SV vs. TZ Question

[ecumike]

....Then some hotshot rider would take a 62hp bike like superducks and rail the whole gtl crowd...

Soooo you're saying there's a chance.

My priller (supposedly, per Aprilia) puts out ~62 HP, but I can't seem to rail the GTL crowd :(

But maybe that's b/c I'm not as good as Roach.
In a few years, hopefully...

[Super Dave]

The thing about running leaded fuel on a 97+ year TZ is that you have to advance the static timing on it quite a bit and run higher compression heads and/or run positive deckheight do get any kind of grunt out of the motor. The problem with this was that the leaner I went .. more detonation I would get. So it was always safe and cheaper to sacrafice a few horsies and run  two or so sizes rich.

Do you want to run an Unleaded Racing fuel?  I have some.  Well, not today, but I've had it around quite a bit.

You thought about having the heads recut?

Aprilia RS250's are not TZ's.  It's still a street bike with 62HP.  They are fun, and you can learn a lot.  But it's not a "race bike".  I think there is still a chance though.

[TZDeSioux]

Do you want to run an Unleaded Racing fuel?  I have some.  Well, not today, but I've had it around quite a bit.

You thought about having the heads recut?

quote]

I like running leaded fuel. It has natural lubricating qualities due to the lead content. It's easier on the parts and makes more power too. I doubt I'll get the 03 heads recut. Probably try out a few things when I first run it. Advance timing and run really thin base gaskets and see what happens.

[Monty925]

Have you spoken to anyone about how much deck height to run on your '03 and what timing to try?

We work with Todd Bowman at Swedetech and have had nothing but positive results.  

Since you are in another region and I won't have to race against you anytime soon I'd be happy to share tips. ;D

Just tryin to help a brother out...

[Super Dave]

I agree in ways.  I think unleadeds  :-X

I haven't really looked inside the new TZ's though.  Advancing the timing will give it grunt off the bottom, but ruin the top.  And it will cause some pain in the bottom end.  Oh, and heat.  

I imagine it has something to do with the shape of the combustion chamber, obviously.  

Are you advancing the timing based on the pistion's distance from TDC or just advancing it on the crank?

[TZDeSioux]

Have you spoken to anyone about how much deck height to run on your '03 and what timing to try?

We work with Todd Bowman at Swedetech and have had nothing but positive results.  

Since you are in another region and I won't have to race against you anytime soon I'd be happy to share tips. ;D

Just tryin to help a brother out...

I'm basically going at this all blind so any help you might be able to provide will be appreciated. Did you have swedetech work on your motor right away or were you able to run it a few times stock? If so.. what were the results? I assume since both your bike and my bike have the 54x54 bores whatever deckheight and timing you set yours at before the build should put me in the ball park. By the way.. congrats on your WERA national championship.

[TZDeSioux]

I agree in ways.  I think unleadeds  :-X

I haven't really looked inside the new TZ's though.  Advancing the timing will give it grunt off the bottom, but ruin the top.  And it will cause some pain in the bottom end.  Oh, and heat.  

I imagine it has something to do with the shape of the combustion chamber, obviously.  

Are you advancing the timing based on the pistion's distance from TDC or just advancing it on the crank?

Well running leaded fuel with the standard timing with the standard heads will give me alot of over-rev but nothing at the bottom. I think advancing the timing will give me atleast some useable power at the bottom to mid. With the deckheight doing the same. When I advance the timing, it's done based on the piston's distance from TDC. On my 98.. the stock setting was 1.7mm TDC. I would change it anywhere between 1.95mm-2.1mm depending on the situation. Obviously at a track like Road America, I'd go with the 1.95mm timing.

[TZDeSioux]

OH yeah... since USGPRU will be running 250 class in 2004...it will probably be a good idea to keep the bike unleaded anyway since they will go by the FIM rules.  ::) So I really doubt I will get the heads recut unless it comes with spare heads.

[Monty925]

"Did you have swedetech work on your motor right away or were you able to run it a few times stock? If so.. what were the results? I assume since both your bike and my bike have the 54x54 bores whatever deckheight and timing you set yours at before the build should put me in the ball park."

The motor had the full Swedetech treadment prior to my purchasing it.  Bill Oprendek did an outstanding job of setting it up, I just stick to my set up notes and the bike is very reliable.  Moderately quick too.

I do have cut heads, two different volumes and the cylinders have been shaved too.  Email me at Montyw2@aol.com for more detailed info.

[Super Dave]

The guys that I knew that were really doing well with 250's always at least took them down before ever running them.  Just to go through and remove the flashing and make sure everything looked ok.

Monty, are you running an unleaded?  I think it's a stupid rule for racing in the US as so few fuel manufacturers are making decent unleaded racing fuels.  The BTU's are just not there.  And, under CCS rules, the way they are written right now, they are not legal.  Neither is pump gas.  They are not enforcing them either.

Seems like I've heard TZ timing being pretty good at about 1.8 or so.  You've got some serious advance there.  

[Monty925]

I run leaded Nutec GP-2.

On the 2000's and newer stock timing is in the 2.4-2.5 range.

We run mostly the 8.5cc heads, some positive deck height, 30:1 mix ratio with Castrol 747 and Jolly Moto Pipes.  They are the easiest bolt on HP you can get for the TZ.  JM's are good for almost 750-1000 more rpm.  I have the Yamaha Kit pipes and stock pipes, they both rev to about 12,5. The JM's go well past 13,2 through 4th gear.

[Super Dave]

Wow, that seems like a lot of timing.

Why so little oil, 30:1?  I do love the smell of A747 in the morning.