Cobb and JB4 Dyno Results

[Terry@BMS]

Hey guys,

Spent a couple hrs on the dyno today collecting data. I have logs of every run and it will take some time to sort through everything. But I'll just post the dyno charts and a few quick notes for now and add some additional logs and analysis later.

The test car is our 2008 135i, 30k miles, 100% stock other than a dual cone intake and BMS oil catch can. Fuel is 91 octane with a can of NOS octane boost added to the full tank. Basically, 93 octane.

I have around 65 emails staring me down right now so some quick comments.

1) The JB4's low end approach of running less boost, less fuel, but more advance resulted in similar torque figures.
2) The JB4 map 1 is a little less aggressive up top than the Cobb "Aggressive" map and JB4 map 2 a little more aggressive up top.
3) I don't think a piggyback will be able to touch their air/fuel ratios below 5000rpm, but with less boost and more advance I don't think they need to either.
4) Just my personal opinion but I find the Cobb "linear" maps horrible to drive and the "normal" maps extremely too boost happy. Half throttle 12psi happy. I prefer the mapping we've setup in the JB4 which is around 8psi at half throttle. But, these things can always be adjusted.
5) Overall, I don't foresee JB4 owners trading in for the Cobb for improved drivability or power but the install process itself is easier which is very important to quite a few. I suspect Cobb will take over Vishnu's business on the top end of the market and then the question for many customers will be become whether the extra install time is worth the lower cost and additional features the JB4 offers.

[leo985i]

Very nice data, maybe next time you should try dynoing with FBO (no meth) for us that have FBOs. Thanks for posting. Not jumping to Cobb anytime soon.

[Laloosh]

People need to realize one gear dyno pulls is not where to cobb excels. The results are nice and the logs show the cobb car is def more happy however its real world results that matter. Post shift, multi gear dynos showing power with logs showing boost/timing/af are real world results and that where the cobb tune excells over any piggy out there.

[Payam@BMS]

good gains on both tunes. The Jb4 shows stronger numbers, from what I've heard a nice DD tune as well. Cobb is new so I don't have too much info on that, but seems they're doing well.

[carcars]

I like the COOB afr

terry maybe it could improve a bit for the boys JB4

[enrita]

I like the COOB afr

terry maybe it could improve a bit for the boys JB4

yeah lets see if he can match it and disprove that only a flash can achieve that.

[Terry@BMS]

Here is a set of logs that I think do a good job of demonstrating the basic tuning differences. They are JB4 map 1 (no cps), Cobb Aggressive, and just for comparison Cobb Drive. The dyno charts of these runs are in the first post.

You'll notice at 3000rpm the JB4 map 1 runs ~10.5psi @ ~10 degrees and produces around 370wtq. While the Cobb Aggressive runs ~13psi @ ~3 degrees and produces a similar 375wtq.

[Terry@BMS]

I like the COOB afr

terry maybe it could improve a bit for the boys JB4

Per comment #3 up there I don't think a piggyback can run that rich down low, but I also don't think a piggyback needs to run that rich down low. We can certainly run richer than it is set now on map 1 & 2 but for the above tests I wanted everything to be off the shelf for a fair comparison. The JB4 fuel curve is essentially unchanged from the JB3 days. Over 7500 cars have run this curve over the last four years with no negative EGT related effects observed. Not to mention however many procedes have used the fuel curve. With less boost and more advance down low you simply don't need that much fuel. Especially when the DME is injecting fuel multiple times per stroke.

[carcars]

Per comment #3 up there I don't think a piggyback can run that rich down low, but I also don't think a piggyback needs to run that rich down low. We can certainly run richer than it is set now on map 1 & 2 but for the above tests I wanted everything to be off the shelf for a fair comparison. The JB4 fuel curve is essentially unchanged from the JB3 days. Over 7500 cars have run this curve over the last four years with no negative EGT related effects observed. Not to mention however many procedes have used the fuel curve. With less boost and more advance down low you simply don't need that much fuel. Especially when the DME is injecting fuel multiple times per stroke.

I have seen some here in Spain afr of boys playingin mapa6 tuner chips and scary to see the afrcurve well below 11.5


I trust your JB3 / 4 that I carry in my car since 2008, but I think we should improve a little afr in low rpmred line

[Sticky]

How does Cobb pricing compare to Vishnu?

[themyst]

How does Cobb pricing compare to Vishnu?

Msrp on the Cobb ap is 895, procede is 945, but both can be had cheaper if you shop around or negotiate.

[xbox_fan]

Cobb is somewhat cheaper, HPF list both tunes for $895 (COBB) and $945 (PROcede)

[Payam@BMS]

crazy ppl that don't go with JB4 for half the price and more power/reliability.

[Terry@BMS]

I have seen some here in Spain afr of boys playingin mapa6 tuner chips and scary to see the afrcurve well below 11.5


I trust your JB3 / 4 that I carry in my car since 2008, but I think we should improve a little afr in low rpmred line

We're working on the low RPM fueling issue. Not because we need more fuel wit the current maps, but because in order to to make more torque with pump gas than we do now we will simple need more fuel.

[Sticky]

crazy ppl that don't go with JB4 for half the price and more power/reliability.

A lot of people do.

[Sticky]

Msrp on the Cobb ap is 895, procede is 945, but both can be had cheaper if you shop around or negotiate.

I would simply rather go Cobb at those price levels. Insane the procede is that price still.

[themyst]

I would simply rather go Cobb at those price levels. Insane the procede is that price still.

actually the Procede had a $645 dollar option, apparently he didn't want to compete with BMS on the low end market cause he will get killed. Either way, $945 dollars for a VIN locking tune that loses $150 dollars the second you install it. I'd rather go with a JB4+CPS combo.

[carcars]

We're working on the low RPM fueling issue. Not because we need more fuel wit the current maps, but because in order to to make more torque with pump gas than we do now we will simple need more fuel.

from to mount the new pump and injectors 1m


I have seen a great improvement in the flowrejistros