Tri-Z first time at the 300ft Sand Drags.. How did I do?

[EK-Racing]

Hey, Ive got an 85 Tri-Z and took it to the sand drags last weekend to make a few passes for the first time. First and foremost it was a blast. I was wondering what these bikes are supposed to run and based on my mods if my bike is running good or bad. Here's the run down.

85 Tri-Z
Stock Pipe, DG silencer
35 mm PWK Carb
K&N filter in stock air box, w/ lid removed
Wrench Report Porting. Exhaust port raised 1.75 mm, Boost port added.
Head milled 0.025
Wiseco +0.50 mm Piston
14 tooth front sprocket
Ran with two different tires. bald 20" Ohtsu Radial Knobbies and 22" 8 paddles.
Now the bad part , Im 6'-3" and 265 lbs...

Well best pass with 20" baldies was 6.07 at 55 mph
Best with 22" Paddles was 6.22 at 52.4 mph

Lost alot of MPH with those big paddles.

I could not make use of the paddles, bike wants to wheelie with either tires. Could only pull 2.2x 60fts with both tires.

Are those times ok, based on the mods and my weight?

The Bike. Yea, Im missing the rad. shrouds
http://i585.photobucket.com/albums/ss291/power302/IMG_0119.jpg


Eric

[beetle5150]

in my experience, a 6 second bike is pretty good. obviously you want faster, but that will come with time, experience, and setup.

[RIDE-RED 250r]

Trikes are VERY tough to drag race unless you stretch em! Especially when racing quads.....

On loose gravel I can launch mine pretty good. But every time I have ever dragged against others (always riding quads) it's on grippy surface.. Mainly a mix of grass and hard pack. I start out with my bean-bag practically on the fuel cap and it still wheelies like a sum**** in up to 3rd. That was with my old setup. Haven't tried since I 350-ified my R..

[4x4van]

The fastest way to start on a trike when you have good traction (paddles in sand) is to sit your ass at the back of the seat, then at the split second before launch, throw your weight forward and drop the clutch just as your weight "hits" the front. I've been using this technique for hill racing at Glamis for years, and no other technique comes close.

I can start in 2nd gear (1st is a complete waste for racing), with Skat Trak paddles, wide open, without wheelies (stock length swinger) every time, and nearly immediately hit 3rd gear. I'm hitting 4th gear at the very base of the hill (start line is typically 20-25 yards from the base of the hill), and 5th gear less than 1/4 of the way up the hill. Depending on the hill (steepness, length), I can usually pull that over the top, although sometimes have to drop back to 4th gear 3/4 of the way up.

Throwing your weight forward just that split second before launch does 2 things; it helps to plant the front end and avoid wheelies, and it helps to get some momentum going to start the bike moving forward. Try it; it takes a bit of practice to get it right, but once you do, you'll be leading your competitiors by 1-2 bike lengths within the first 20 feet of the race. Then they have to play "catch up"!!!

[RIDE-RED 250r]

Very interesting 4x4... I never thought of trying a method like that. I'll give it a try sometime. :beer

[Bryan Raffa]

Not bad for what you got!

[bkm]

Not too bad for the first time. I used to run my basically stock piped '86 250r and with a 20" paddle I ran 5.7-5.8 all day long and a good launch would get me a 5.6 every once in a while. I switched to a ESR 310 cylinder and ran a 5.3-5.4 with a stock swinger. It was hard to get a decent 60' time with the 310, I think it was somewhere around your 60' times. With an extended swinger I know it had a 4.9 in it but I never got a chance to run one.

[Mosh]

If I recall correctly my Big Bore 308 cc Tri-z with a plus 4 swinger, was hitting 5.15 - 5.40 at 63-66 mph on dirt, with stock Ohtsu's on the rear. You are about where you should be I think. 1 upfront's air cooled 300R was running just a tick faster than mine with pro wedges.

[4x4van]

Very interesting 4x4... I never thought of trying a method like that. I'll give it a try sometime. :beer
Out at Glamis, if there is a few bikes lined up for a hill race, and a final rider comes up to join, and they take off just as the new rider gets there (but before he actually "stops") and he dumps his clutch at the same time as the others, that new rider will immediately get 2-3 bike lengths on the rest of the pack because he is starting from a roll (even a slow roll) instead of from a dead stop. It's a huge advantage, because the most time consuming part of any drag race is getting moving from a dead stop.

There was a guy in our camp, that could immediately get that kind of a lead as soon as we all dumped the clutch, even though he WAS stopped with the rest of us. We couldn't figure it out, till we actually watched him. While we were all clambered over the front end getting ready to start, he was back as far as his arms would allow. Then he would throw his body forward and dump the clutch as his "weight" hit the front. Even if he actually dumped his clutch a split second AFTER us, he would immediately pull out ahead by 1-2 bike lengths.

Since then, I have always started that way, as it "replicates" a "rolling start", therefore giving you a distinct advantage. Try it; it takes some practice to get it down, but once you do...no one will touch you on the starts!

[EK-Racing]

Thanks for the feedback guys. I just purchased and installed a phase 5 pipe, bike runs a lot stronger on top. This pipe seems to match the porting a little better than the stocker. Also picked up a 38mm PWK Keihin, need to clean it up and throw it on. The only carb boot I have handy that will fit the cylinder is from an 89' YZ250WR. It is angled though so I need to figure out a new filter setup. Hopefully with the Bigger carb and Pipe I can get this bike somewhere in the 5s.