50mm TB and Green injector

DuneDevil · #1 (**permalink**) 12-08-2010, 07:52 PM

OK, here is a question for those that have dynoed before and after.

All things done to the bike that can be done, bolt on wise. New full exhaust, intake ring and filter, race ecu, FMI. The bike screams!

Will a new 50 mm TB and New Green injector increase horsepower, or move the curve up in the power band, or be a waste of money until a big bore and stroker are installed?

I know a few of the big names on here have tried this, and would like to here what they say about this. In my theory, if the bike is running perfect with the stock injector, then it will not gain anything going to a larger injector....... Am I right? But, with a larger TB, could you see a increase?

Thanks

DuneDevil

JH Racing · #2 (**permalink**) 12-08-2010, 08:52 PM

I dynoed a bike w/ ported head,ex cam,piston,ecu,green injector,and filter ring The difference in the stock throttle body and 50mm was 1hp and about 1.5 tq but on the track I ended up putting the stocker back on

DuneDevil · #3 (**permalink**) 12-08-2010, 09:32 PM

Quote: Originally Posted by JH Racing

but on the track I ended up putting the stocker back on

Can I ask why you put the stocker back on? Did it loose low end power?

The bike that I am talking about, also has a ex cam. Like I said, this bike screams, but always curious if more can be made......

Thanks for responding!

DuneDevil

cook78ltr · #4 (**permalink**) 12-09-2010, 12:26 AM

Quote: Originally Posted by DuneDevil

Quote: Originally Posted by JH Racing

but on the track I ended up putting the stocker back on

Can I ask why you put the stocker back on? Did it loose low end power?

The bike that I am talking about, also has a ex cam. Like I said, this bike screams, but always curious if more can be made......

Thanks for responding!

DuneDevil

+1 ?

I mean I don't run the team 50mm, mine are custom but I gained 2 horse and 2 1/2 ft lbs. I wouldn't take it off? It made more power from top to bottom.

JH Racing · #5 (**permalink**) 12-09-2010, 09:53 AM

mine lost torque on the track

TNT · #6 (**permalink**) 12-09-2010, 09:24 PM

Quote: Originally Posted by cook78ltr

Quote: Originally Posted by DuneDevil

Quote: Originally Posted by JH Racing

but on the track I ended up putting the stocker back on

Can I ask why you put the stocker back on? Did it loose low end power?

The bike that I am talking about, also has a ex cam. Like I said, this bike screams, but always curious if more can be made......

Thanks for responding!

DuneDevil

+1 ?

I mean I don't run the team 50mm, mine are custom but I gained 2 horse and 2 1/2 ft lbs. I wouldn't take it off? It made more power from top to bottom.

Is yours a straight bore or did you have it machined to a conic? Also if you don't smooth out the bend in the intake manifold, use a larger filter, better air duct and make it all flow right to the right port job a larger TB and injector won't do much good. Also air is a weird cookie what works on one quad, atomosphere, dyno, track may or may not on others.

JH Racing · #7 (**permalink**) 12-10-2010, 10:23 AM

The head and tube I had came from rage. The throttle body is from the brp race dep. BCS filter ring w/ foam filter all bases were covered. I am working on some other things now so I will try again later

TNT · #8 (**permalink**) 12-10-2010, 02:37 PM

Few things I can suggest is there is a nasty bend in the manifold that will create some turbulance, if I remember right is a welded tubing at like a 45 deg bend. Also in theory the TB will respond best to a taper, smaller at the output larger at the intput. I think someone said out here the BRP does this? I'd be interested if someone can mic it. It have to machined with a cone cutter.

The ring is not the most effective design but gets through the box, a better design would eliminate the ring and attach directly over the filter flange like FCI eliminating some turbulance. If your running the stock rubber boot ducting not good. I doubt one sees much gain from a 50mm TB since the air input is to unstable. Hard plastic is best or sheet metal that will reduce expansion and contraction and boundry layer turbulance. Keep the air tract straight and parallel to the ground, look for any other obstructions where turbulance may occur. From the filter the air is a converging(down) duct through the TB to the port to drop manifold vacuum pressure and increase velocity to atomize fuel faster and provide manily more torque, to make best use of the TB and this overall shape an epoxied down port is ideal. If you look at the air intake track system as a whole, a broken detail link can effect overall performance.