21 outboard pipe whats the best one and where to get it

[Chris Wood]

The cooper pipe went out of production because it was costing them THOUSANDS of dollars to make them. They had dies made and was having them stamped out and the people stamping them wanted huges runs of them that they could not afford to have done then they had to turn around and weld them. It was a loosing situation. And if you asked lynns son they didnt think the pipe was that good anyway

 

[LarryConrad]

Find the right length on a Cooper outboard pipe and its visually a night and day difference over the Irwin stamped and the Silver bullet HP. I've witnessed it first hand on both my CMB RS and Premo's Nova when he originally switched from the Irwin stamped pipe to the Cooper.

I've yet to see the SPP RS pipe that many have recommended. Does anybody have picture of it that the could post on here?

-Jr.

SPP RS pipe

 

[TUNLBOTR]

With the cooper it was hit or miss with the pipe. I had one (cooper) that was SCARY, and its in Riverview, off buoy 5. The next one, from Mic, didn't have as rad a powerband. I have another that hasn't been tested, one of Lyn's different stinger config.'s. The Irwin is a proven killer, hTb sb is a great option.

 

[cooperpipes]

SPP NRS 21Pic from Ozspec hobbies,

Gene

Why did the Cooper 21 outboard pipe go out of production?

Just wondering

The Cost was high but the biggest reason was the casting that was being built for us was not consistent with are specifications so the pipes where not always the same in peformance.

 

[jaxracer]

SPP NRS 21Pic from Ozspec hobbies,

Gene

Why did the Cooper 21 outboard pipe go out of production?

Just wondering

The Cost was high but the biggest reason was the casting that was being built for us was not consistent with are specifications so the pipes where not always the same in peformance.

Well the ones that did work, worked extremely well. Is there anyway that they could be produced in a stamped version using the same specs or even made as a spun piece like how the inboard pipes are put together? The pipes were awesome and I know most everybody would love to have them back on the market and available if possible.

-Mitch

 

[dave roach]

The alum section need to be casted that way they would be all the same.But die casting is not cheap.The die for that would be around 100k or more to make.I know the ones Steve had made are sand casted and are not all the same.

Dave Roach

 

[cooperpipes]

The Last time we checked in to having another company build them they wanted 50k and a mim order of somthing like 5000 pieces you fellows would have to buy alot of very expensive pipes up front

HA HA

If the price was right we might look into it

Lynn

 

[jaxracer]

Is the cast bend really that important to the performance of the pipe? If not, then wouldn't a stamped version be relatively cheap to make?

 

[LarryConrad]

I sent Mark a email,I just hate to invest in several pipes and hundreds of dollars and end up using one pipe. I may try to find some early Cooper pipes<inboard and do some hacking

Mike pipes are like props, you can never have too many.

 

[cooperpipes]

The Last time we checked in to having another company build them they wanted 50k and a mim order of somthing like 5000 pieces you fellows would have to buy alot of very expensive pipes up front

HA HA

If the price was right we might look into it

Lynn

Ouch i see why your no longer making them

ill check up with a guy that might be able to help

Greg

Let me know what you find out

Lynn

 

[moparbarn]

Is the cast bend really that important to the performance of the pipe? If not, then wouldn't a stamped version be relatively cheap to make?

yes, the bend also included the divergent cone. kinda important to the performance of the pipe ..............

 

[RonShaw]

Can anyone say "Equi Pipe"? Still my favorite even though I really havent tried most of the pipes on this thread as they came out in the last 16 years.......

 

[moparbarn]

another great ob pipe, ron. still available as the "equalizer" (i believe that's the right name) from bob kensill/krpnova here.

 

[jaxracer]

Talking tuned pipes, here is yet another enlightening post by Jim Allen. This was taken from the hydro forum "Gas props on a nitro rigger."

"There is enough dyno tested information on the web about tuned pipes to make the following observations. The material selected for the construction of whatever pipe will greatly effect its performance. Aluminum is the worst material to be used followed by mild steel, stainless steel & titanium. Coatings & various wraps will help with materials that have high thermal conductivity. Poor exhaust duct design & head pipe design cannot be erased with a good pipe design. Both the exhaust duct in the engine & the head pipe must be tappered. Straight head pipes, even those made with larger diameters will always result in decreased HP. Tuned pipe volumes when compared to the engines displacement should be at least 32 times greater. Stinger lengths should be 13 times the stingers inside diameter to be effective.

Jim Allen"

 

[topfuel443]