350x Performance

[userj8670]

What is the best performance exhaust set up for the 350x. Currently I have stock headers with a supertrapp. I know there are cobra and dg out there with larger diameter headers but i was wondering how they compare in terms of performance. Anyone have any tips they care to share?

[Yamaha_Rules69]

A larger diameter header will add a little better performance, because it allows the engine to breathe better by letting the exhaust out faster and more efficently. It may also allow the engine to run a little cooler. Remember with any mod like this to keep an eye on jetting.

[this guy]

Any exhaust worth it's salt is going to require a rejet, and a more efficient intake system. Supertrapp can be tuned, but a friend has looked into XR's only for his 200x and they are making one for him at the cost of one of their standard units. This may be a good option for you, as another buddy of mine runs one on his 2002 XR650 and loves it.

[The Goat]

1.25 inches coming out of the head, and 1.75 to 2.25 inches running to the back.

the silencer is a choice I leave to you!

[andnuaa]

Jim I have a nice complete PK performance plus exhaust for you :naughty:

[lndy650]

for a real power gain PK or have Tom Carlson build you one. The Goats setup sounds like its pretty nice too....

[harryredtrike]

with exhaust bigger is better,but youll need the other things said above to achieve good results

[userj8670]

Jim I have a nice complete PK performance plus exhaust for you :naughty:

I know!! Thanks for reminding me lol! GAH!

[SWIGIN]

this is what i run on my 350rx, it's a aftermarket header (they are all basicly the same) that i shortened the ran 2'' back to my silencer.

[userj8670]

for a real power gain PK or have Tom Carlson build you one. The Goats setup sounds like its pretty nice too....

I have been trying to find Toms contact information. I found a website but i dont think its their official one nor does it have any contact information. I was interested in having them do my motor in the future.

Jim

[SWIGIN]

i have been to his shop....he can be funny to say the least.

[lndy650]

i had a few engines built by Tom one was a 350x 425 bigbore and the other i still have is a 250x bored to 350 built for Nac's. it was raced in 98 and when i got it the crank was getting weak so it just sits for now. he is the best guy to have build your engine that 350 i got has more power than my yfz
his website is http://www.tcracingengines.com/ you have to call him to get any info the site sucks

[userj8670]

Swingin - Thanks for the pic!...i have a NOS pk performance exhaust on its way soon :) Also what would shortening the header do other than making a better fit? So the supertrapp with stock system i should take off soon???lol!!



Indy - How long does it take to rebuild one of these 350x engines? I was thinking something that idles like a harley but has good reliability. Any ideas? Again this isnt something im looking to do now but something Im collecting ideas for. I dont think boring it out to a 425 offers alot of reliability for a trail ride does it?? Like i said something i can trail ride yet also unleash at a moments notice. Kinda like a built up street/strip camaro...everyone knows by the sound its got sac yet its streetable. Hope that makes sense...thanks for the reply!

Jim

[userj8670]

p.s. the website has alot of links that dont do much :(

p.s.s. Indy whats a ball park figure on price for something like that 425 upgrade?

[lndy650]

i bought it like that but when i last talked to Tom i think it was around $500 for a ported head with oversized valves. so im thinkin like maybe 700 for a bigbore and port job. the 350x i have now has a fourstroke tech 452 bigbore and i copied TC's porting on my head. im running a stock cam and ignition right now and the thing wants to pull my arms out of thier sockets. i once rode a 350x that was bored and stroked to a 520 or 525 built by Mickey Dunlap (fourstroke tech). it was almost too much. its amazing what you can do with a 350x engine. i cant wait to finish mine with a custom CDI a Lectron carb and i got a boondocker nitrous kit just laying around...

[userj8670]

Can you take a video of it running? I would really like to hear this thing. What are you running for an exhaust? Im seeing alot of potential here for a build and im lovin it :)

Jim

[lndy650]

ya the website is very annoying

[lndy650]

Can you take a video of it running? I would really like to hear this thing. What are you running for an exhaust? Im seeing alot of potential here for a build and im lovin it :)

Jim

right now its apart i can get some pics inside the beast tomorrow if you want. im doing some more porting and maybe welding up my own high rev cam. im trying to do the impossible and make a high revving 350x engine:naughty:

[lndy650]

my exhaust is just a homemade one for now with a cobra silencer (on a 250x chassis)
but i plan on building a bigger headpipe and use a TC or supertrapp silencer
this is the wheeler the TC350 engine was on(and now my 452) the whole wheeler was built by Nac's :pics:

[jensenracing77]

TC racing number is 814-723-3514. he is one of the best.

[userj8670]

Thanks to everyone that has responded. Yes Indy i would love some pics. Im really pumped to see how your going to grind your own cam. Power to ya! You mention having a high reving 350x...DC made a snotty 200x and i would figure just do the same thing that he did except apply it to a 350x? Mine now is stock and it pulls really well! The other day i was in the backyard just foolin around and i took my thumb off the throttle in second gear to the point where its about to stall and pinned it. The thing reved up about as fast as a drag car and ROASTED the tires...mind you this is all while the bike is still moving and clutch still engaged, I was impressed. Also when blasting along if you get it right when shifting that front tire will be light as a feather :) I can only imagine with work:Bounce :D

[SWIGIN]

Swingin - Thanks for the pic!...i have a NOS pk performance exhaust on its way soon :) Also what would shortening the header do other than making a better fit? So the supertrapp with stock system i should take off soon???lol!!



Indy - How long does it take to rebuild one of these 350x engines? I was thinking something that idles like a harley but has good reliability. Any ideas? Again this isnt something im looking to do now but something Im collecting ideas for. I dont think boring it out to a 425 offers alot of reliability for a trail ride does it?? Like i said something i can trail ride yet also unleash at a moments notice. Kinda like a built up street/strip camaro...everyone knows by the sound its got sac yet its streetable. Hope that makes sense...thanks for the reply!

Jim



if you just want a stout running trail motor build a 10.25-1 motor with a megacycle full race cam with HD springs and hardened rockers, a GOOD port job, and an old PE 38mm round slide carb.

this is a great all around motor that'll run for years and years.

if you search my threads i started you'll see my ascot head swap thread.....might show you alittle of what's involved in a major build.

[lndy650]

whats the advantages to an ascott head compared to a ported 350x head with oversize valves?

[lndy650]

:pics: http://www.3wheelerworldforums.com/showthread.php?p=792835#post792835

[The Goat]

all credit to swigin for dealing with my pestering as i asked questions about the exhaust.

The exhaust is his idea until it tucks back into the frame...then it's a little creative. PICS DECEMBER 13

[userj8670]

if you just want a stout running trail motor build a 10.25-1 motor with a megacycle full race cam with HD springs and hardened rockers, a GOOD port job, and an old PE 38mm round slide carb.

this is a great all around motor that'll run for years and years.

if you search my threads i started you'll see my ascot head swap thread.....might show you alittle of what's involved in a major build.



http://www.youtube.com/watch?v=640kn-_bEYA I found this video and it is kinda what i had in mind in terms of a machine. Its got a noticable idle and you can tell by the sound its got work done. Now is this something that could still be reliable and trail worthy? Thanks!!:)

[lndy650]

i have about 6 hours on my 452 which isnt really much but its in great shape inside.(i started with a new old stock engine) the main problem is with a big bore like a 452 there is much less meat on the cylinder and they can overheat. there is an awesome oil cooler on ebay that dumps cool oil into the valve cover. i think with a stock or mild cam they are very trail worthy. my TC425 had tons of miles on it with a radical cam the valves were wore to nothing and it still had balls

[SWIGIN]

whats the advantages to an ascott head compared to a ported 350x head with oversize valves?

ascott valves are still bigger and the ports are bigger then TC ever made 350x ports, and the head is made to work with the piston im using. so no more custom parts or gasket cutting.

plus....i just wanted to kill all the rumors on how easy it is to get one to fit.

[lndy650]

it is a very impressive build. i too hate the rumors like a xr 500 piston and sleeve will bolt right on i heard that then found out the hard way you need to shorten the rod...

[The Goat]

but how do the damned things RUN

[lndy650]

my 425 friggin ripped! my 452 with stock porting had more power than my yfz on lowend but not much on top which is why im porting it now. id like to hear more on SWIGIN'S stroker

[SWIGIN]

well, mines not done or going to be done for a long time.

my buddys (2 of them) have built the same motor minus the ascot head, both 460cc motors are in quads and run REAL good.

both will run away and hide from built 450s....it's a beautiful thing!

[lndy650]

yes it is abeautiful thing! i love these old air cooled thumpers!!