[3002 tii]

Originally Posted by gordon@

Yes, and it virtually made no difference. I'm sure today with BPC tuning there would be some gains.

http://www.e90post.com/forums/showthread.php?t=36024

I posted a dyno with and without just few posts above

[GORDON.M3]

Originally Posted by 3002 tii

I posted a dyno with and without just few posts above

Looks good, but would like to see what happens after the ECU starts to learn and recalibrate itself.

[hassmaschine]

People think these DMEs are slow/stupid, and that they take hundreds of miles to adapt - couldn't be further from the truth. It really only takes about 3-4 WOT pulls - it's not voodoo magic. And even the difference after the first couple pulls isn't very much.

[Biginboca]

I just ordered the WCR BBTB today. Bob updated my tune to a 7500 rpm redline a few days ago and I want to get more air in to make power at those higher rpms. Engine feel like power falls off a bit around 7100 and the dynos I’ve seen on other engines support what I’m feeling. I’m also doing a ram air mod like the Dinan intake with the BBTB.

I figured since I’ve already got the MILVs, headers, and intake mods that the BBTB might be helpful. I’m looking to support making power up to the new redline and the dyno in this thread shows that’s the effect of the BBTB so I took the plunge.

[CobraMarty]

That's great. I can't wait to see the result.

WOW 7500rpm pulls!

I just bought a used stock TB to return for the core fee.
I agree and predict just what you are hoping for. I am sure that there is a slight restriction in the TB at higher rpm with the stock TB.

Remember that the throttle plate is usually in the full open position especially during a WOT run. A slight restriction in the bore of the TB will decrease power.

Open it up and let it flow!!
Maybe 3-5 HP at the top end? IDK, maybe more!

[hassmaschine]

I actually think it's the 3 stage manifold that causes the high RPM power drop - not the throttle or something else. I dont think it's possible to make power over 6900 without a different manifold entirely - it's not airflow thats the problem, its the resonance of the 3rd stage. It's only tuned for a narrow band between 4500-6900, beyond that it actually has the opposite effect.

[Biginboca]

Originally Posted by hassmaschine

I actually think it's the 3 stage manifold that causes the high RPM power drop - not the throttle or something else. I dont think it's possible to make power over 6900 without a different manifold entirely - it's not airflow thats the problem, its the resonance of the 3rd stage. It's only tuned for a narrow band between 4500-6900, beyond that it actually has the opposite effect.

I also think you are right, it would likely make the most absolute power at the upper rpms with a different manifold. Like a N54 manifold maybe.

But I am hoping there’s an improvement with the BBTB from where it is now and 3IM. I don’t want to give up the midrange I’ve got now with the 3IM to favor upper RPMs only since my car is a daily. Looking at that Big Bore Throttle Body dyno posted earlier in this thread there’s a nice bump from 6500 and up:



Like Marty is saying, I would love to pick up 5HP on those last 1000 rpms from 6500-7500. And there’s MILV’s and headers on here also which that dyno doesn’t show hopefully the mods all compliment the BBTB.

Here’s another dyno showing MILV’s with a 3IM posted by BPC in the MILV’s thread. This dyno doesn’t have the BBTB or the 7500 rpm redline, and it looks like they stopped the pull well under 7k RPM’s. The top end power bump from the MILV’s looks good too on this dyno. I think (hope) the mods will synergize somehwhat even though I want to keep the 3IM.

[AWSB328iM]

This engine needs ITBs!

[Phyrexia]

This engine will literally run without an intake manifold, I'm not sure if ITBs is an excellent use of R&D resources.

[hassmaschine]

yeah, I mean, i want to do it - but more for the cool factor and to be able to run a different airbox/plenum. Adding throttles makes no sense really, because it doesn't use the throttle anyway. You're not going to gain any power from ITBs.

[Biginboca]

I did a bunch of research on BBTB's online last night. Wasn't able to find anything really for the N52 except more of what’s already been discussed in this thread, but lots of threads for various platforms (mustangs/Chevy/Honda)

The consensus I found is they reduce intake velocity which on a stock engine will make a torque loss under 4-5k rpms and probably add the same amount of torque and power back to the upper rpms. So for driveability maybe a net zero, maybe a small gain, maybe even a loss. But overall not really a huge difference.

The consensus also was on a built motor with cams/headers/intake mods they will add noticeable power up top cause those motors can now make use of the added flow.

Hoping that second scenario applies to my motor. It seems like it would, the MILV's are effectively doing the same as cams at full throttle because I'm getting more valve opening than stock. Plus intake mods and headers seems like it should be the right scenario to allow the BBTB to have an effect.

Which leads me to a question... Bob BPC told me that as long as the MAF housing stays the same diameter the engine will adapt to increased airflow. No tuning necessary for ram air or BBTB mod. And reading what Hassmachine wrote above leads me to believe with MAF correctly measuring more air coming in wouldn’t the DME add more fuel, so engine would have more power at the upper RPMs?

[hassmaschine]

Originally Posted by Biginboca

I did a bunch of research on BBTB's online last night. Wasn't able to find anything really for the N52 except more of what’s already been discussed in this thread, but lots of threads for various platforms (mustangs/Chevy/Honda)

The consensus I found is they reduce intake velocity which on a stock engine will make a torque loss under 4-5k rpms and probably add the same amount of torque and power back to the upper rpms. So for driveability maybe a net zero, maybe a small gain, maybe even a loss. But overall not really a huge difference.

The consensus also was on a built motor with cams/headers/intake mods they will add noticeable power up top cause those motors can now make use of the added flow.

Hoping that second scenario applies to my motor. It seems like it would, the MILV's are effectively doing the same as cams at full throttle because I'm getting more valve opening than stock. Plus intake mods and headers seems like it should be the right scenario to allow the BBTB to have an effect.

Which leads me to a question... Bob BPC told me that as long as the MAF housing stays the same diameter the engine will adapt to increased airflow. No tuning necessary for ram air or BBTB mod. And reading what Hassmachine wrote above leads me to believe with MAF correctly measuring more air coming in wouldn’t the DME add more fuel, so engine would have more power at the upper RPMs?

Basically, yes.


http://www.e90post.com/forums/showpost.php?p=22825886&postcount=34

[PORTMOODY]

in for the results.

[Xencer]

Hm, I have a spare throttle body laying around that came with my 3IM, I might jump on this because why not, lol. I need headers though. But I would also rather swap a 6MT into my car above all else.

[Xencer]

Originally Posted by hassmaschine

People think these DMEs are slow/stupid, and that they take hundreds of miles to adapt - couldn't be further from the truth. It really only takes about 3-4 WOT pulls - it's not voodoo magic. And even the difference after the first couple pulls isn't very much.

As an automotive technician I can tell you that short fuel trims are usually adjusted in a second and long term FT is learned over a slightly longer time, I've seen it adjust as quick as a minute. So with this being said I don't think a tune is needed for the BBTB, because that is what the DME will adjust, fuel trims.

[hassmaschine]

Yeah, STFT on the N52 is much faster than 1 second.

[Xencer]

Well, when you're data logging the refresh rate is around 1000ms so yeah you right lol

[rjahl]

Originally Posted by Xencer

Well, when you're data logging the refresh rate is around 1000ms so yeah you right lol

Your data log refresh should be around 100 milliseconds

[Biginboca]

BBTB arrived and was installed today. Haven’t had a chance to do any true testing yet but it’s not throwing codes and car is running strong to 7500. But dyno says the power is not starting to fall off at 6800 like with the stock TB, but I need to do some testing to see for sure if there’s an improvement.

Here’s a few pics with the stock TB (black butterfly). You can see how the butterfly in the new throttle body has much less side profile, like blocks a lot less air when it’s open which it is always normally. The B.B. doesn't have those trusses on the butterfly like the stock one, and it also is only a half circle for the shaft while the stock is a full circular center shaft. So there's less obstruction on the butterfly plus it’s about 4mm larger diameter. (Probably more like 3.5mm cause I measured my BBTB at 79.5mm ID and stock is supposed to be 76mm ID.

No question it will flow better just need to test and see if it actually makes a difference in the cars performance.

[Biginboca]

Hopefully we will see some dynos posted on this TB vs the OEM. In the meantime I have been doing my own testing and wanted to share what I’m finding...

With my set up and the BBTB there’s no question I’m experiencing a decent power drop from 4000-5000 rpms. It’s taking a lot more time, like a 1/4 second difference to pass through those revs:

WOT time to increase from 4000rpm to 5000rpm in 3rd Gear

1.95” OEM Throttle Body

2.20” WCR Throttle Body

Above 5000 I’m seeing all improvements. I don’t have dyno data but I have time data. This is what I measured, all tests done 83 degrees with tank filled immediately before all tests and exact same road and conditions. These are all WOT in 3rd gear pulls:


60-80mph Acceleration Time:

3.40” OEM Throttle Body

3.30” WCR Throttle Body


60-90mph Acceleration Time:

5.38” OEM Throttle Body

5.20” WCR Throttle Body



WOT time to increase from 4500rpm to 6000rpm in 3rd Gear

3.02” OEM Throttle Body

2.95” WCR Throttle Body


WOT time to increase from 6000 to 7300rpm in 3rd Gear

3.09” OEM Throttle Body

3.00” WCR Throttle Body


WOT time to increase from 5,000rpms to 7300rpms in 3rd Gear

5.09” OEM Throttle Body

4.90” WCR Throttle Body


WOT time to increase from 4500rpm to 7300rpm in 3rd Gear*

6.11” OEM Throttle Body

5.95” WCR Throttle Body

* the spread here is narrower than the 5000-7300rpm pulls because the OEM Throttle Body is outperforming the WCR one from 4000-5000

I will have to do some 0-80 timed runs with the BBTB and see how they compare with the runs I logged with my OEM, but I’m very confident there’s a trade off of midrange on my car with the BBTB. But in the end I’m getting from 60-90mph about .2 seconds faster with the WCR throttle body so it’s probably a worthwhile trade off.

[hassmaschine]

It might be a velocity thing. There's potential that we could reduce the throttle opening at those RPMs you're seeing a reduction in acceleration to bring the intake velocity back up to stock, and then open it back up at higher RPM where the extra flow is beneficial.

People don't realize this but that's how many E-throttle systems work, and is one of the key advantages. You actually don't always want the throttle to be completely open because the intake velocity drops off.

Well, the good ones anyway.. The bad ones just give you a huge throttle opening at a small pedal input, so you think the car is faster than it really is but then you're already basically at WOT so the rest of the pedal gives you nothing - which is pretty much every car these days.

[CobraMarty]

Originally Posted by hassmaschine

It might be a velocity thing. There's potential that we could reduce the throttle opening at those RPMs you're seeing a reduction in acceleration to bring the intake velocity back up to stock, and then open it back up at higher RPM where the extra flow is beneficial.

People don't realize this but that's how many E-throttle systems work, and is one of the key advantages. You actually don't always want the throttle to be completely open because the intake velocity drops off.

Well, the good ones anyway.. The bad ones just give you a huge throttle opening at a small pedal input, so you think the car is faster than it really is but then you're already basically at WOT so the rest of the pedal gives you nothing - which is pretty much every car these days.

That's cool.
Is there a table for rpm vs throttle position?

Adjusting this would be like a 4th stage in a 3IM.

Something like this-
2000-3000 rpm 60% throttle position
3000-4000 rpm 70%
4000-5000 rpm 85%
5000-7500 rpm 100%