620 Land Speed Record

[frank88]

Any updates on this?

[distributorguy]

I'm just getting everything in place for Winter.  The truck is now back in the shop where it will reside until Spring.  Our first goal is to get a running motor into it, so we can iron out balance, steering, and of course get the roll cage and all safety gear 100% up to snuff.  A bit of driving on a frozen lake will be as close as you can find anywhere to simulate the traction conditions of salt, so that WILL happen - likely in Jan/Feb when conditions allow.  

Every potential driver who has sat in the truck wants more leg room, so that may become a priority.  No idea how, but we'll find at least another inch somewhere.  

And I have continued to port the cylinder head, but I'm flat-out sick of it and need a break for a while.  

 

In the end, it comes down t the weather turning crappy and cold so I have more free time to play in the shop.  We will be meeting Thursday nights starting next week to drink beer and pretend we are working on it.  Who knows - maybe something will get accomplished? :thumbup:   

[frank88]

Good luck! Suppose you could tilt the seat a little less but not ideal.

[wayno]

I have found to get more legroom, raise seat, or tilt it back.

[G-Duax]

Live with it.......

I've seen a lot of LSR cars that the driver was such an afterthought.

I mean crammed in with a shoe horn.

 

I forget, do they test to see if you can exit the car in a set amount of time ?

[distributorguy]

Yes, you have 30 seconds to stop the vehicle safely and exit safely.  I designed the cage around the driver and a safe exit, not comfort.  I'm 5'10" tall and I can easily exit in under 10 seconds.  The bar behind the seat is where the shoulder belts attach, and that's what's keeping the seat forward.  I'm thinking I'll install a smaller tube (legal for our class) and offset it tight to the sheetmetal.  That might be close to 2", so huge!  

 

We can't raise the seat, because helmet to cage clearance is mandated less than 2" overall room to move, plus room for padding in that space.  Cage needs to be forward of the helmet (think chin area) in case of a frontal impact, which is not up to par in our truck yet.  Left side and exiting becomes a problem, but it can swing open with the door so we'll be designing that soon.  

[Stoffregen Motorsports]

Don't burn out. Work on something else for a while so you don't lose your motivation completely.

[distributorguy]

I just put together a '68 Cutlass convertible for my wife, bought in August.  Rebuilt a good performance 350, added FITech fuel injection, buffed out a cheap 25 year old paint job, and rebushed the entire suspension.  I'm almost ready to park that for the winter and get back to work on the Datsun.  As soon as the weather turns, which normally would have been a few weeks ago...

[Stoffregen Motorsports]

How did you like the FITech? Easy to install? Price?

[distributorguy]

FITech is pretty fantastic.  $799 plus a new tank with a high pressure pump installed at $450 instead of their fuel command center, which appears to be problematic.  

Hook up the fuel supply and return lines, hook up 5 wires.  The car started on the 2nd engine revolution  and immediately started self-tuning.  No surprises.  No troubles.  Once you get out for a few drives, you can actually dig in and make manual tuning adjustments to work out small bugs.  I had a little too much accelerator pump at light throttle, and it just took a few button pushes on the handheld screen to fix.  Adjust the idle speed so the IAC pulses 3-10 times per second (just turn the idle screw).    I set it up so my wife can transition from her Charger to the Cutlass seamlessly, despite the 45 year difference between the 2 vehicles.  I'll be installing another in the Spring, hopefully by then the multi-port system is ready.    

[Stoffregen Motorsports]

I don't know if I buy the "self-tuning" thing, but I'll take your word for it.

 

That is pretty cheap though. I've got an old Chevy K30 dump truck that I use around the property for tree cleaning and moving dirt. Well its carb'd 350 is such a pain in the ass to keep running and I would love to do a simple EFI swap. It doesn't get used enough to warrant a full LS conversion, but this FITech may be the ticket.

[distributorguy]

"self tuning" just means it auto-corrects to reach the pre-set O2 numbers with and without load, plus variable (6) accelerator pump settings.  It works.  In fact, it works the same way any new car does.  These guys designed many OEM EFI systems, so they know the algorithms that work.  Better than the guys who built quadrajets anyway.  

[Stoffregen Motorsports]

My doubt lies in the cost. OEM's have thousands of hours spent in writing code and designing systems to keep the checks and balances.

 

The proof is in the pudding though, and if the ends user is happy, hat's all that matters.

 

Oh, btw. Re your PM, my Rover is slightly modified. No more Lucas electronics inside that engine bay. Thanks for the offer though.

[distributorguy]

I guess its time for an update.  The motor is almost ready to fill with fluids.  Brakes work.  Clutch works.  Cooling system is installed.  Fan and shroud installed.  Engine wiring done, short of making one more battery cable.  Its getting close to being a driver!  Just need to install the fuel system, likely to take place before the weekend is over.   [/url]">http://

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[Stoffregen Motorsports]

That header is HUGE!

 

Looks good. It's interesting to see a 620 in race guise.

[]2eDeYe]

Pics of the 68 Cutlass! I miss mine :( 

[distributorguy]

The header is sized for the race cam and port work in the head, which marries well with the DCOE 50's, not yet installed.  This is the tame 11.5:1 test motor to set up the chassis.  

More to come, as work progresses!  Too bad its "Production class" so externally, its stock with a hood scoop and lowered.  And a few stickers.  

 

The  68 Cutlass convertible, lame 350 auto:  

[/url]">http://http://s1148.photobucket.com/user/distributorguy/media/Datsun%20project/74834256-89C3-48F5-86E1-37CA0CE85DD8_zpsppoedpzg.jpg.html'>

[Stoffregen Motorsports]

Summer only car?

[distributorguy]

It was bought out of Florida in 1974 and hasn't seen a winter since.  Its a "driver" not as pretty as photoshop makes it look, but its fun and my wife likes it so its a "keeper."  I can't say that about the ratrod or the MGB or my Ford truck or the Datsuns.  My daughter doesn't think any thing is cool, other than a '59 Ford Victoria or a '59 Caddy or maybe a '64 Lincoln.  I don't know where I went wrong..   :poke:

[Bleach]

I'm late to the party but here's my contribution.

 

The 1979 Datsun 620 had a unique 5-speed transmission that year. It is the closest 4th to 5th gear change you can find in the OEM transmissions.

Here is a list of transmission and rearend gear ratios.

 

http://www.bleachgarage.com/620tech.html

 

The Z-car close ratios that was mentioned a year ago was referring to the 1981-83 non-turbo 5-speed 280ZX.

They had a taller 1st and 2nd gear so you basically had slightly closer gears in 1st through 4th. To make up for this, the rear diff was lower geared and in turn 5th gear was a much taller overdrive for better highway economy. So in that "close-ratio" 5-speed your 4th to 5th jump is large.

[Stoffregen Motorsports]

It was bought out of Florida in 1974 and hasn't seen a winter since.  Its a "driver" not as pretty as photoshop makes it look, but its fun and my wife likes it so its a "keeper."  I can't say that about the ratrod or the MGB or my Ford truck or the Datsuns.  My daughter doesn't think any thing is cool, other than a '59 Ford Victoria or a '59 Caddy or maybe a '64 Lincoln.  I don't know where I went wrong..   :poke:

Love to get me some Lincoln action. I desperately want a black on black on black '65 Continental convertible with big whitewalls.

[distributorguy]

The Z-car close ratios that was mentioned a year ago was referring to the 1981-83 non-turbo 5-speed 280ZX.

They had a taller 1st and 2nd gear so you basically had slightly closer gears in 1st through 4th. To make up for this, the rear diff was lower geared and in turn 5th gear was a much taller overdrive for better highway economy. So in that "close-ratio" 5-speed your 4th to 5th jump is large.

That's the backup transmission that's in the truck right now.  We can't even consider using 5th gear, so its a fair choice - the best of the 4 Datsun transmissions currently littering the shop.  I think if we hit 5th gear at 125 mph, the truck would decelerate.  To my knowledge, no one uses overdrive with under 1000hp.  

[datzenmike]

You could change the differential gear so 5th could be used. Not advised to stress the 5th gear like that but you could.

 

My info shows the '79 620 wide ratio fifth gear as a 18.7% drop from 4th. Same wide ratio as used in the Z22 powered S110 200sx and the 720 truck.

 

The mid ratio used in the late 280z, first year 280zx, 810 and Maxima and Z20 S110 200sx was 13.6% OD.

 

 

You can check by placing in 5th and spinning the input 20 times and counting the output turns. 20 in at 18.7 OD is 23.64? out

[distributorguy]

If anything, I'd take the shallow 5th gear out of the transmission that was in the truck (must be around 93%?) and put that into this 280Z transmission.  But I WILL NOT use overdrive, so its a moot point.

[datzenmike]

Agree not strong enough.