"Sharp edges" possible issue on intake after 62mm throttle body upgrade causing whistle?

[Jezza]

Run a type A analysis on each run parameter... 10 runs each parameter, keeping all the contributing factors within a margin for each parameter, and Ithink your repeatability will fail what you are attempting to preach.

I could run 50 and there would still be excuses. I'm not preaching anything, just reporting my results. I don't sell these things or even use them. To say there is no increase in power is just 100% wrong and the facts don't back it up. Maybe someone else can do 500 pulls and show there is no increase as that is now the opinion with no data.

 

[jeepguy03]

I ran a BBK 62mm TB on one of my XJs back in the day. I had the same whistle noise, tried several different gaskets thinking that was the problem. Nope, it was the throttle body. I ended up running a 60mm bored one (just removes the slight taper from the stock TB) from a local machinist/Cherokee enthusiast, and I had no whistle. Definitely a BBK problem.

With that said, all a bored TB is doing is acting like you are pressing the gas pedal harder which seems like better acceleration, and as others have mentioned at WOT the stock one flows plenty of air. All it really does it make the acceleration more jumpy from a stop, which IMO would be annoying on a manual trans.

 

[SSTJ]

I ran a BBK 62mm TB on one of my XJs back in the day. I had the same whistle noise, tried several different gaskets thinking that was the problem. Nope, it was the throttle body. I ended up running a 60mm bored one (just removes the slight taper from the stock TB) from a local machinist/Cherokee enthusiast, and I had no whistle. Definitely a BBK problem.

With that said, all a bored TB is doing is acting like you are pressing the gas pedal harder which seems like better acceleration, and as others have mentioned at WOT the stock one flows plenty of air. All it really does it make the acceleration more jumpy from a stop, which IMO would be annoying on a manual trans.

@aidanm, I know we hijacked your thread a bit, but this one is back on topic and replies to your original question.

 

[Jerry Bransford]

With that said, all a bored TB is doing is acting like you are pressing the gas pedal harder which seems like better acceleration, and as others have mentioned at WOT the stock one flows plenty of air. All it really does it make the acceleration more jumpy from a stop, which IMO would be annoying on a manual trans.

Exactly, too bad the nuances of that will be lost on several in this thread.

 

[Brianj5600]

@Jezza have you ever measured A/F on the stock motor in open loop? I'm curious if the open loop fuel tables are as bad as the spark tables.

 

[Mikee024]

My original throttle body whistles. Both ends of the butterfly valve leaked per my boost leak check using compressed air and soapy water.

I purchased a 62mm BBK and the whistle went away, but the leaks at the end of the butterfly shaft were even worse so I returned the BBK.

I'll need to get my original TB rebuilt when I get back to my rig this summer. Not sure who I'll contact for the TB rebuild. I mention this in case it's your issue.

Edit: BBK TBs are known to have vacuum/boost leaks. I only tried the BBK since Oreillys had one in stock and the salesman encouraged me to try it and said I could return it if it leaked (which I warned him was likely to happen).

 

[Jezza]

@Jezza have you ever measured A/F on the stock motor in open loop? I'm curious if the open loop fuel tables are as bad as the spark tables.

When I did the testing on the intake tube I was logging wideband AFR. All the runs were leaner than I would like. That is why I think coupled with a tune there would be even more to be had.

 

[MikekiM]

No I don’t have a cold air intake but am getting one soon, just got the banks exhaust and installing it this weekend

I don't know what you're going for with your build and, I am not trying to be disrespectful or a douche... You have do what you want, spend your money how you want to and then, enjoy your jeep. However, the three mods you did don't do as as much performance as the manufacturers and distributors want you to believe. I won't say zero performance but it's questionable if the the ROI is there at all. Lots of things you could do with that money that would be far better for our aging vehicle. Sounds cool if that's your thing but limited ROI for sure.

As far as the CAI goes.. I put one in my last JK. The sound was cool. It was an easy bolt on. I did it the year before SuperStorm Sandy hit. I tried three times to get back to my house during the floods and three times I turned around for fear that with the water level as high as it was I would hydro my JK given how much lower the CAI sat. I know it's a long stretch, but... I'll never do a CAI again in part because of this.

 

[aidanm]

@aidanm, I know we hijacked your thread a bit, but this one is back on topic and replies to your original question.

Lol thank you I was wondering when someone was gonna realize that 😂

 

[C.J. Roberts]

Lol thank you I was wondering when someone was gonna realize that 😂

Happens all the time. You might as well get used to it.

 

[aidanm]

Happens all the time. You might as well get used to it.

I have 👍 Also I still have my old throttle body, should I just machine that and would it feel the same?

 

[1904-06LJR]

This should fix your whistle. Notice the "swirled" machining on the inside, which effectively twists and spins the air and this diminishes the whistle sounds. It's likely this too, will gain additional throttle response...

All kidding aside, x2 with what @MikekiM said...spend the money how you like whether we on the forum agree with your or not. It's your Jeep!

 

[tr21triton]

Man with all that whistling going on put a TURBO sticker below the 4.0 one and list it for $30k on bookface ! saw a 1997 Rubicon on there the other day !!!!
https://www.facebook.com/marketplac...wse_serp:00f0bf21-0016-4be8-9802-ed95dbbd21a4

 

[Mikee024]

Man with all that whistling going on put a TURBO sticker below the 4.0 one and list it for $30k on bookface ! saw a 1997 Rubicon on there the other day !!!!
https://www.facebook.com/marketplace/item/1194031834583344/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp:00f0bf21-0016-4be8-9802-ed95dbbd21a4

I have two whistles maybe I should list it as “rare!” for no less than $

 

[tr21triton]

I have two whistles maybe I should list it as “rare!” for no less than $

man so your the one who got the only prototype dual turbo 4.0, you lucky joker, PRICELESS !

 

[aidanm]

man so your the one who got the only prototype dual turbo 4.0, you lucky joker, PRICELESS !

Nah I have two as well

 

[Zorba]

Put a velocity stack on the intake - that'll fix it for sure!

 

[Mikee024]

Nah I have two as well

Imagine if we teamed up!

 

[Oldguy]

how can more air with the same amount of fuel make a difference?

 

[SkylinesSuck]

How do you mean?