Super Jet EPIC Dyno Testing

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QJS

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As promised some footage from our day on the dyno with EPIC.
Not the worlds best video, we were a bit disorganised due to the last minute opportunity but hopefully you find it interesting at least.
I can't take credit for the engine, just involved with the ignition side. Also please remember this is a race engine.
I have lots of data so any questions just ask.
Chris

 
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masterblaster

masterblaster

X-H2
great to see you putting in the research with the epic,the dyno must have had a serious load on it,for it to be taking so long to rev out,can you post the power curve the dyno displays hp at given rpm through out the range. Are you doing this test with a b pipe as well?
 
ATS_Aaron

ATS_Aaron

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Awesome, thanks for posting that.

EDIT - Oh yeah, can you post the full dyno run info? I'd like to see the rpm vs hp results. Just curious on the power band.

Aaron
 
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Waternut

Waternut

Customizing addict
Location
Macon, GA
I've never seen a jetski engine on a dyno but it sure seems like the engine isn't running right. I realize the engine is under heavy load but just sounds like it's bogging until the carbs clean up and then it shoots to max rpms. I've heard lots of good things about the EPIC and I know you had nothing to do with the engine so don't take any offense.
 
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masterblaster said:
great to see you putting in the research with the epic,the dyno must have had a serious load on it,for it to be taking so long to rev out,can you post the power curve the dyno displays hp at given rpm through out the range. Are you doing this test with a b pipe as well?
Click to expand...

I don't have the graphs but I do have some tables, I can't post anything as its done on a bubble jet printer and I can hardly read it but I'll have a look through and post some numbers up later. Yes the engine is loaded, in fact the one place you don't stand is near the couplers because they fly apart sometimes.
The fact that you can hear every flaw in the engine is almost as useful as the results on the screen, its so easy to tell when you go lean or rich. We didn't get any deto on this engine at all but when you do its just so easy to hear.
Chris.
 
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Waternut said:
I've never seen a jetski engine on a dyno but it sure seems like the engine isn't running right. I realize the engine is under heavy load but just sounds like it's bogging until the carbs clean up and then it shoots to max rpms. I've heard lots of good things about the EPIC and I know you had nothing to do with the engine so don't take any offense.
Click to expand...

Yes you do hear quite a lot of bogging, this is after the engine has just been started, its takes a while to get the fuel through because the tank is a long way off and quite a bit lower than the carbs, once dialled in we could leave it idling for ages, hit the throttle and the engine would go to max rpm perfectly clean. On the water the rider was struggling to keep the front down for a race start.
Chris.
 
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Boris said:
Very impressive.

Any jetting changes between runs ?
Click to expand...

There was a high speed jet change while the OEM CDI was fitted. After EPIC went on no jet changes just richening the carbs when we advanced the timing more.
Chris.
 
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Here's the ignition curve we ended up with. Except the final timing from 7000rpm on was 15* not 17*.
 

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ATS_Aaron

ATS_Aaron

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Shady Shores, TX
steve-uk said:
hey chris what were the specs on the motor, just a straight up 701?
Click to expand...

Ported 61X cylinder (didn't' specify the bore) and +5mm stroker crank.

Seeing that video is killing me. We've got to get our dyno working soon. We have a jig to allow us to bolt it to the back of the pump after you remove the reduction nozzle and tail cone, but it needs some machining so we are at the mercy of our machine shops busy time schedule. I am excited and yet a little scared to put my motor on the dyno. I'll probably start with the stock SJ I built last fall just to get the hang of the operation.

Aaron
 
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QJS

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Its a 62T engine with a 61x flywheel. Other specs are 5mm stroker, 82.5 bore,3mm spacer under the cylinder, 48 thou squish, pump gas, twin stock 44mm mikunis with a stock 62T manifold that has been modded.
Chris.
 
augustaf

augustaf

Location
central florida
QJS said:
Its a 62T engine with a 61x flywheel. Other specs are 5mm stroker, 82.5 bore,3mm spacer under the cylinder, 48 thou squish, pump gas, twin stock 44mm mikunis with a stock 62T manifold that has been modded.
Chris.
Click to expand...

Have not tried an epic with a 61X stator , other than a timing change, is the spark as strong as with a 62T? Any other differences noted? I trust the modding of the 62T manifold entailed blocking the crossover?
 
92sj

92sj

Location
maryland
ok i maybe way off with this but how well would this work on a 760 with 62t electronics
 
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