Stock header mod

I have read about grinding out the excess material on the stock header where it connects to the engine on other forums to increase exhaust air flow. Any of you guys tried this? If so I would like to here if it made much difference in HP and or tork.

Opening up that very restrictive stinger (Silencer end cap) will yield a noticable gain.

I'm doing mine this weekend and I will let you know.

Smoothing the flange weld will help, but you won't get a seat-of the pants result.And I'm not sure it is even a problem on the 450. I know the 660 header has some dirt-dobb'in inside them.
A tip is a good idea, but word of warning, a lot of the tips sold on E-Bay are 1-3/4 don't buy one of those,make sure it is a 1-1/2. 1-3/4 is too big for a mostly stock motor, you will loose much-needed back-pressure. Dyno results show 1-1/2 gets the most gain, 1-H.P.
Jimbo

Quote :

A tip is a good idea, but word of warning, a lot of the tips sold on E-Bay are 1-3/4 don't buy one of those,make sure it is a 1-1/2. 1-3/4 is too big for a mostly stock motor, you will loose much-needed back-pressure. Dyno results show 1-1/2 gets the most gain, 1-H.P.

Jimbo,
Where did you get the data about the tips..?.Weve tried several differant senarios and have yielded the most power on a stock motor with a 1-7/8 Id tip that is flush on the inside. Better Bottom ,mid and top. As a matter of fact it freed it up so much that I had to rejet his carb. .025 washer under needle, 2turns out on low speed adjuster and 160 main.Another kid that hangs around our shop has FMF duals on his rhino and it wont get out of its on way..Sounds good ,but slow as turtle shit, even with an aftermarket nonvaccum carb.
Vince
http://georgia4x4.madmooseforum.com/viewforum.php?f=7&sid=8e6b72594875b4fa70eb1784db896cca

The hole thru the baffle plate only looks like 1.25" so I would think any sizes above that would be a plus no matter what the size? Am I thinkin wrong?

No your not thinkin wrong...It is just this, what was stated is that anything above 1-1/2 ID would "lose much needed Back Pressure"..I would like to see this data. We know for a fact that it does not... On the flip side though ,dual exhaust double 's the opening size with one tube per exhaust valve. The dual exhaust systems that I have seen ,make a good sound, but they dont acctually increase the exceleration and overall power over a stock exhaust with flame arrestor removed and a 1-5/8's to 1-7/8's ID tip.......
Vince

I Agree. I've got the 1 7/8 ID tip. Got the RAIS intake, UNI replacement filter, swapped washers on needle, 157.5 main Jet, and A/F screw out 1 7/8. My Rhino is running awesome. noticeable low thru midrange power, and a solid 2MPH increase on top end. Smooth all the way thru the powerband. no stumbles what so ever. I'm very happy with the results of the Carb tuneup.

GA 4x4 since you seem to have knowledge on this area i got this tip on mine your thoughts?

http://www.hunterworks.com/inc/sdetail/807

that is what yall are talkin about right?

shawnley1222 wrote:

GA 4x4 since you seem to have knowledge on this area i got this tip on mine your thoughts?

http://www.hunterworks.com/inc/sdetail/807

that is what yall are talkin about right?

Yea, thats it. But I got mine on Ebay for almost $20.00 cheaper. Got mine here...................

........ http://cgi.ebay.com/ebaymotors/POWER-TIP-YAMAHA-GRIZZLY-660-450-400-RHINO-EXHAUST_W0QQitemZ230217145719QQihZ013QQcategoryZ43978QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

well i got my cdi tip and sheave as a package deal thats just the link for just the tip

Thats it...We just modifiy the stock one.That one looks good...

I'm not sure on the size of it but it looks nice and sounds ALOT different and couldn't tell you how much difference since i did my cdi sheave and tip all at once sorry cant add to that part of the thread

Georgia4x4 wrote:

Quote :

A tip is a good idea, but word of warning, a lot of the tips sold on E-Bay are 1-3/4 don't buy one of those,make sure it is a 1-1/2. 1-3/4 is too big for a mostly stock motor, you will loose much-needed back-pressure. Dyno results show 1-1/2 gets the most gain, 1-H.P.

Jimbo,
Where did you get the data about the tips..?.Weve tried several differant senarios and have yielded the most power on a stock motor with a 1-7/8 Id tip that is flush on the inside. Better Bottom ,mid and top. As a matter of fact it freed it up so much that I had to rejet his carb. .025 washer under needle, 2turns out on low speed adjuster and 160 main.Another kid that hangs around our shop has FMF duals on his rhino and it wont get out of its on way..Sounds good ,but slow as turtle shit, even with an aftermarket nonvaccum carb.
Vince
http://georgia4x4.madmooseforum.com/viewforum.php?f=7&sid=8e6b72594875b4fa70eb1784db896cca

Here ya go.

http://www.ridesidebyside.com/forums/showthread.php?t=4014 I take what Todd says over what anybody else does. He does the research on a dyno and doesnt spew fiction like a lot of folks.

Thanks for the link.
I called Hunterworks and challenged them on there tip size recomendations. I also asked them how could you make this a valid point .Are the pipe companies ripping everybody off with their dual exhaust systems then.?.Two pipes, two silencers ,got to flow alot more than a two into one unit right...? I then asked them what kinda of Dyno they had, we have had a "Land and Sea" Dyno here that we tested Kart, Bandolero And Legends car engines on ,and I am somewhat familier with the terminology...They could not even tell what Dyno they had...You make the call.

Todd has ALWAYS been honest with me!! and the stuff he told me to put on my rhino worked..

Georgia4x4 wrote:

Thanks for the link.
I called Hunterworks and challenged them on there tip size recomendations. I also asked them how could you make this a valid point .Are the pipe companies ripping everybody off with their dual exhaust systems then.?.Two pipes, two silencers ,got to flow alot more than a two into one unit right...? I then asked them what kinda of Dyno they had, we have had a "Land and Sea" Dyno here that we tested Kart, Bandolero And Legends car engines on ,and I am somewhat familier with the terminology...They could not even tell what Dyno they had...You make the call.

You my friend obviously didn't talk to Todd. Don't get your feelings hurt man.......Some pipes in fact do perform worse than the stocker. The same goes for some tips...period. I'll make the call don't worry, it dang sure won't be to ga4x3-1/2 .

To each their own I always say!

"Another kid that hangs around our shop has FMF duals on his rhino and it wont get out of its on way"


Humm contradicting yourself huh???? Guess your tuning skills arn't what you claim.... Neither are your fab skills, here's an example. Why in the world would you weld a rear-bumper to your FRAME at the a-arm mounts?????? As flimsy as they are, the first time you get hit in the rear whats gonna happen????? YOU WILL BEND YOUR FRAME.....I'm done.

Hey, Facts are facts.You and your buddy were the ones that stated that anything over 1-1/2 id was to much..On the other statement you made, You obviously did not read the entire post with that picture stating that it was only 90 percent done. Both arms are tied together with 1-1/2 .093 dom tubing..Do you know what that is..? I doubt it, they dont build bolt on parts like that do they..Thats alright, hey yall ride around on your dirt roads and play in the mud ,we race .

Picture from todays practice...bring your week shit down here.We've won more races than you've been to..

Just kidding......
Vincel

edit

When and where...?

Waiting...

Ok, Bottom line is this. With a Stock Rhino Motor, Maximum Performance will be acheived for less than $500.00. RAIS, Tip, Rejetting, CDI,Sheave. Thats it. 58 MPH and Better low to midrange pull. Any Increase after that comes at a very high cost per H/P, and MPH, Both in Money and sacrifice in trailability. Dual exhausts for what they get you are a tremendous cost, and in a stock motor, a waste of your money. So is a aftermarket carb. If you want to really improve your Trailready Rhino, spend the $1200.00 on good shocks instead of an aftermarket pipe or Carb. If you want to Race them Competitively, get ready to pull out your wallet. If not, stop after the $500.00 and save your money.