VooDoo Max

[Bob Vehring]

Chuck, hope you don't mind but I've already draged this story far off VMax at times. here some history on the AC/Rupp I want to bring back to life

This is the 81 SRV I bought as a wreck back in the 80's, that kid is now 34



This is the 76 Eltigre with a 440 Rupp engine along with Wendy 79 SKi Doo Thees slightly pre date the SRV



The AC/Rupp became more of a race sled and the SRV became my trail rider





When the AC went to racing only, I covered all the vents in the st hood, took a mold off it and made lightweigt hood without the vents
Here it is after the seat and every thing for trail was removed



Last build on that sled was to cut off the entire ft end and make a chrome molly tube ft end. The small yellow springs above the skis cam from a BB chevy race engine and gave the required 2 in of travel



It also got a Prowler hood and Nitrous this sled lasted 5 races and flipped and I hope to put the Indy ft end and long track on



When I die, will someone print all this out and nail it to my tombstone, well if I get one

[Bob Vehring]

Sorry not sure why but the right side of many of my pix get chopped off, not sure what I'm doing wrong

[Vmax540]

5th race out it exploded a track and flipped very hard, sled went through at 128, Wendy followed at 108 on her ass. Stripped it down and has been in the basement since mid 80's
going to weld it up and probably put a 617 Rotax I have sitting around in it, maybe a 144 track and skid to get off trail a little

wow.... does she still ride things you put together ?
B.T.W. Love the old pictures !

[Bob Vehring]

She did for about 8 years after that. The crash happened and ended her racing for that year. I started looking for a replacement sled to build a new open out of. What I found was the '81 ElTrigre 6000 I still have today, picked it up for $300 with the plan of stripping it down and using the bare chassis as a starting point. It sat around for awhile, and the more I looked at it, the more I thought it was too nice to chop up, good plan because its probably worth more today
The '79 SKI DOO 5500 Blizzard, pictured above had been Wendys trail sled, it had a nasty problem with loosing spark at the worst possible times so she took the AC for riding and I chopped up the SKI DOO. It became, well atleast the tunnel became the open mod I still have today. Wendy raced that untill the kids begone doing well in Karting and their winter races down south pretty much stopped sled racing for about 10 years
Heres the 81 A/C



This is the mod made from the SkiDoo



This is Wendy back in those days

[Vmax540]

Me likes...... btw are you going to post any sleds....

[Bob Vehring]

Well believe it or not, 9 pages here, 9000 views and the engine has been assembled for the last time and made the trip home to my house. Still work to do, have to make some ex. flanges, can't open the stockers enough to match the port. Then the big project, getting the chassis dug out and everything installed, its pretty buried in a shed
I wanted to dyno it before putting it in, but Perrys is down and far to big for our dyno Hoping to make first ride up at Eagle River during Derby week.

[Bob Vehring]

I guess I should be somewhat embarassed that it took this long but I pulled the rope on the Vmax and all 618 cc's fired right up. Still have to figure out clutching, using a wide belt Pol, Pri. and have to either do some work on the OEM sec, or the people at Micro Belmont are willing to make me one of their shafts that adapts a Cat sec. to the yamaha. Would like to go that route but now am in a hurry to get it running. Have to work on some elec odds and end yet but hopefully out soon

[Vmax540]

Bob, Way to go, we knew you had it all the time. Now, I can not wait to see some results !

[Bob Vehring]

Well I thought I had my elec problem figured out, was a 3 wire plug just sitting down below radiator.
I dis conect the Bl/W and it runs fine, tells me its in chassis wiring. Just guess that the stray wire was for TORS, but I guess I don't have that, So looking it up on the wiring dia, it should be the brake light wiring. Odd thing is, brake light works fine.

[Bob Vehring]

Sorry I never updated this, Got jetting and clutching close, a little trail riding in, pulls good but spins the track most of the time, will have to find a bigger lug track, not sure how big I can get in there and still use picks.
Close enough to start new projects, have both a 87 SRV and 80 something SS440 sleds. Have 4 engine choices, Fresh stock 440, rebuilt 540 SRV, 600 cc Race SRV and update ported VM 540
Which ever gets the 600 SRV, will be a lake race toy, Thinking about the slightly modified 540 in the SS

[Vmax540]

I always hoped to find a clean SS440, I have seen some well done and would think a SRV would be awesome in one.

[Bob Vehring]

Chuck I got in spring the SS and a '86 SRV, same guy I got the Enticer 250 from several years ago. All 3 have sat outside for probably a decade or more. The SS is alittle nicer then the SRV not much serious rust, put seats are bad, hoods cracked which are both easy for me to fix. Both also need complete paint but I can do that
Both need most trim, windshields and trim, the SRV needs bumper covers and the plastic that covers the top side of the struts. Let me know what you got in your SRV pile

[Bob Vehring]

Way back when I first got this thing I went through 2 different OEM temp gauges, then tried a known working Autometer gauge. None work and alot of people seemed to have that problem. Once I pulled the engine out and looked at it, looks to me like there is no reason any real water flow is going to travel through that little factory hose which goes from the bottom to the top.
Last week I finally got to installing a fitting in the main water tube. $38 for the blue anodized AN fittings, right now mounted in the upper hose, that may change but everthing seems to be working fine and matches reading from a temp gun. Probably will go back to the OEM gauge when I get a chance.

[Vmax540]

Good Job, Bob (that rhymes) Where did you get the blue anodized AN fittings (I'll add to the read list) and what is the LCD monitor do... You tube videos ?

[Bob Vehring]

Local stock car supply place here. Just a T for a 1 in line and the housing is made for auto temp gauges. 38 bucks total cost

The other gauge is a MyChron 3 Gold. Standard stuff for kart racing where we now all use MyChron 4's, but I moved our older ones onto my sleds
From the top to the bottom, the lights across the top show RPM and are programmable. I set the outside one on each side to come on just below clutch engagement. Their bright LED's so even in daylight, when I see a green light, its just about to move. Nice at a race track when watching a flagman or light.From their they just go up, 1000 rpm at a time.
The 4 lights on either side are set up to monitor EGT. Again I use the warning lights so I don't have to stare at the gauge but all functions are displayed in the center both as digital numbers or a bar graph.
I set the lower light on each side to turn OFF, at 1000 deg. The upper light is set to turn ON at 1250
This way if riding and I see no lights on, EGT for each side is between 1000 and 1250 deg. Seeing a light flicker tells me which side and weather I'm low or high on temp.
that's all I look for while riding, and I only have to see the LED light, not really read or watch the readouts.
When doing set up or testing there are afew things more it does. It has a speed pick up, which I mount to read off the sec shaft. Knowing gear ratio, driver and track size, it can give you real MPH altho that's not what I'm looking for.. It will store all you testing, then it is downloaded to a computer. The program allows you to look at any data, any way you wish. I overlay the speed channel on top of the RPM channel. This produces a graph just like the ones in Aaens clutch book. You see absolutely everything that happen in both clutches instantly and for every run you made. Make some changes and you can overlay the tests over the old one. Change a helix and you see exactly where it mover things.
Same deal with EGT, change jets, overlay the sessions and you see what changed. We use a larger version of this on Regans race sleds. He gets back to the trailer and I have all this up on the screen before he has his gear off.
I feel bad when I see what people are paying for Digitron or Koso gauges when this stuff does so much more, but not may people in the sled world know about it. MyChron/AIM took over the kart world in late 90's and today is involved in every hi end type of racing. The karting, MyChron 4 gauges start at $359.new, but used ones are everywhere on Ebay or Karting sites just like the ones I have here for $150-$250 depending on number of channels.