Race Logic porting project Vmax twin 600, pics

SamuelJackson

SamuelJackson

Member
Joined
Mar 11, 2006
Messages
133
Age
50
Location
Rovaniemi, Finnish Lapland Europe
After while searching I bought Race Logic templates for my twin. Templates fit fine and instructions are more than good.

It took 3-4 hours per cylinder to do porting by my self.

I have measured this sled by gps based meter for 660 ft s when sled was stock.
Now I going to run it again when jetting is correct.

I let u know how it goes and is sled faster.

Here couple pics how ports changed. I am not going to give any measurements but you get idea what kind ports mods are.

And Yammiegod I think we have to readjust driveline, I`ll ask tips after I know how sled runs.

x3y7h5.jpg


1zgz5hk.jpg


315g75z.jpg
 
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i'm surprised race logic doesn't have you opening up those aux exh ports. that exh port is shaped like my bros vintage exciter and srx and exciter exh ports.
 
Jep I was surprised too that only intake and main exhaust ports must be ported. But on the other hand we have to remember those instructions are for do it your self guys....like me :wink:

And those templates give me courage to take a grinder ....
 
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SamuelJ

What did you use for the grinding, a Dremil and flex drive?

What heads did you find best for the metal removal, a different one for steel, one for the ally?

Thanks
 
1993Vmax4 said:
SamuelJ

What did you use for the grinding, a Dremil and flex drive?

What heads did you find best for the metal removal, a different one for steel, one for the ally?

Thanks
Click to expand...

Double cut burrs are awesome for quick removal on the ally and nicasil. I use them for roughing out and semi-finishing. Also, FYI.....race logic templates always only have you mess w/the exhaust and intake. John @ race logic told me that you never have to mess w/the transfers on todays engines, which I disagree w/totally. Anyhow, they do give you a bigger boost in power from stock, but can still be improved upon.
 
mopar1rules said:
Double cut burrs are awesome for quick removal on the ally and nicasil. I use them for roughing out and semi-finishing. Also, FYI.....race logic templates always only have you mess w/the exhaust and intake. John @ race logic told me that you never have to mess w/the transfers on todays engines, which I disagree w/totally. Anyhow, they do give you a bigger boost in power from stock, but can still be improved upon.
Click to expand...

Did John say why he wouldn't mess with the transfers?
 
toydoc said:
Did John say why he wouldn't mess with the transfers?
Click to expand...

he told me that they flow more than enough for even moderately modded engines. i don't know if i would disagree w/enough flow, but one needs to raise transfers, to set the "type" of powerband on the engine, for the particular engine build being done.
 
I purchased a 97 vmax 600 in 2000 with 800 miles on it. 1 st newer sled in about 10 years at the time. Rode yamaha exciter 440, srv,vmax earlier but then the wife and kid came along not to mention living in the city put a end to my toys. Did nothing to the sled as far as upgrades until I came across this site. Did the thin head gasket and reed notch first. Still looking for a little more I came across PSI pipes and Max Performance cluth kit. PSI are center dumps not the best but helped on the mid range. With that set up the RPM was at 8100 which was where Max/PSI recommened.Ran tough there. Rode with newer 600 triples I was faster. Rode with F7, had nothing on me on the trail. Didnt have the chance to see on a lake but at the time I would have kept the old 600 over the new F7. Rode past many Arti-craps and Ski-donts broken on the side of the trail. Love the reliability!! I knew about the piston pin issue, Made it to 3500 miles before it let go. Tore up one cylinder real bad. I purchase the template from Race logic. Did the porting last year. Only was out once with the rebuild. I did notice quite the improvement. Did take more than expected to jet it. Still dont have it right but Im close. Did other upgrade last year also. Gas shocks all around and a 1 inch Ski-dont track. I know how could I put a Ski-dont track on the yammy but the price was right and it came studded. Had alot of track spin with the stock track! Always spinnig! Track has to many studs (192), Ill be removing some for this year. Hooks up alot better obviously with the track and studs.
With all that said why is the RPM target at 7700-7800? I beleive stock was 7850. After porting and track install my RPM went down to 7800. Only out once as I said but it sure felt like it was shifting out too quick. Im going to reclutch back to 8100. I called Race Logic. The guy I talked with said there shouldnt be a change (increase or decrese) of RPM, stay at 8100. What pipes and other upgrades have you done?
I really enjoy this old Vmax. I have rode some newer sleds from the other manufactures sure the ride is much better for the rough trail but they have nothing over the Vmax on a winding trail ride. The thing is like on rails! If I lift a ski, there is big trouble coming.
 
Thanks its nice hear comments about twin 600, most guys ride triples here.

I am aiming to 7800 rpm because its max stock output there for 97-98 twin.
Here is 98 venture twin dynoed.

http://www.mperformance.se/Grafik/Dynobilder/yamaha/yamaha600/venture00-98/grafventure600-98.jpg

I`ve removed 2 0.19mm thick layer from head gasket to compression back to stock 125 psi reading after porting. I am using stock pipe.

What jets you are running ? I went up two sizes to 153.8

You can read more from this sled here.

http://www.totallyamaha.net/forums/showthread.php?t=62213

Today me and Ike will rebuild clucth and do some testing.
 
Season is opened, first longer run and engine works fine. We had to put more weights to primary.

Set up is now this. Thank you for solving this primary problem belongs to Yammiegod Tony

8CA+3.6g+4.5g and blue-brown-blue with 2 shims.
Engagement 4800rpm

Secondary same:

Green spring 60*
50-40 helix

2h3wkqp.jpg


Video from today.

View My Video
 
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looks fast in the video, sounds a little better to!!!

I soooo jealous you have snow!!! can you bottle some up and ship it to me in Michigan!!! LOL
 
I beleive 155 for mains. Need to go richer yet though. Also richened the needle 1 position.Pilot also needs some work. It will be another month maybe two before I can work on it again. No snow in Wisconsin till late December. Had flurries today. 60 deg. by Sunday though.Anyone know Max Performance part numbers? I have a 6PT7 helix from them. Looking for the angles.Misplaced the info some time ago.
 
denkel said:
I beleive 155 for mains. Need to go richer yet though. Also richened the needle 1 position.Pilot also needs some work. It will be another month maybe two before I can work on it again. No snow in Wisconsin till late December. Had flurries today. 60 deg. by Sunday though.Anyone know Max Performance part numbers? I have a 6PT7 helix from them. Looking for the angles.Misplaced the info some time ago.
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where in wisconsin are you located? press the bushing out of the helix and the angle will be engraved on the bushing bore in the helix.
 
SamuelJackson said:
Thanks its nice hear comments about twin 600, most guys ride triples here.

I am aiming to 7800 rpm because its max stock output there for 97-98 twin.
Here is 98 venture twin dynoed.
http://www.mperformance.se/Grafik/Dynobilder/yamaha/yamaha600/venture00-98/grafventure600-98.jpg

I`ve removed 2 0.19mm thick layer from head gasket to compression back to stock 125 psi reading after porting. I am using stock pipe.

What jets you are running ? I went up two sizes to 153.8

You can read more from this sled here.

http://www.totallyamaha.net/forums/showthread.php?t=62213

Today me and Ike will rebuild clucth and do some testing.
Click to expand...

but, after increasing exh port area, your engine should respond better to a slightly higher rpm than stock. so, your still spinning that thing at 7800rpm?
 
Yes still aiming that 7800. If you increase exhaust port wideness max output rpm wont change, but if you make port higher rpm will increase.

And other thing, if you raise compression max out put rpm will go down, am i right?

I got rpm back to 7800 and sled is now faster at 660 ft anyway.

I ve used this mobile phone program for testing

http://www.racechrono.com/
 
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Mopar I live in Casco (near Algoma) Not far from you. Thanks for the info on where to find the angles. I know its progressive just dont recall the angles.
Just remembered I was jetting too rich last year. Talked to a guy from a Polaris racing family in town here and he got me in the right direction. After porting the engine it doesnt need to be riched, in some cases leaner. I went back to closer to stock jet size and it got better. It was acting like a lean condition which was throughing me off. I cant tell you the jet size with certainty. Ill let you know when I get the chance to play with it again. Dont know about the compression to RPM. What I can tell you is with the twin PSIs and Max Performance clutch set up they recommended 8000-8200 RPM and the thinner head gasket. Still have the set-up sheets if your interested.
Mr. Jackson I see you run an SRV. I beleive I have seen you on Sachs site. I also have an 81 I have been messing with. Did a hack porting job, shaved the head along with a DG pipe. Got lucky with the porting, made a noticeable change in performance. Next is the dual carb setup and dual pipes, If I can find some.
 
SamuelJackson said:
Yes still aiming that 7800. If you increase exhaust port wideness max output rpm wont change, but if you make port higher rpm will increase.

And other thing, if you raise compression max out put rpm will go down, am i right?

I got rpm back to 7800 and sled is now faster at 660 ft anyway.

I ve used this mobile phone program for testing

http://www.racechrono.com/
Click to expand...

max rpms will want to increase, if you increase exh port area at all, even if you don't raise the main exh port. when you widen a exh port, you will pick up more midrange and some upper range rpm/hp, but won't hack as much bottom end away. anytime you raise the exhaust port, you will lost bottom end. as far as raising the comprssion and it hurting max rpms.....increases in compression from stock won't hurt max rpms. you'll see an increase, as hp is increased. maybe if you built the motor to have 16:1 or 17:1 UCCR, you might see the top end over-rev to diminish. you should try spinning that motor at 8100-8200 and see how it likes it.
 
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