1976 Nitro Grass Drag Set Ups

[Ruppsforever]

Sending cylinder out tomorrow to get replated. Will be back together soon !! Porting another set of cylinders so if the nikasil over the steel sleeve gets tore off again I have extra cylinders. I know I can make improvements on the porting over what I ran for years. LOL !! Thanks for the compliments !!

[midniterupper]

Fantastic Josh! We are all excited and know you have the talent and skills to make Darth the World's fastest Rupp! Can't wait to see what you create with your new porting concepts. Good luck with that and keep us posted on your progress!
We're sure glad we don't have to race against you!

[Ruppsforever]

Thanks Paul !! Yeah porting won't be much different but will be a lot cleaner. Should be worth a couple more HP. I'm glad I don't have to race against me either !! I already have a few more ideas for next winter to make my clutching better. LOL !! Making some more helixes soon !!

[midniterupper]

Boy! How time can fly by, here is the end of the Winter '21 riding and race season already! 2022 certainly has gotten off to a year of uncertainty hasn't it? Sure hope things can come to a peaceful and calming ending with Ukraine.

Well here on the home front things are progressing nicely for our upcoming Grass Drag race season. A lot has to do with all the work from last year, helps to have a few seasons behind us now in regards to having extra tuning parts on hand. But before we get too far into this year's progress, I need to give credit to some good folks around here that has certainly helped our efforts.

First of all, I feel really fortunate and blessed to have the opportunity to make so many great friends here through our Rupp Message Board. There is a vast wealth of caring and knowledgeable people on this site who are willing to help any fellow Rupp enthusiast with their project sleds. Hats off to you guys and a big "Thank You!" for sharing and helping so many of us.

This "Thank you" goes out to Clint, Josh and Bill for contributing your time and talents to help me out with my sled. You guys have done a lot of work behind the scenes for me in so many ways and it definitely shows. Clint is always so encouraging and is a walking shop manual, loaded with any spec you may ever need!
Josh is one of the best "Motor Man" you'll ever be fortunate to find in our country. His "Darth Vader" is a tribute to his skills and a true threat to any racer that is willing to test their skills to beat him. Not gonna happen in this universe!
Then of course we have Bill to be grateful for also. Bill not only builds spectacular race sleds and motors, he has an awesome award winning body shop and inventory of Rupp parts that can rebuild any of our project sleds! He is an encyclopedia of Rupp history and knowledge, always willing to help out any of us at any time.
Kevin is another giant in our community. His shop is probably one of the most well equipped engine rebuilding facilities in our region. He has a specialty machine for each and every process involved in maintaining, rebuilding or improving an internal combustion engine. He is a true perfectionist in his field, nothing leaves his shop without him ensuring it's at it's best!

We all owe these Rupp Ambassadors our deepest appreciation and respect, Send them a line when you get a chance, we're all lucky to have them on our team! I know there are many more too that have helped out our Red passion, so Thanks to all of you too!

Okay, now for some updates since our last chat. We didn't race in any formal Ice races but we sure had some fun with the sled this past winter. Every time we took the Nitro out, it ran great. We played raced other Vintage sleds at some shows and vintage rides and had a ball! Nice to be able to ride and play with other nicely restored vintage iron, some sleds look better than the showroom floors from way back then. Powder coating and detailing were incredible, lot's of pride in their ride!

We attended some nice events in our state, some were simple gatherings for the sleds to be seen by the local communities. Others were shows that also held a short ride which was really nice. We didn't use our sled for the rides but we did the shows and even played "hill climber" on some ski hills that were shut down at the end of the season. That was fun! Our Nitro was the only Vintage sled to make it straight up the mountain to the very top, people loved it! We even won 2nd place for Best of Show at one event this year, and that was with our old hood! People love seeing the old Rupps still kicking butt!

Since the shows I've finally had a chance to fit Bill's hood to my sled. It took a little work to get the mounting hardware painted and installed correctly to make it mate properly and I also purchased the inner scoop from Bill that goes along with the new hood. I'm glad I bought it because it really compliments to Sno-Pro look. It really looks awesome! I wish I could get a picture of the sled on this forum but my file size is too large.

So for this year's racing and testing strategy, we have a lot to review. I want to develop a precise and detailed plan to organize the new clutches, springs and helixes that we have on hand now. I bought some wire tags that will be used to identify secondary helixes for charting along with their results. We have a ton of secondary springs from Josh to try out also, again tagging and documenting the rates and effective test results.

Through last year's efforts, we can now do comparison testing of the Arctic Cat drive system verses the Polaris drive systems. We have 2 complete sets of each manufacturer's clutches to try out for this year's test sessions. I can't wait to see the results.
I even found a set of the Polaris 10MR weights over the winter at a show. I've been wanting to try those out for 2 years now but could never locate any. This year I got the set for free, can't beat that!

I did manage to finally replace my track drivers. They were very worn, to the point of trying to climb the internal drive lugs on the track at high speeds. You could see some evidence on the lugs themselves, little chunks were torn off. So I ended up using the Anti-Ratchet drivers from Wahl Brothers. They look awesome and very effective too. I bored them out leaving a .003" press fit to the axle shaft. Worked out great! I was going to make a new rear axle incorporating only 3 rear idlers as an attempt to reduce my rotating mass. After studying the 4 wheel set up, I decided to just keep what I was using because the wheels spin so easily.

I will order new chisel studs for this year to help with the traction, can't hurt. I also need to organize and review our testing notes for the last 3 seasons now. There is always good ideas hiding in our past results.

Well, that's about it for now. I will post more as I get more done and certainly when we begin our testing. Also still want to get some time at Extreme Dyno as opportunity prevails. Keep you posted on that too of course.

Take care to all, and Thanks again for reading.
Stay safe!
-Paul

[Ruppsforever]

Can't wait for you to get out testing again. Let me know if I can help !!

[midniterupper]

Okay, we have some good news for our Nitro. As you all know by reading this thread, I have been struggling with my exhaust temps to be in the normal heat range of around 1150 - 1250 degrees. Especially the mag side which was running consistently 400 degrees colder that the pto side, leaving unburned oil and fuel spitting out the pipe, surely losing horsepower.

The problem was due to me installing the Thunder Products U.F.O. discs under the carb slides. I have used these ufo's before on other sleds and they always improved the throttle response and general performance. I installed them on the Nitro almost two years ago. However, with this motor, no such luck. I purchased 2 new slides last year with a 1.5 cut away from Wahl Brothers but never had the chance to install them and play with my jetting a little more to dial them in.

Well, at this point the sled is nearing completion for this year so I have a little more time to do some of the "back burner" ideas. I removed the slides with the ufo's and installed the new ones. Fired up the motor with the sled on the stand and immediately both cylinders warmed up to 1000 degrees at 6500 rpm! Talk about excitement in the shop, boy it was great. The mag pipe got hot enough to burn out all the old drool and no longer spits and smokes. The engine exhaust temps are actually responding to jetting changes now, finally!

So now, for this year I added 1 tooth to my upper sprocket, replaced the 4 driver system with a 2 driver anti-ratchet system, and now we have our exhaust temps in the 1250 degree range so we are producing more power for sure. Should be an improved combination to help break into the low 70's. Can't hardly wait, should be a real threat to the Improvers!

That's it for now, the lesson is to never leave any stone unturned! You never know where the performance is hiding!
Keep you posted!

-Paul

[Ruppsforever]

Yeah those pipe temps should really help !! Were you off a little bit when you ground the throttle valve ?? I for one am not happy when my pipe temps are 15 degrees difference !! I at one time made a set of those UFO's but then decided it wasn't worth the hassle. My jetting was spot on already and didn't want to start over. Mod motors are very finicky in the first place LOL !!

[midniterupper]

Well, well, How time can fly by! Here it is August already. That means Grass Drag Race Season is here! We've been pretty much ready since spring time, although we haven't been testing as much as we should. The Nitro is running great, everything is aligned and ready to begin testing. Our testing this past spring was encouraging, topping out faster with each pass settling in at 65-67 mph pretty consistently and easily. So, with a little dedicated time and effort, I believe 69 mph should become our new basis for improvements.

We will have to wait on testing for the next couple of weeks as we have 2 Vintage shows we are entering. The first is for really nice trophies, the second is pretty much just a 5 day show of Vintage engines. It's a Old Engine Show but they want any snowmobiles from 1976 and earlier so we're there to represent the Rupp line of sleds, I wish I had more. We were there last year and we met so many cool Rupp enthusiasts, lots of stories! Can't wait!

This year we have our new hood from Bill on the sled, I know it will really draw the attention this year at both shows. Maybe even have a shot at winning the "Race Sled" series. Very tough competition with the twin trackers right from the factory but those sleds don't even have fuel in them to run. I plan on stinking them out by burning a little fresh race fuel while warming up my track in the display area! Those pretty models are just Glamour Girls, ours still spits dirt!

Okay, that's all for now. Once we get back from the shows and we begin our testing I'll update more. There's so much to do yet and so much to try out, it's really exciting! We had to re-schedule our dyno time for later this fall, which is good for giving us time to develop more combinations. Maybe this is our year to break the 70 mph barrier for the Stockers!

Good luck to all, stay safe, think Red and stay cool!

-Paul

[Ruppsforever]

Good luck at the shows !! Have fun !!

[midniterupper]

Well, We are back from the shows. Whew! Lotsa work doing these "fun" things but very well worth it all. At the show in Kaleva we met so many neat people, a lot of true Rupp enthusiasts attended. Only one '72 Magnum to represent the Red line along with our Nitro but there were some really awesome sleds there anyway. Over 60 sleds registered, ranging from the excellently restored rear engine snowmobiles from the Antique Snowmobile Museum in Naubinway, to the factory racers from Quebec. (Guess who won right?)
Anyway, the best part of the show is making new friends who also race (or has in their past) and are willing to share some fantastic stories of legendary racers of the past. Then to see the excitement on their faces when you ask them to sit on the sled for a picture! Priceless! Like kids on Christmas.

Now the Buckley Old Engine show was a bit different. There we displayed the sleds along a hillside to make them appear to be racing, it turned out great. Then it rained, then it got hot and dusty, then more rain, so you get the picture. I felt bad getting Bill's work so dirty but it still shined and looks awesome. Today I pulled that hood off and put on the original for the drag season. Also pulled the skis too in order to preserve the powder coat finish for the shows. Then swapped out the soft show primary spring too, installed the 6200 rpm engagement spring. Now we are ready for testing!

So today we fooled around with secondary helixes and spring preloads. On our first test we once again used the unidentified black anodized cat helix that we played with last year. It gave some great performances out of the hole last season but would fall flat on it's face about half track on. Still topped out around 67-69 mph even when it fell flat so it certainly draws some interest. However today it's first run only ran 54 mph with the preload at 18 pounds. For second pass I increased the preload to the third hole position at 26 pounds (never gone that high for drags) using the same red spring and it ran 64 mph. 10 mile per hour gain, sure wish we could find that formula for everything! I guess you never know until you prove it out for yourself sometimes. The research shall continue....
Funny thing about those two passes. Using that helix, the sled launched like no other! Great holeshots and wheelies, excellent acceleration until it shifts into something weird and causes my sled to "surge". Usually about half track with 18 pounds preload. With the preload at 26 pounds, the surge did not occur until 3/4 track. Maybe try throwing in a shim to see if we can keep it from fully shifting out. Something to try this week hopefully, we race on Saturday so time is getting close.

I did meet a gentleman today that said he has a fixture for measure the angles on helixes. He is supposed to come by again with it so I can make one similar to it, sure will come in handy.

Our other tests today were fooling around with helix angles and spring combinations. Some caused over rev (8500+) and some caused under rev (7800) with varying speeds of course. Exhaust temps were also affected by different helix/spring combinations which surprised me too. So, all in all it was a good day for testing and we learned lots. Best of all, I was able to get more seat time in.

Hopefully we will get another day in of testing before the races. I will bring a bunch of clutches to the track if necessary, don't want to get caught going slow!

Keep you posted,
-Paul

[upmagnum]

I attended the Kaleva show many times in the past with my Rupps but haven't been there since I kinda left the hobby. You might say I started that show but that's another story. Good times.

[midniterupper]

Hey, thanks for sharing about the show. I look forward to hearing more, I'll bet it's very interesting and maybe something I can learn from and apply to the Buckley Antique and Vintage sled show. I would love for it to be a success too for years to come, there are so many good machines out there waiting to be appreciated!

Well, the races this past weekend were a lot of fun. We are beginning our third season with this sled and our race family is growing with anticipation and support. It's really awesome to have people approach you and say they have been following us to various events for the past couple of years and love to see the sled out there running so strong. We may not always win but we are always contenders, people love seeing the old Nitro stir up the hornet's nest!

The competition was good, ranging from the usual Yammie's to some new comers on Polaris white bombers. Practice/testing went well they all appeared loud and fast so it looked promising. The bummer was that the event organizers did not include a Stock vintage class so some of the stockers did not even race because they felt unfair racing against the improvers and open mod sleds. But you guys know me by now, I'll enter any vintage class (racing slut!) just to take the sled down the track so I was up against 1 Yam stocker and 4 improvers who also ran open mod. However, after practice and eliminations, one by one they were dropping like flies and either quit while going down the track or would not restart on the line. Guess you still have to cross the finish line in order to have a win right?

So, we took second in Improved and first in Open mod which really was only because our sled was still running by the end of the day to cross the line. It was a great weekend with great friends who made up our team and a lot of Rupp fans that enjoyed themselves as well so I would call that a success. Our next race is on September 24th so we have some time for more testing which we desperately need to do.

The sled is running rather slow for some reason, topping out at only 63 average which is not going to win many races. We tested at the track switching out 2 Arctic secondaries and settling in using a Polaris secondary to race with which is just the opposite from last year's performance. No biggie, we'll figure out the magic combination to make her consistent (and faster!) Just glad to be out there racing and hanging with the fast boys.

Well, I better move along here. It's supposed to rain today so maybe I can evaluate the sled and see what we can try next, pretty fun and exciting stuff!

Take care now and go have some fun!
-Paul

[midniterupper]

Well, We had another great weekend of Grass Racing here in Michigan over this past weekend. We attended a race we've never been at before, the event being held in Wayland - a nice smaller farm community.

There were 54 sled registered to race, all machines had to be model year 2000 and older, nothing bigger than a 680cc engine so it was really a neat venue for the Vintage racers. They had you run a couple of passes to get your time and speed established then they set up all brackets accordingly. It is a fair way to race, if you beat your own time by more than .4 tenths you became DQ'd.

Our class was from 7.5 to 7.9 seconds and we had 8 sleds to compete against, ranging from yammie phazers and gpx's to even an old Suzuki Fury. All were improved or modded out in one way or another so they were all loud and fast so we had some good competition to play with.

We won every one of our heats, some were close, some not so much but with every run we had a blast! Great sportsmanship too. We made it to the final, had the holeshot and the entire race ran within a half of a sled. We stayed ahead but somehow the opposing finish light got triggered and the race technically went to the opposing team. When we crossed the line, the other driver even said we won but he was awarded the win. That's racing! Great competition against some great old iron! What a ball!

The old Nitro was polished up and ran very well, very consistent and fast. We had so many people come by our pit area to compliment the sled. I must say that I too am impressed with it's reliability and performance, it's been such a nice sled to work with over all these years. Sometimes it's frustrating but it's always rewarding too. It really helps to race against some other nice Vintage machines to compare it's performance. It's also nice to have people recognize your efforts to make the machine a winner. Rupps Rule!

Next weekend we race at Twisting Trails hopefully. We'll see how the sled runs against those boys next, not much time to tune so we'll see what we can do.

Take care now, we'll keep you posted. Wish we could send videos through this site, we have some fantastic footage!
Thanks again for reading and your support!
-Paul

[Ruppsforever]

Sounds like she is running well !! I hate that when they give the win to someone else. That is just wrong. Had the same thing happen last winter when I blew up. Had a whole sled length lead at the line they gave the win to the Ski Doo. He even said I won. Good luck with your next race !!

[midniterupper]

Okay, finally have some time to update on the Nitro. Last weekend at the races were fun and fast. There were many more Vintage sleds participating than usual, probably the good weather bringing people out to play. More than 20 Vintage sleds arrived!

Anyway, the old Nitro held it's own by earning 2nd place in Vintage Stock, 2nd in Improved but only 5th place in Open Mod (out of 8 sleds) so not terribly bad but we certainly usually do better. However, the competition was very fast which made it a blast to go play. As always, it was great to see the old iron out there running and everyone having fun. Adding two more trophies to the shelf this past weekend doesn't hurt either, 17 of them up there now and that doesn't include the payback wins. Not bad for a sled 47 years young! Gotta love those Rupps!

That was another great aspect of this past week's races. We had so many people swing by to pay tribute to the sled, I am always amazed at how popular the old Red Sleds still attract people of all ages. It happens every time we race the sled, everyone is so impressed with the performance of this sled - even when it's not running it's best. Sure makes you feel good when they tell you that they love seeing it run down the track, we may even have a few groupies following us!

So now with this all being said, the sled is not achieving the top speeds that we should be getting. I believe I have a friction issue somewhere in the drive train. Let me explain why...

Right now the motor is running better than ever. We finally are running both cylinder exhaust temps at 1150-1230 degrees. Plugs and piston wash patterns look pretty near perfect. Engine RPM response is the best it's ever been, going from either idle speed of 2000 or at 5500 rpm (where I usually keep it before launch), it instantly pegs out at 8300 and I mean like now! Truly awesome!
Also, we are finally able to dial in our max RPM and we have been staying at 8100 or 8300 depending on our helix angles and secondary preload settings. The primary spring rate seems to hold the rpm's nice and steady, staying within around a 150 rpm variance. I think we can get that even better but good enough for now.

With everything working so well with the engine, I must have something going on with the chassis or drivetrain because we have dropped our top speed from 65-67 mph and on occasion even 69 mph. And those top speeds were accomplished when the motor had one cylinder burning at 800 degrees and RPM's staying below 7900, I know we must be able to do better.

So what the sled is doing is blasting out of the hole, awesome holeshots and wheelies. Always ahead of the other sleds for the first 60 feet or so, then they start coming on strong. The Nitro seems to lose acceleration just past half track. It doesn't slow down it just seems to lose the rush of acceleration and happily crosses the finish line, not blowing across the finish line.

This past winter I replaced my worn out internal lug drive drivers with the new anti-ratchet style drivers. I am wondering if maybe I am running into additional friction from the male sprocket teeth rubbing on the track clips causing an abnormal wear pattern? I know that running in dry dirt, wet mud and clay doesn't help the longevity of these drive sprockets either but I do see wear on the teeth that may contribute to the problem. I may try to pull the axle back off and throw it on the lathe and try reducing the height of those teeth, maybe eliminating the additional contact equaling less overall friction.

We'll see, may have to retrace our steps and start from square one again to see what is the cause. Verify each bearing, perform alignments and see where the problem lies. A lengthy process but thorough, should reveal something!

One thing I did want to share was installing a new jet needle in the carbs. I originally had a 6DH4 needle when I bought the sled. Then I installed a set of 6DH7 needles and the performance improved slightly so they were worth using. Then last month I re-read an article by Olav and he mentioned that reed valve engines can benefit by installing a straight taper needle such as a 6D4 series. Apparently the double taper needles are more intended for piston port engines. So I ordered and installed them, played with the settings a little bit but let me tell you, they made a big difference in my throttle response! No more slight bog at the line and the motor just sings at 5500-6000 rpm before my clutches engage at 6200 rpm. Sounds sweet and runs even better! You guys just may want to see what you have in yours, Might help.

Well, that's all for now. Maybe you guys will have some ideas on what to look for regarding the sled slowing down. Sure looks and sounds fast, in fact, sounds better than ever, but we lost over 6 mph somewhere. Perseverance shall prevail!

Until the next time, Stay Red! Thanks for your help,
-Paul

[Ruppsforever]

I would have to agree with you on those anti ratchet sprockets. If you are seeing signs of wear then yes they are probably slowing you down. I've never ran those sprockets before so I have no experience with them but sounds like you found the problem. That sucks.....

[midniterupper]

Well, my my. How time flies by this year. Hope you're all doing well, everything in Michigan is going great over here. Today was an exceptional day in fact: In testing our Nitro reached 71 MPH! First time ever!

As I mentioned in my last post, we had some issues to figure out that was causing our Nitro to slow down a bit. I think we got it figured out, here's what I did.

I stripped the chassis down bare expect for the motor, I left that in place but found a weak rear motor mount. Under the load of a big prybar, the engine would flex about 1" possibly causing the clutches to become mis-aligned under acceleration. I machined a new set of rear mounts out of aluminum and that seems to reduce the flex substantially.

I also had access to the Jackshaft and brake disc assembly so I was able to verify no additional friction loss occurred there, all bearings still work great. Always helpful to verify though, continue the process of elimination.

With the driveshaft out, I put it on the lathe and turned down .200" off the O.D. and then radiused the external drive lugs to ensure no interference occurred there. Smoothed and blended everything nicely, no more interference there. With the track removed, I reinstalled the drive axle in position and mounted a dial indicator in the tunnel and measured the actual run out of the axle drive sprockets. Only .005" Total, not enough there to mess with!

While the rear suspension was out of the sled I was able to align all idler wheels to track evenly and smoothly. I also checked for interference between components in any position. Everything is now tracking straight and true.

Then I reinstalled everything, performed the track tension and alignment procedures, setting my track tension at about 1 1/2". At that setting, my track spins easily by hand. Very little resistance and the studs don't hit the tunnel area.
Now my track will easily rotate forward and backward without any noises, rubbing or jerky movements. Very nice! It's never been that smooth before.

Oh yeah, while watching a video in slow motion at one of our races, we noticed the front skis were crooked while in the air at the starting line. I propped up the front of the sled to get the skis off the ground and found almost 3" of slop! I machined up new pivot bushings and reduced the play to less than 1 inch. Maybe the excessive play was causing our skis to sort of "snow plow" while going down the track?

I also found a huge in line fuel filter while out shopping so I bought that and installed it. Not sure if that could've been a problem but it isn't for sure now! Fuel really flows!

In testing today, the improvements and work we did definitely paid off. The motor is running it's best, great exhaust temps and response. We do have a slight RPM fluctuation at mid track but then clears out so we need to address that issue but no real big deal there.

I now need to install hydraulic brakes on the sled, it just doesn't want to come to a stop in a short distance. Good winter time project.

I can't wait to resume testing next spring. Should really be able to dial in the sled good by then. Next year's competition is going to be surprised, they beat on us pretty badly this past season, I think we only earned one 1st place win. The previous years we beat on them pretty good, I think this coming year will really sting! Just when they think they got us.

Well, that's about it for now. Thanks again for your reading and interest, hope you all have a very Merry Christmas and a wonderful Racing New Year!
Take care,
-Paul

[Ruppsforever]

Real Nice !!! So you still have the anti ratchet drive sprockets on it ?? You radiused those and now no interference ?? Don't touch a thing on that bad boy !! When you get those hydraulic brakes on you might have to shim them away from the brake disk. I had to add several washers to get it further away from the brake disk because it likes to rub on the disk. Congratulations with your progress !!

[midniterupper]

Well, Hey there! Can you believe it's already testing season once again? (At least for us Sod Rippers!) It seems time is not going by any slower these days, but it must mean we're having fun right? Absolutely!

During my "off" season I attended some Ice Drags on our area. Holy Cow! These sleds are screaming nowadays, incredibly fast. The talent and money spent on these ice warriors seems to have no end. Every year they just keep getting faster, pretty exciting to watch their progress.

Also, with great guidance from Josh, (Thanks Josh!) I finally installed my juice brakes. The install was remarkably easy once you look at it and the parts are readily available through Wahl Brothers. A great investment especially considering the safety factor. Sometimes there is not much shut down room at local races so these are going to greatly help reduce the pucker factor. They really make a difference.

And, after looking the sled over during the winter, I realized the track studs were very worn out. So I removed them and installed new ones. I'm sure they'll really hook up but the downside is that I will have to run the track tighter in order to prevent the track slap causing the studs to hit the tunnel area. No problem doing that but it may cost some horsepower getting to the ground.

Along that topic, I was able to schedule some time with Extreme Dyno for the end of July, just in time before our first race in August! They have a track dyno that sits in the sled chassis verses an engine dyno but it will help to see the actual numbers. This is where the drivetrain efficiency will pay off. I'll post the numbers once we have them.

So today I was finally able to begin our testing. It has been so dry around here this spring/summer that our test track was nothing but silt. We got some good rain this past weekend and the track shaped up enough to make a couple passes. I haven't changed the tuning on the sled because it performed so well on our last testing session of last year when it hit 71 mph. But we did experience a miss around half track that needed to be addressed.

Our first pass did alright running at 66 mph but the track studs were slapping the tunnel so I let off. The engine did experience a miss consistent with last year's run. After reviewing some videos from last year, the miss did appear at some races toward the end of the season. So apparently the problem progressed.

For our second pass, after tightening up the track, I opened up the bowl adjuster screws about 1/8 of a turn each and left everything else alone. The miss was significantly reduced and we hit 69 mph with no track slap. Pretty encouraging, the miss must be a fuel issue so that's easy enough to address.

Once we get a little more rain we can do more testing but so far the sled is coming along nicely. I believe this year just may be our best yet, how exciting is that!

Keep you posted as progress proceeds 

Until then, keep seeing Red!
-Paul

[Ruppsforever]

Keep up the good work bud !! I've been working on my sleds nonstop since winter. I broke so much stuff it is almost unreal. Getting very expensive. My flywheel even cracked. In the process of lightening up another flywheel and trying to knock a little more weight of my sleds. I also need to get the dyno out of retirement to make sure my new cylinders are good enough to race or hopefull they are better that my old ones.