's a different story -- not acceptable at all. But in the ~9 years I've been dealing with warranty claims on these turbo BMW engines on a daily basis, I've only seen a couple charge pipe failures on stock cars. And I'm talking about my entire shop, not just me personally. It's not as common as some people might think. Compared to a lot of other N54/N55 failures, it's low on my list of things to be worried about.

[Mike@N54Tuning.com]

Originally Posted by BMWM.D.

Did something change? Because that looks like just about every other JB4 dyno I've ever seen. Super lean on the lower end (until well after peak torque usually), then a little too rich for my taste on the top end. That dyno was also using meth, so that's another factor.

I don't really consider manipulating the fuel pressure sensor to be proper tuning, though. I know that's how the N55 JB4 was allowing ethanol blends. Then it just let the fuel trims correct during low-load situations. That's exactly how Terry explained it to me when I asked the pointed question of how you can safely run these ethanol levels without fuel scaler adjustments. Maybe he's figured out some other way to do it on the S55s? I dunno...

The dyno chart is testing 29psi at various air/fuel ratios, from 13:1 to 11.5:1. You can see the variances in each run in the dyno trace. Their observations on the dyno and track were the car seems to be happier at surprisingly leaner air/fuel ratios than they expected.

The fine details of how its all setup and operates isn't my department so you'd need to direct any questions on that to BMS. Although I'm sure they consider a lot of it proprietary given how many piggyback competitors there are these days.

Mike

[Mike@N54Tuning.com]

Originally Posted by BMWM.D.

I don't think it's fair to blame BMW for a charge pipe breaking when someone adds 50% or more to the stock boost pressure. Now, on a stock car that's a different story -- not acceptable at all. But in the ~9 years I've been dealing with warranty claims on these turbo BMW engines on a daily basis, I've only seen a couple charge pipe failures on stock cars. And I'm talking about my entire shop, not just me personally. It's not as common as some people might think. Compared to a lot of other N54/N55 failures, it's low on my list.

Over the last year I've probably dealt with about 30-40 N54/N55 stock charge pipe failures on cars with no tune at all. Thats a pretty high number. I know of a lot that have had their charge pipes replaced under warranty by BMW as well (also stock tune) I am only one vendor so imagine the numbers are much higher.

Mike

[BMWM.D.]

Originally Posted by Mike@N54Tuning.com

The dyno chart is testing 29psi at various air/fuel ratios, from 13:1 to 11.5:1. You can see the variances in each run in the dyno trace. Their observations on the dyno and track were the car seems to be happier at surprisingly leaner air/fuel ratios than they expected.

The fine details of how its all setup and operates isn't my department so you'd need to direct any questions on that to BMS. Although I'm sure they consider a lot of it proprietary given how many piggyback competitors there are these days.

Mike

I've talked with Terry about it. Once you have a strong understanding of tuning, the different sensors these piggys tap into, and how these engine management systems really tick, things make more sense.

It looks like the S55 setup is similar to the N55 setup, meaning the only way it can alter WOT fueling is by manipulating the rail pressure sensor signal. But it doesn't do this at idle and cruise, so you're stuck with fuel trims trying to correct for ~E30 fuel. And the fuel-mass wires are optional -- even on the S55 JB4, and even then it really isn't like dialing in a target lambda value like with a flash tune.

I don't like getting into technical discussions/debates with someone who has something to gain or lose by promoting a product, though. I have no dog in this fight, just lots of experience with these cars as a hobby and career, as well as tuning different vehicle platforms.

Originally Posted by Mike@N54Tuning.com

Over the last year I've probably dealt with about 30-40 N54/N55 stock charge pipe failures on cars with no tune at all. Thats a pretty high number. I know of a lot that have had their charge pipes replaced under warranty by BMW as well (also stock tune) I am only one vendor so imagine the numbers are much higher.

Mike

As the cars get older, plastic parts are going to become more likely to crack. But with the number of N54/N55 cars we service and repair, you start to see failure patterns over time. I've been doing this since well before the N54 hit the streets here in the US, and had an early E90 myself back in the early stages of the high-pressure fuel pump fiasco. But in all those years, I've only seen 2 (I think) broken charge pipes come through.

On the other hand, the number of injectors, fuel pumps, ignition coils, electric water pumps, EPDWs, etc. that I've seen (or personally replaced) is something I'd never be able to keep track of. Just going off the law of averages here. Maybe higher mileage cars or cars in more extreme climates have more trouble with this, but it's not what I've seen here in CA.

I'm still running my stock charge pipe at 18 psi or so, with no worries to be honest.

[MasterC17]

Originally Posted by Mike@N54Tuning.com

The dyno chart is testing 29psi at various air/fuel ratios, from 13:1 to 11.5:1. You can see the variances in each run in the dyno trace. Their observations on the dyno and track were the car seems to be happier at surprisingly leaner air/fuel ratios than they expected.

The fine details of how its all setup and operates isn't my department so you'd need to direct any questions on that to BMS. Although I'm sure they consider a lot of it proprietary given how many piggyback competitors there are these days.

Mike

That's exactly what I have noticed, this engine likes to stay more lean than rich. If it dips below 12:1 that is when I normally see problems.

[MaynardZed]

A JB4 tuned car blows a chargepipe and this becomes "pick on the Dinan tune" thread?

[BMWM.D.]

Originally Posted by MaynardZed

A JB4 tuned car blows a chargepipe and this becomes "pick on the Dinan tune" thread?

It really had to do more with a Dinan tune owner claiming the JB4 caused the failure and that Dinan's tune would prevent it. Although more boost = more risk, we all know that isn't the case.