The T in my head, thoughts?

[Spanky]

Posted by Mykk on fb: "Started making my own set of Zoomies. 304 stainles 2.25" 84 degree mandrel J-bends.
Super stoked to finish welding them together and terrorize the streets."

 

[old round fart]

How does the EFI work with zoomies?

 

[Spanky]

Mykk posted a really neat video of his test drive with the zoomies on fb; I hope he'll post it here . . .

 

[Mykk]

The video Spanky was referring too:

How does the EFI work with zoomies?

The wideband O2 sensor is not working well in the current config. I need to come up with a plan B. I'm considering running the engine, seeing which tube gets hottest with a thermo gun and mounting the O2 bung in that cylinders tube so as the EFI is reading the leanest cylinder at all time. It's not ideal, but better then nothing.

 

[old round fart]

Can you use thermocouple sensors instead of O2 sensors? I think there would be programing involved but it seems you get same outcome.

 

[Spanky]

Check this out . . . turn up your volume!

BMW M60B44 Rat Rod Project - YouTube

 

[DonnyRay]

I'm happy for you Mykk. Sounds strong.

 

[Spanky]

Mykk, you've definitely got the right sound with those zoomies. Much better than the old system!

 

[old round fart]

Mykk, do you have any baffles in your zoomies?

 

[Gerry]

I only have one sensor. Its in the no 8 tube as recommended by Kinsler. I also made a cover for the sensor to 'tidy' it up. Got to put a small slot in the top and bottom to allow air movement as its need to know the ambient air condition as well as the exhaust gas.

 

[old round fart]

Gerry, where did you put the sensor? Cole’s to the head or the exit? I want to run Holley Sniper and wonder if that sensor would work for me. Guess I need to ask Holley. Lol

 

[Gerry]

Apologies. I had brain fade and said #8 pipe. I meant #2. Dohhhh

After reading it up and deciding that it was OK to put it at, or less than 1 metre from the port. The info also said to make sure there is enough pipe on the downstream side to eliminate back flow of air and gasses to stop false reading sfrom exhaust gas being diluted with clean air.
I put it as close to the body as I could to try and hide it a little and reduce to length of the wire to its minimum.

 

[Mykk]

I'm happy for you Mykk. Sounds strong.

Thank you, it's not fully tuned yet so there is still some more oomph to be had. I should probably lay off the throttle until I can finish tuning, but I can't help myself.

Mykk, you've definitely got the right sound with those zoomies. Much better than the old system!

Thank you, I agree. The look is way better, it is way louder for sure.

Mykk, do you have any baffles in your zoomies?

Yes, I've been experimenting with washer "lollipop" baffles at different pipe depths to see if I can shape the tone just a bit. It doesn't really lower the dB much but it seems to shape the resonant frequency of the pipes. With the baffles deeper in the pipes you get more boom, can hear the pipe diameter and even sounds a bit flappy.

With the baffles moved out towards the end of the pipes the resonance frequency shifts to a higher pitch, some of boom disappears. But so does some of the flap sound. It has more a nitro sound (to my ears) and is a bit more controlled sounding.

From my experiments the sweet spot on this set up is around 3" pipe depth from the outlets. It still has some boom, slightly flappy at idle but almost sounds slightly chambered at cruise.

In the video clip that Spanky shared above, the idle and rev at the beginning of the clip is a 3" baffle depth. The driving around down clips are with a 2" baffle depth. Not physically much difference but a big noticeable difference in sound.

For the long term I have set of motorcycle lollipops known commercially as the DK Thunder Torque Inserts to replace my temporary washers welded to coat hanger wire. Again, it doesn't do much for dB but definitely shapes the frequencies. However the "Back pressure" or "Anti-reversion" or whatever is going on with the restriction is absolutely helping the low rpm response, cruise rpm torque and throttle response.

 

[Mykk]

I only have one sensor. Its in the no 8 tube as recommended by Kinsler.

I'm really glad to hear that as that was my plan for the O2 too

 

[Gerry]

See my above post, (couple up) because I used #2....not #8 plus some info on placement that may help.
but I think Kinsler said #8 would be the choice for only one sensor. Of course they initially said to use 8, one in each tube, bu understood my DEEP concerns with looks for the Fad.

 

[old round fart]

Mykk any info as to how you are moving the baffles and such would be greatly appreciated. I’m really interested in your process.

 

[Mykk]

Mykk any info as to how you are moving the baffles and such would be greatly appreciated. I’m really interested in your process.

Now keep in mind these are temporary just find the depth that seems to be the best compromise of sounds. Once I'm set on a baffle depth I'll drill the holes in the pipes for the DK TTI's

 

[old round fart]

Thanks! That is totally slick! I love that idea. Thanks Mykonos!

 

[Mykk]

A big day for me and my project today, this morning was the inspection at the Arizona MVD (DMV) to get assigned a VIN #, and thus it's registration. Previously I was out on the road with 3 day passes using the frames serial #. Because I had Manufacturer Specified Origin (MSO) certificates from Speedway motors for both the frame and the body the MVD treated them as a 'bill of sale' so the inspection was knocked down from a Level III to a level II. Not only was the inspection easier they actually titled the car as a 1923 model year because the MSO from speedway stated a "23 T" for a brand new aftermarket frame and fiberglass body. Now I get to use a cool looking Copper Vintage license plate in Arizona. And I guess my car is now legally a 1923 Special Construction. Once Hagerty approves the insurance, I'll be good to go.

 

[Spanky]

In Missouri, the Highway Patrol not only inspects the car, but they attach the assigned VIN with special rivets, featuring a small outline of the state's shape (hard to see in the picture.)