Shearer or sniper pipes

[mailman]

The design specs are for 197 exhaust duration and cylinder pressure of 100 atmospheres (a balance of timing and trapped compression). The dyno sheet shows the Sniper to have a broad power curve compared to the Shearer, that means its not peaking at its natural resonance. Being rich, too much timing, compression too high, not enough load and dynoing with a eddy brake can cause this, also gearing and mph on the dyno should simulate the mph as at the track and if two pipes peak at different rpm's, one should have gear added or subtracted to run close to the same mph, so they will have the same engine load.

 

Mailman had some oof drag pipes and did not have time to tune them in, his bike was tuned in close for the Shearer pipe, so he ran them. Those pipes are in the dyno video with the silencers, they are on Brad Painter's bike now and he has won the first four races with them.

 

After running Brad's engine, we realized that the 10 mill cubs are more efficient and are putting off more heat energy than we thought. Now we do not put any venturi or stuffer in the stingers of high output 465's on alcohol. Your Shearers have a 22.7 stuffer welded in the stinger and the Snipers has a 24.5 stuffer, this is one reason why the Sniper's run cooler than the Shearer's and needs less fuel to build heat.

 

The exhaust duration of your engines should not be any problem, they have been tested on engines from 189 to 204 exhaust duration with very good results. The pipes would be a very good match for the 397, try them on that if you don't already have something that will break the record, it will have less intake volume and should be easier to tune with Lectrons.

 

 

Hey Gary,

Do you want me to post up the Sniper vs. Shearer dyno comparison that I did on my Passion 4mil DM? I can list all the specs too if you like.

I am working on a 70 HP gas 350 banshee and was wondering how the Sniper vs Shearers might compare to the T5's on the bike now.

You know me...............always looking for a little more.

 

If anyone in AZ has some inframe Shearer sb pipes or inframe Snipers and would like to lend them to me to dyno test on a 350 then it would be greatly appreciated.

[srp]

Hey Gary,

Do you want me to post up the Sniper vs. Shearer dyno comparison that I did on my Passion 4mil DM? I can list all the specs too if you like.

I am working on a 70 HP gas 350 banshee and was wondering how the Sniper vs Shearers might compare to the T5's on the bike now.

You know me...............always looking for a little more.

 

If anyone in AZ has some inframe Shearer sb pipes or inframe Snipers and would like to lend them to me to dyno test on a 350 then it would be greatly appreciated.

 

Yea, you can post it if you want. Post the 554 vs 492 run also, this will show how broad the power curve gets when the engine is laboring and is not allowed to peak at its natural resonance on the Shearer vs Sniper sheet, if you could overlay the run where the Sniper peaks at is natural resonance making peak power at 10200 would be good too.

 

For the Sniper to be better on a 350, the engine should be tuned to make .23 horse-power per CC or be ran on methanol. Snipers may run very good on the little engines but they may not be the best for peak power on the dyno. On methanol RDZ says the Sniper will out perform all other in-frame pipes even on the little engines, we have not done that test yet on the little engines.

 

Even on small engines where they do not make the most power, they may add performance by accelerating quicker.

[WINDYCITYJOHN400]

[mailman]

There is a ton on information on my hands for this topic so it may take me a while to get all the graphs up and explain them. I worked with 2 different dynoes and 3 different sets of pipes. The bike was run on race gas.

 

The motor in question is a 4 mil DM that Jim built for me. He got the cylinder raw and the cases and did everything he wanted to them. He designed the domes for this motor too. Gary was given this information and designed a custom set of OOF silenced Snipers for this motor. He actually first made me a set of inframes but they wouldn't fit on my Lonestar frame so I had to go the OOF drag pipe route. The Snipers were OOF drag pipes with silencers made for the 554 CC 4 mil DM.

 

I dynoed these at D+M Racing in Glendale on Doug's ATV roller only dyno. The gearing on the bike was 15/41 or 16/41 if I remember correctly which produced speeds of 80 to 85 mph. The first 3 runs were done with the Snipers after I had it jetted correctly for the Snipers. The last 3 runs were some used Shearer OOF non-silenced drag pipes that were hanging on Doug's wall. The Shearers ended up making about 10 hp more than the Snipers with this motor and on this dyno. The Snipers made about 100 HP and the Shearers about 110 HP.

 

There is a ton more info. to this so please wait until I finish posting all the facts up. This may take a few days. You will end up with more questions than answers when I am done. Enjoy.

 

 

Edited July 26, 2012 by mailman

[mailman]

This next graph shows the same motor with the same OOF Sniper silenced pipes on a car dyno at Hall's Precision Motors and this was the best run that we could get which shows 113 HP. The debate on ATV dyno vs car dyno is a topic in itself. Here is the best run with the Snipers on a 554 cc 4 mil DM on gas.

 

[dave5.0]

Edited July 26, 2012 by dave5.0

[mailman]

This next graph is what Gary is asking for I think. It is my old 492 Cheetah vs the 554 DM on Hall's Car dyno. The 554 is the stronger curve. The Cheetah was a 4 mil and 73.5 bore.

I will let you guys chew on this a while. More to come.

 

Edited July 26, 2012 by mailman

[srp]

Chris,

 

If you have the ability to put run 2 and run 36 on the same sheet, it may make it easier to figure out why the big difference in peak power, being the same motor and pipes, the only variable being the dyno ... Thanks Gary

[mailman]

Here you go Gary. This is the exact same setup but on a Car dyno vs an ATV dyno. The car dyno is at Hall's and the ATV dyno is at D+M. Both dynoes are inertia only dynos.

 

Passion 554 cc 4 mil DM motor with OOF silenced Snipers on gas. Car dyno vs ATV dyno. Same jetting, gearing, etc. Just different dyno load.

 

I will show this with RPM on the first graph and with time in seconds on the second graph to show that the car dyno has much longer runs than the atv dyno.

 

 

 

You will notice that the time graph shows the atv dyno run to last about 2-3 seconds for the entire dyno pull and the car dyno run time is about 7-8 seconds long for the dyno pull.

[srp]

Thanks Chris,

 

I would have thought the atv dyno would read higher, what is puzzling is that both dynoes come on the pipe at the very same rpm but peak at different rpm's. All of the dyno runs I have with your pipe peak at 9900 to 10200 and take no more than 3.5 seconds. Very interesting.

[WINDYCITYJOHN400]

I'm confused.....I was looking at your post in the dyno section showing your 465 on gas making 113HP and 62 ft. pounds of torque.

Now looking at this big 554 DM motor I see 113 and only 59 ft. pounds as a best.

Now I know Chris is the king of dyno testing. (He's got quite a few runs over the years.... there are well over 350 at this point.) I think he's made more runs on the dyno per year than runs on the hill.

He dyno'd the snot out of that bike to try to find power in that combo. As you can see he's willing to double check his info on multiple dyno's to verify results. He's so into the testing and tuning that he's dynoing dynos against each other to see how weight differences effect results.

 

But I also know he tests in the real world too. So he has radar runs at the hill to confirm the whole dyno vs. real world results too. (As I recall his hill speeds were very close between the 492 and the 554)

 

I have my own theory as to why the heavier car dyno runs differ from the ATV dyno pulls. I also have some thoughts on why your dyno testing runs ramp up so fast. But I'd sure like to hear your thoughts on these results because he tested his 492 on the same dyno as the 554......so the HP numbers are apples and apples.

Edited July 26, 2012 by WINDYCITYJOHN400

[10milmike]

This thread is creating publicity for all parties involved. Look at the views and posts. Threads like these are the ones that sell products. That's a fact.

Ok all I want is 5 percent of the profit. Lol

[lms1977]

why is a motor passion built with there pipes (554) 4mil dm only making 113hp on race fuel? I thought they would make more ?

[dave5.0]

Mailman im not sure if you're done yet so sorry if you're still adding to this. But this thread is titled shearer or sniper pipes. First post shows shearers making more than the Snipers. Then the rest of them are about the differences in dynos but don't say anything about pipes. So I'm a little confused as to why you're posting all this. Am I missing the point?

[dajogejr]

Mailman im not sure if you're done yet so sorry if you're still adding to this. But this thread is titled shearer or sniper pipes. First post shows shearers making more than the Snipers. Then the rest of them are about the differences in dynos but don't say anything about pipes. So I'm a little confused as to why you're posting all this. Am I missing the point?

 

I think I can answer that... Anytime a dyno or power debate comes up, the source is questioned.

Mailman is giving all the backfill/pertinent information in case the dyno(s) are in question.

 

I'm glad he's providing the info rather than just pulling something out of thin air. I like facts and information to support them.