JE 13:1 PITONS

[MAD MAX]

HOW MUCH HORSEPOWER GAIN WILL YOU GET OUT OF THE (JE 13:1 81MM PISTONS)?I WAS THINKING ABOUT PUTTING A SET IN MY BIKE.THATS JUST THE PISTONS THERE SELF WITH OUT CAMS.I WOUID LIKE TO HAVE CAMS BUT THE WALLET JUST CAN'T HOLD ALL THE PRESSURE.THE BIKE RUNS GOOD BUT I NEED MORE.IT RUN BETWEEN 6.20 AT 118 TO 119 WITH A 175 POUND RIDER.WHAT DO YOU THINK I CAN OUT OF HER WITH THESE PISTONS.I WOULD LIKE TO HEAR WHAT YOU THINK.THANKS LOL

 

[Mr. Busa]

Is this a 1397 kit?

 

[MAD MAX]

NO IT'S A STOCK PISTON BORE WITH 13:1 COMPRESSION.YOU USE THE STOCK CLINDERS AND RINGS.THATS WHAT A 81MM IS IT'S THE STOCK PISTON SIZE.

 

[Landspeed Larry]

Stock compression ratio is 11-1 so the added compression would be good for about 8 HP. Benefits accrue with improved mapping. Worth doing and won't affect the bike negatively as you can still use pump gas. You might play with gearing also.

 

[MET]

If you were to go to all of the trouble to replace the pistons I would go with a bigger bore. You said you were looking for HP. Or find other ways to increase hp. Even dry NOS will get you 20-40hp pretty safe.

 

[MAD MAX]

I KNOW I CAN MORE OUT OF A BIGGER BORE BUT I CAN GET THESE CHEAP.THATS WHY I WOULD LIKE TO KNOW HOW MUCH HP THEY WOULD MAKE.

 

[sven]

whatever suits you-

but if you are going to replace the pistons you might as well put a big (bigger) bore kit in there as well.

having trick parts is fine but there is

" NO REPLACEMENT FOR DISPLACEMENT" .

 

[200hp]

Take the jugs off
Remove the base gasket                                          (free)
mill the head .010                                                   ($50)
buy a stock intake cam and stick it in the exhaust side ($100)
buy APE adjustable cam chain sprockets                     ($65)
You will get a lot more out of it then you will get with those heavy pistons.  

Mine makes 200 hp and 113 lb-ft of torque.  
I keep finding more little things that help

240 with the medium dry shot jet.  

IS THAT ENOUGH FOR NOW?

 

[200hp]

Bam!!!

 

[jwcfbd]

They need to keep that dyno away from the coffee it has a serious case of the jitters

Nice numbers hang on tight.

 

[200hp]

Ok I had to turn smoothing off to get 200. It made 197 with smoothing maxxed out.

 

[cabito85]

200Hp,Didyou get 200hp onlywith a cam, milled head and base gasket removed???Its amaizing!!!!

 

[sven]

high flow air filter and full race exhaust? my '99 busa is euro spec and made 175 hp stock. Probably makes at least around 190 (inc ram air)

 

[200hp]

It has 2 intake cams, and no air filter also.

 

[sven]

oh

 

[CoolBUSA5454]

You guys keep using that dry system and you'll melt those pretty pistons...

 

[gixxer1300r]

You guys keep using that dry system and you'll melt those pretty pistons...

I have seen more motors nuke on wet systems than dry