Autocross/Street Handling '72 510 Wagon

[bonvo]

That is all relative to what you want out of your car. I have heard of way more success stories autocrossing with an L series than anything else. To me, the VG is the heaviest option over the front wheels.

 

If moving away from the L series, and retaining handling is key, my choice is the ca18det as it is even lighter than an SR.

 

But really, a nicely built L20b sounds like an the perfect plan for what it appears you do with your car.

 

ya know everyone says this but the biggest contributor to the weight is the TRANSMISSION which is in the center of the car meaning that handling isnt effected much i have talked to alot of people who are running vgs and they have all said that the balance of the car didnt really change

[troyt]

<< I've also heard that an open chambered U 67 head is better for l20's, since they retain a larger amount of displacement that way. >>

 

I hate to say it, but you've heard wrong. The engine displacement is created by bore and stroke, the compression ratio is created by the piston top shape and cylinder head combustion chamber shape. Dished pistons and a small chambered head can create the same CR as domed pistons in an open chambered head, all with the same engine displacement. Combustion chamber design not only effects compression ratio, but flame propagation, which leads to better fuel burn and fuel effeciency. The reduced squish area of a closed chamber A87 combined with some flattops slighty below deck height make for a great compromise between power, effeciency, and cost.

Properly setup Hitachis (the proper Nissan name for what everybody calls SUs) and Weber downdrafts can provide good power and good fuel economy, same goes for Mikunis and Weber sidedrafts. Most people who complain about poor fuel economy from a dual sidedraft setup either a) have not set them up properly, or B) always have their foot buried in the throttle to listen to the intake roar. And usually its a) and B) combined ;-)

Since you're already going with a 5 speed for crusing fuel mileage, why not go for the extra power (and cool look) of a dual sidedraft system for the competition aspect of your goon? And if a little extra torque would be nice, use a Z22 crank in that L20b, nothing replaces displacement.

[coolerow]

Great thread subscribed!

 

Don't know if I missed it but can you tell me where you got your traction bars and composite leafs?

[Son_of_a_Datsun_Guy]

The traction bars were designed and mostly assembled by Kelvin Dietz, he just did a one off and a few of us go in on them with him.

 

The leaf springs were from flex form, it's a small company on the east coats, Georgia I think.

 

http://flex-form.com

[Bob3]

Love it!

[Son_of_a_Datsun_Guy]

@ Bob3: Thanks, I your stuff is just way too cool, the MX520 is so insane, and totally awesome. Your 68 rat was the perfect example of ratsun to me.

 

Found an action shot of the wagon in some older pictures, in the caravan on the way to the bayline gathering:

 

[Son_of_a_Datsun_Guy]

And some progress tearing down and diagnosing the L20... not that it really matters everything is being redone anyways.

 

Head off

 

 

Looks like a blown head gasket (probably why it was in the junkyard) And the bores look good, there's no lip from where the piston stops on the upward strokes.

 

 

 

 

and that's where I left it last night, going to be gone next week so it'll sit for a bit

 

Couple other things that I forgot to mention earlier:

I've put an internally regulated alternator from a VG30 (it's a bolt in, and only a couple of spliced wires)

 

aaand... I forgot the other thing

[Son_of_a_Datsun_Guy]

Okay so I will edit this post with pics tomorrow, too dark out to take them now.

 

While I was gone at BAND CAMP yeah you heard that right band freakin camp. I'm a band geek, get over it. While I was gone the wagon was over at Luke's shop, and the oil leak finally got fixed, and while it was there I learned that it's dangerous to leave cars around him... he just starts to fix things haha.

 

So I got back and the rear is now 1/2inch lower (3 1/5 in total now), the front sway bar is now modified so it not longer hits the crossmember on bumps, and there is no more clunking in the struts. Luke if you ever read this you are awesome, you do things that amaze me. And your dad is really funny :rofl:

 

However, the car will need some modification because now the suspension allows the u-joint connecting the driveshaft to the diff to smack and grind against the floor of the car right underneath the back seat if I hit a bump at freeway speeds, which is a lot. So gonna notch that and make it stop that pretty quick.

 

Tonight I got bored and didn't have much school work so I got some work done on speakers, and now have one of the 6x9s in the rear cargo bay... yeah just one, I decided to stop using power tools at about 10 tonight. But it sounds awesome, and the other one will go in on Wednesday!

[carterb]

However, the car will need some modification because now the suspension allows the u-joint connecting the driveshaft to the diff to smack and grind against the floor of the car right underneath the back seat if I hit a bump at freeway speeds, which is a lot. So gonna notch that and make it stop that pretty quick.

 

 

Time to raise that tranny tunnel. I'm going to have to do the same to mine to get it to the ride height I want. I don't mind a little rake on a wagon but you've got to get lower than 3" without driveline issues. Can this be done without having to modify the rear seat as well?

[Laecaon]

I have yet to really bottom out on any normal bump, just construction bumps at night when they forget to put up a "bump" sign. I have bad diff slap when launching in first.

 

I might add as well, My differential bumpstop the one in the middle of the car, was touching the diff when parked on level ground, So I cut an inch out of that to have some suspension travel again.

 

Back is lowered by simply flipping the overload spring to the top of the pack and upside down, so no blocks...

 

[Son_of_a_Datsun_Guy]

I must have been rising on the hairy edge for a while, because it's pretty bad now, I'm thinking that I'll put the rubber snubber back in just shorter in addition to notching the floor. The traction bars have kept the diff slap away though, which is nice

 

@Carter: I haven't look at it without the seat in, that'll be coming up later this week, if I need to modify the seat I will, but I like having the extra seats, so I'll find a way to keep it there. In terms of actually getting around he problem completely Ive decided that if I was going to do the leaf springs again, I'd get them in a higher spring rate, and lower to begin with so I didn't have any blocks, I think that the higher sprin rate will help with the bottoming out in general....

[Laecaon]

Have you seen greengoons thread? He posted a few pictures.

 

Basically he cut the floor under the seats, raised it a little bit, added new material in, And then cut out the notch in the seat pan. He says the seat pan is still ridged enough.

 

Well I found it, but there are a ton of photos, so I am just going to link to it.

 

http://community.ratsun.net/topic/26747-the-greengoon-build-thread/page__st__20#entry391997

[jrock4224]

green goons thread has some good picks of how he modded his seat pan andit didnt affect the fitament...he also covered his tranny tunnel raising i nthread also....

 

laecon you need a couple inches more in the rear those weds would look so crazy about a 1/2 off the lip ...your car would be so dope wait it is dope to begin with spent

[carterb]

Have you seen greengoons thread? He posted a few pictures.

 

Basically he cut the floor under the seats, raised it a little bit, added new material in, And then cut out the notch in the seat pan. He says the seat pan is still ridged enough.

 

Well I found it, but there are a ton of photos, so I am just going to link to it.

 

http://community.rat..._20#entry391997

 

Awesome! Thanks for the link. No guess-work there anymore.

--carter

[jrock4224]

holy shit i never refreshed my browser and said the exact same thing as laecon....only a hour later.. surry guys... but hes right theres some good info on his thread

[DaBlist]

"ya know everyone says this but the biggest contributor to the weight is the TRANSMISSION which is in the center of the car meaning that handling isnt effected much i have talked to alot of people who are running vgs and they have all said that the balance of the car didnt really change"

 

Back to class: Losing weight at the ends of the car has a much greater benefit than from the middle of the car which is the reason for mid engine sport cars. But hey, what do we know anyway. The Germans think a modern sports sedan should weight 4000lbs, Ha.

[jrock4224]

"ya know everyone says this but the biggest contributor to the weight is the TRANSMISSION which is in the center of the car meaning that handling isnt effected much i have talked to alot of people who are running vgs and they have all said that the balance of the car didnt really change"

 

Back to class: Losing weight at the ends of the car has a much greater benefit than from the middle of the car which is the reason for mid engine sport cars. But hey, what do we know anyway. The Germans think a modern sports sedan should weight 4000lbs, Ha.

 

this is why i drive my goon from the rear trunk... that extra 240 lbs over the axle really helps drive off....lol....soadg..will u adopt me as your father ... i always wanted a son with dope taste in cars...lol

[Eagle_Adam]

great thread - subscribed :D

[Son_of_a_Datsun_Guy]

Eagle_Adam: Thanks!

 

jrock: That'd be chill, and I know the height feeling, I'm 6'5" and can reach the pedals and the wheels while sitting in the back seat :rofl: Your engine bay is the shit by the way.

 

I've definitely read through Greengoon's build at least a dozen times, can't believe I didn't remember what he'd done, I think I'll steal that idea now that he's got the credit in my thread.

 

 

also, Jack White sounds awesome in my wagon rolling down the street...

[jrock4224]

hey man update your shit......lol.... seen u on another thread like three points....this one is for sale.....building a new one for more carb clearance to build a air box...didnt know if u had one or wanted one...this ones aluminum powdercoated silver ....i could do it pink if you'd rather...lol.... it's built for troy ermish plates...and has a inner support piece plate for the cowl area...it also is real close to the wiper motor but i can dimple it to clear and recoat it .......i was gonna throw it up on the fer sale section as soon as he makes the new top plates for the v2.0 bar for his carb set up...side note ... his honda buddy almost had him convinced to build a steering box support off this bar... i said brace box seperately....no extra monkey bars to the cross bar...

 

[spec-bre]

That strut brace is sweet!!

[ol' 320]

Do you plan to have your friend Luke raise the rear tunnel on your wagon? What is your rear gearing?

[Son_of_a_Datsun_Guy]

Okay, so I haven't been updating... obviously. Just have a lot of balls in the air right now, juggling school, music, college apps and tons of other stuff.

 

But I have been getting things done on the car, slowly but surely.

 

pictures of the 6x9s

 

 

 

I do need to finish the panels and get them in, and I think that they might need an additional brace, give the whole thing a third point of contact to the car that isn't just the ABS panel.

 

It's going to get worse before it gets better

 

took the back bumper off to do some more paint prepping, I'm going to spray down below the hatch too, patch up some bondo, so on and so forth

 

Those reflectors underneath the tail lights are going to stay off too.

 

Okay some interesting stuff, this is what the car looks like lowered the last bit in the back, just enough to cover the very top of the tire with the arch.

 

Back: new

 

compared to front: the same as before

 

 

Moving on, more stuff to talk about:

Do you plan to have your friend Luke raise the rear tunnel on your wagon?

 

Yes! in fact it's already happened. got the car back last week (Again I have to give Luke props, his stuff blows me away)

 

The entire transmission tunnel has been raised, in fact Luke made a completely new one. He doesn't do anything halfway :thumbup:

 

 

This bit right here, absolutely makes me giggle

:hyper:

 

So cool, a big part of me wants to just leave the carpet out so that everybody can look at that and be jealous. Thanks Luke!

[Stupid_fast]

So jelly. :(

[Draynor]

Sweet! I want to do this soon...