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Stoffregen Motorsports

Member Since 26 Aug 2010
Offline Last Active Yesterday, 07:57 PM

#1511652 Clutch Hose Line unfreeze hack

Posted by Stoffregen Motorsports on Yesterday, 07:59 PM

Wow! Never had that problem before. I usually just burn through the penetrating oil with the blue part of the flame.

#1511411 620 Land Speed Record

Posted by Stoffregen Motorsports on 19 August 2017 - 07:47 PM

You could get a Winters quick change axle. They make a lightweight axle that can handle up to 300 hp. Not exactly cheap though.

I would be wary of a Dana 44 or 12 bolt, as gear ratio changes will be much more difficult. You could preset a few different r&p sets, but they're still a pain to swap in a hurry.

#1511046 Who can identify this front suspension??

Posted by Stoffregen Motorsports on 18 August 2017 - 12:16 PM

I wonder if someone simply swapped over all the balljoint suspension. The control arms, spindles, rotors, calipers, etc. I've never done it, so I don't even know if it's possible, but this truck definitely has the later suspension, the older style steering box and column, and the vented rotors (which I thought were only 720).

#1510964 Who can identify this front suspension??

Posted by Stoffregen Motorsports on 18 August 2017 - 09:05 AM

 sand paper.... and a fleshlight.


#1510947 Who can identify this front suspension??

Posted by Stoffregen Motorsports on 18 August 2017 - 08:27 AM

It's got balljoints and I think I see the steering box mounted inside the frame which would indicate 1978 or 1979 620 (720 had them mounted on the outside of the frame).


I wonder if it's had the entire frame swapped. Are you sure it's a '73? Have you cross-checked the VIN on the body against the VIN on the frame?


Note - if the VIN's don't match, NEVER bring that up in the presence of a DMV employee, or police officer.

#1510921 Wire a Frontier KA into a 720?

Posted by Stoffregen Motorsports on 18 August 2017 - 07:09 AM

It's so easy to do at home. There's only a handful of wires that you need to get it to run. It's too bad that such a simple problem is causing you to dump the whole project.


And "only 40 hp"...? That's a 40% increase over what you have.

#1510763 620 Land Speed Record

Posted by Stoffregen Motorsports on 17 August 2017 - 03:16 PM

Just remembered something...

Really rough track surfaces can cause enough vibration to keep the floats/inlet needles from working properly.

Had that happen on a super kart (back then called FKE-3) with the stock float style carb that I built for a buddy.

Went to a large Tillotson HR carb, and the problem went away, plus had adjustable jets :)

He ended up winning the 93-ish SWRA champion ship with that set-up.


Was looking at using 4 of their big HD (44mm) carbs on mine, but was taking forever to find 4 matched carbs unless I was willing to pay through the nose for NOS ones.


You being from the land of 10,000 mosquitos, there has got to be some vintage snowmobile shops around (for next year). 

Walbro also made a carb in that size called the WD.

Side drafts have been used for years in offroad racing. I wonder how they handle it? They probably run the float levels a bit higher and maybe even have extended float vents.


Softer carb mounts (isolators) would definitely help.

#1510722 KA Swap Header options

Posted by Stoffregen Motorsports on 17 August 2017 - 11:58 AM

Why do I care what other people think? I like seeing cool parts on my own cars and trucks.

#1510650 620 Land Speed Record

Posted by Stoffregen Motorsports on 17 August 2017 - 08:47 AM

I hate those 5/8ths upper control arm bolts, they were always working loose in my work truck and then breaking, it sucked when they broke as the front of the truck dropped into the pavement.

In the end the threads got stripped out in them holes(driver side), and I had to buy longer bolts that threaded all the way thru the back and stuck out by the shock, I then put big washers on the bolts and then threaded a lock nut on them and tightened them up till I could not tighten them anymore, it collapses that piece of metal on the shock side of the shock tower, never had them break or work loose since, I also used a much harder rated bolt.

I had them 5/8ths bolts break several times(5-6 times?), sometimes only one of them, sometimes both of them, they always broke when I touched the brakes.

I always tell everyone that is switching over to disc brakes on the early trucks to drill them holes out and tap them for the bolts used in the disc brake 620/720 trucks.

Are they 5/8" thread or 5/8" hex?


A Gr 8 5/8 fine thread bolt can take about 180# of torque, while the 7/16 fine thread bolt can take only about 60#.

#1510648 Steering box brace - any good?

Posted by Stoffregen Motorsports on 17 August 2017 - 08:35 AM

Yes, the 510 can benefit hugely from rear geometry mods. Flatter control arm angles are one of those mods. And yes, a stiff rear bar too. But be careful that the rear bar isn't out of whack with the stiffness of the front bar. Too stiff a rear bar can bring the back end around in a second, especially under deceleration. Also, solid mounting the rear crossmember to the body (without those rubber bushings) makes for a more controlled setup. Less crossmember movement equals less toe change,.


There's been a lot of hypothesizing about front steer vs rear steer on the front end. Some say that the front steer is more conducive to high speed. I never had a problem with the stock steering box setup, but one way I controlled the sloppy steering (you're going to laugh), I ran a large diameter Momo steering wheel. With a Nascar style seating position (arms not so stretched out) and a large wheel, I could saw at the wheel like they do in Nascar and not wear out my arms. It worked for me!

#1510464 Wire a Frontier KA into a 720?

Posted by Stoffregen Motorsports on 16 August 2017 - 11:35 AM

I have a shop in South Carolina do my Toyota wiring harnesses. A complete plug and play harness from them is only about $600. They go by two names - http://www.phoenix-tuning.com/and http://www.tweakdper...com/index2.html


I'm pretty sure they do anything.

#1510446 620 Land Speed Record

Posted by Stoffregen Motorsports on 16 August 2017 - 09:40 AM



According to everyone who has been here for years, this is the worst salt they have ever seen.  Most of the big teams left Sunday or Monday. 


Error on my part:  the distributor needs to be on a separate switch from the main power, as the driver uses the Cool Shirt for quite a while, feeding power to the ignition for a along time with the truck not running. 

Bummer. I'm sure it is still a valuable experience. A bad day racing is still better than a good day at work.


I've run into that problem with electric fans. Now any motor gets put on a relay.

#1510445 Steering box brace - any good?

Posted by Stoffregen Motorsports on 16 August 2017 - 09:35 AM

Just for the sake of argument, I'll point out that the 510 body shell is comprised of two basic sections, or boxes. The main body area is one huge six sided box. The front area, or engine bay is a box with only four sides. When a roll cage is installed, the already stiff main cabin becomes very rigid and it becomes even more necessary to use a strut tower brace because the stress points have been concentrated in two locations of the flexy four sided box at the front.


This is all perfect world scenario thinking. I'm not standing up and yelling that everyone needs to modify their chassis for strength or tuning.


It's also amazing how the technology has advanced the structural integrity of cars these days. A modern car (anything built after the mid 80's) is so much more capable than anything built before that. As a few have pointed out here, a stock modern sedan will outperform an old sports car. I remember a trip my brother and I took once in his MGB. It was a 2500 mile trip that ended on a rainy night through some back roads of northern Wisconsin. The road nearly killed us. The next day we took my grandmother's new 1997 Lexus GS300 for a spin. We were able to do nearly twice the speed in the same wet conditions on the same twisty road that we arrived in the night before. A modern sedan which weighed at least two times as much kicked the MGB's ass.


The old box of a 510 is no different. It has it's strong points, but they have to be taken in context of the era in which it was built. And with what we know now, we can definitely improve upon it.


BTW - regarding paradime's comment on the 510's IRS, we used to run 800 to 1000 lb springs in the rear just to keep roll steer to a minimum. With a lot of HP, that rear steer can be fun, but dangerous as hell.

#1510149 Electric Fan Switch

Posted by Stoffregen Motorsports on 15 August 2017 - 07:09 AM

Trying to clean up the engine bay, eh? Using those adapters is not going to help with the clean-up effort.


There are a few other options out there.


Here's a switch from Pegasus Racing - https://www.pegasusa...AiABEgKZp_D_BwE


There are a slew of them available at Summit Racing - https://www.summitra...Order=Ascending

#1509621 Steering box brace - any good?

Posted by Stoffregen Motorsports on 12 August 2017 - 09:23 AM

The bummer is, we cut up and threw the car away. With my skills now, I could easily have fixed the tub to fight another day.


This is about the only picture I have of that car.