We also have a longer version of the ST (AB 21 STL) to work on the rear exhayst engines, MAC/CMB.Now that sounds good. I also have a ST pipe on my Orlic Nova powered .15 SG. I set the pipe @ 71/4" to start. Will post some results as soon as i can. Richard DReceived my AB 21 ST pipes and had a chance for a short test session today...
HOLY ****!!! B)
Lots of torque & lots of revs!!!
That is how I like a pipe
Fathers day Sale, restarted thru 4th of July
- Thread starter AndyBrown
- Start date
Help Support Intlwaters:
This Fathers day Sale is now the 4th of July sale!
Through July 4th the AB 21 SS, ST, and RX will be on sale for $29.
SS and ST are muffled. The RX is muffled or non muffled.
These are the short pipes suitable for 180 degree headers.
.18 RTR boaters! Take advantage of this sale and get an AB 21 ST pipe for your .18 engine.
Order by E-mail at [email protected] or by phone 386-208-1036.
Paypay is [email protected]
Add $5 for postage
Through July 4th the AB 21 SS, ST, and RX will be on sale for $29.
SS and ST are muffled. The RX is muffled or non muffled.
These are the short pipes suitable for 180 degree headers.
.18 RTR boaters! Take advantage of this sale and get an AB 21 ST pipe for your .18 engine.
Order by E-mail at [email protected] or by phone 386-208-1036.
Paypay is [email protected]
Add $5 for postage
Sean Bowf
Well-Known Member
- Joined
- Sep 6, 2007
- Messages
- 716
Andy, how about the STL for the side exhuast engines...that one on sale too?? If so, how long is it from inlet to the widest part of the pipe?
Sean
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Sean,
I don't have the #'s in front of me, but I think the STL is about 6.5". The ST is about 3.5". It wouldn't take a very long header to run the ST @ 6.5" from plug to joint.
Sean Bowf
Well-Known Member
- Joined
- Sep 6, 2007
- Messages
- 716
No, it wouldnt take much Andy. Looks like the stock MV (miss vegas) header would have it at about 7 inches (plug to joint) on the SS...and I know you said the ST was a little shorter...
Sean
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The front cone on the SS and ST are the same length. The rear cone of the ST is shorter, but the steeper angles in the ST give it more torque, therefore it can run at a shorter length than the SS.
The SS can sqeeze out some high RPM from large ported engines like a Novarossi 21.
The ST is working well on the small port .18's because it will pull more fuel through the ports. This is what is adding the extra torque. If you run it short enough to get the RPM up that will result in more total HP.
Two blades
Active Member
- Joined
- Aug 28, 2007
- Messages
- 32
Hi Andy,
How much to ship one 21SS and one 21ST to Europe?
Do you have both with extra muffling?
Thanks in advance,
Two Blades
How much to ship one 21SS and one 21ST to Europe?
Do you have both with extra muffling?
Thanks in advance,
Two Blades
Sean Bowf
Well-Known Member
- Joined
- Sep 6, 2007
- Messages
- 716
Just a little feedback Andy. I have not got around to trying the ST on my RTR yet...but I did put one on a .21 mono with a CMB LS in it.
The ID of the pipe does not fit over the 180 degree CMB header tube out of the package. Took an hour or so with some sandpaper on the header, and a dremel with a mini sanding drum on the inside of the header end of the pipe to get them to fit over/inside each other.
Sean
The ID of the pipe does not fit over the 180 degree CMB header tube out of the package. Took an hour or so with some sandpaper on the header, and a dremel with a mini sanding drum on the inside of the header end of the pipe to get them to fit over/inside each other.
Sean
- Joined
- Jan 30, 2005
- Messages
- 1,042
Andy, how does the RX pipe compare to the pipe you and John ran years back, when you ran Novarossi? I also had to reduce the dia of a Nova header to fit inside of st and ss pipes. Richard D
Richard or someone,
Could you measure the OD of a new NR header so I can be sure the next batch fit correctly.
Thanks,
Andy
.
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- Nov 2, 2002
- Messages
- 2,662
Thanks Ian!
Sean Bowf
Well-Known Member
- Joined
- Sep 6, 2007
- Messages
- 716
Finally got out to run some of the pipes on one of our RTRs. I first ran my normal pipe which was an unmuffled MACS 3.5 pipe. We will just say it was set at X inches from the plug to the beginning of the convergent cone on the pipe. I lost my best prop a couple days ago...so I used another Y535 I had in my box. Boat was an Aquacraft Miss Vegas with an OS CVRM .18 in it.
39 MPH was my best run with my original pipe. This is about 2 to 3 MPH slower than I expected...guess that prop was better than I remember...
I then tried 21ST pipe. Due to its short length it was set at about X minus 1 inch from the plug to the convergent cone. Really could not get the boat on pipe. Best run with this pipe was 29.X MPH.
We then tried the 21SS pipe. We started at a little shorter than X inches...it ran low 30s. Because this was longer than the ST and faster than we got with the ST...we started to lengthen the pipe. We finally got it to about X plus a quarter inch from plug to beginning of convergent cone and got 38.1 and 38.6 MPH. Each time we lengthened it we picked up a couple MPH. At the final length we already had a gap between header and pipe, and I really did not want to make the gap any larger...so we stopped. I think this pipe needs to be run longer from plug to convergent cone. Would have been interested to add another eigth to quarter inch to the length and see if I could have got over 39 MPH...
This all takes me back to wondering if the STL would be a better pipe for the .18 CVRM...or maybe something between the STL and the ST... Seems one is made for rear exhaust, other is for front exhaust...neither really for a side exhaust. Looks like the STL has a long straight pipe on the header end that could be cut shorter...???
INFO: All speeds taken with an on board garmin GPS receiver.
Sean
PS, them freakin pipes run HOT. Not sure if it was me, or if they are hotter than my original pipe...should have my finger prints back in a couple days...
39 MPH was my best run with my original pipe. This is about 2 to 3 MPH slower than I expected...guess that prop was better than I remember...
I then tried 21ST pipe. Due to its short length it was set at about X minus 1 inch from the plug to the convergent cone. Really could not get the boat on pipe. Best run with this pipe was 29.X MPH.
We then tried the 21SS pipe. We started at a little shorter than X inches...it ran low 30s. Because this was longer than the ST and faster than we got with the ST...we started to lengthen the pipe. We finally got it to about X plus a quarter inch from plug to beginning of convergent cone and got 38.1 and 38.6 MPH. Each time we lengthened it we picked up a couple MPH. At the final length we already had a gap between header and pipe, and I really did not want to make the gap any larger...so we stopped. I think this pipe needs to be run longer from plug to convergent cone. Would have been interested to add another eigth to quarter inch to the length and see if I could have got over 39 MPH...
This all takes me back to wondering if the STL would be a better pipe for the .18 CVRM...or maybe something between the STL and the ST... Seems one is made for rear exhaust, other is for front exhaust...neither really for a side exhaust. Looks like the STL has a long straight pipe on the header end that could be cut shorter...???
INFO: All speeds taken with an on board garmin GPS receiver.
Sean
PS, them freakin pipes run HOT. Not sure if it was me, or if they are hotter than my original pipe...should have my finger prints back in a couple days...
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