Building a competitive Autocross 510 (sedan)

Post by **5teN** » 18 Oct 2003 17:45

I'm looking for some insight!

What class would you aim for?
What mods would you do?

I think Byron and Richard are set that a turbo'd L18 powered 510 would be a competitive autoxcar. What class would that put you in? What suspension mods could you do?

I have a flared 2 door I'd love to do something with. D/MOD in the wagon sure isnt going to get me anywhere!

Cost would certainly be an issue...But I'd still like to hear all thoughts!

Post by **510rob** » 18 Oct 2003 17:51

psst... wanna buy a turbo L18?

its got lots of good stuff in/on it...

Post by **5teN** » 18 Oct 2003 17:58

I'd sure like too, but i don't have much money (blah blah, poor student, starving living in box(my 510! HAHA)...). SO unless you want to give it to me it probably won't actually happen

hehe

Any autocross 510 building tips?

Derek · Post by **Derek** » 18 Oct 2003 18:13

I'm going the FSP route with an EFI NA L18 -- but since I don't really know anything about building an autocrosser (this will be my first attempt) I can't give much in the way of tips.. I think it would be hard to stick in SP with a turbo, according to the points system. Although, turbo Miatas fall under SP, I guess you just need to take it easy with other parts of the car.

Boaty · Post by **Boaty** » 18 Oct 2003 18:42

I don't know much about autocrossing, since I've never been in one.

But, my guess would be the usual electronic dizzy, Pertronix or MSD?
A good, balanced port-matched head and manifold running dual carbs (precision tuned)
Full port and polishing
New valves (oversized), and 3-cut racing seats
Polished Valve faces (Heard that helps, I don't know how, tho.)
Racing Piston Rings. (I Heard you can get up to an extra 2HP by using Deves Racing Rings. http://www.paeco.com - they have them.)
A 10.5:1, maybe 11:1 compression, forged pistons.
High-RPM Racing Valvesprings
Aluminum Retainers, Hard Seats
Maybe a stroker kit for your little 4-cyl? http://www.paeco.com - THEY HAVE THEM!!!

If you really wanted to spend the extra MOOLA, you could get Titanium connecting rods, some titanium retainers.

Run a 2.5" or 3" exhaust, super turbo muffler.

I would run super stiff suspension with really grippy tires (durh..) with a limited slip 4.65 (or thereabouts) differential. ( She wont be fast on the long-stretches, but she'd kick your ASS light-to-light.. or between the cones.)

Coilover suspension, corrected camber (Penultimate Crossmember?)
Camber plates and spacers in the front... the usual lowering BS.

Nismo Close-Ratio transmission w/ short throw shifter.

Oh yeah, lots of weight-removals. small 4 gallon fuel cell, no seats (or racing front seats, no backseat.), etc etc and so on and so forth.

And remember to add that "L-series inside!" sticker that adds like 600HP.

That would be like.. ultimate autocrosser. I dunno tho. I'd LOVE to have that as a street car. I would be like.. "Buhbye, HonduhZ."

Post by **bertvorgon** » 18 Oct 2003 19:20

You SHOULD build the best suspension you can!!!!!! Period!!!! A good suspension will blow away any hi-horsepower, ill handling car ANY day. After slaloming for 25 years I have seen it all. Handling buys you more time than horsepower. You want as much bottom end torque that you can get, with whatever engine package you decide to do. Buy the best, stickiest ties you can. This all boils down to how serious are you, in terms of winning, or "just for fun". I can think of many times I won events against cars that seemed so intimidating because of their perceived power, but ultimately could not handle.
This is more so these days because the slaloms are SOOO SLOOOWWW and tight. When we had the WHOLE if the Boundry Bay Airport, I would be in 4th gear at 80 MPH! That was fast. Do not get me wrong, power is good, but a really well set up car can maximize the power you do have. Look at the Miata that got FTD at the Nissan event, with Sean Kierney in his 1200 right behind. That was handling.

Post by **510rob** » 18 Oct 2003 23:24

from what I remember someone telling me about autocross rules a few years ago

#1 - motor swaps put you in GTX automatically, so you might as well swap in the BIGGEST motor that's still lightweight...

#2 - a very few 510s were brought into the north american market in 1973 with L18 engines from the factory; this was specifically for rallying rules, but it kicks the door wide open for everything else too, IF you can prove to the event steward/host & your fellow competitors that 510's were available with the L18 from the factory, which would make it a stock motor, and NOT a swap...

#3 - you will get less class-changing/upgrading points for a turbo motor than you will for dual sidedraft carbs... I think the trick is you have to make the turbo motor work with a stock Hitachi carb - that way, you don't have a "modified carb".... If I remember correctly, a modified carb adds 2 points for the actual mod away from stock, then 1 extra point per carb throat = 6 points for dual webers/mikunis? Turbo adds 4 or 5 points, or 2 or whatever it was... read the rules VERY carefully for the little loopholes like that, and "fuel additives" (right Keith?)

As Keith said, handling wins autocross... a drag car on mickey thompsons is never gonna beat a stock honda civic around a bunch of cones...

by avoiding dual sidedraft motors, you can save points for the handling modifications and gearing changes that will get you quicker acceleration. Another point to look at is getting the LIGHTEST flywheel & clutch possible, and the lightest rims possible too... its all mass that needs to be accelerated and decelerated...

...it all costs too much money

Keith, do you think they might let me run my YZ250 at an autocross? ha ha ha!! (I don't really think so, and I don't think I'm that bold/brave/stupid)

I remember seeing a Formula Atlantic car with a Lotus Europa body and a Buick V6 motor at an autocross out at UBC in the very early 90's; it was considered to be a "modified vehicle"... but it was fffffFFFAST! Keith, I think that was the day your car was running about 25psi with a busticated wastegate?!? ...writing that makes me feel really old for some reason (was that "the good old days"?)

Rob

Post by **5teN** » 19 Oct 2003 16:23

Thanks guys!
What about specifics? What engine would you run? What suspension?
Would you keep it 510 struts to stay in a lower class? Would you run lowering springs or would you go for coilovers (putting you in a different class?).
I'd love to hear your ideas!

Post by **bertvorgon** » 19 Oct 2003 17:51

Spencer, why don't you stop by where I work and I can go through the rule book with you. You are allowed only so many preparation points for a given class. You SHOULD do this first, then we can look at your budget and see where the dollars/time is best spent. I would be glad to do this with you. Any engine swap puts you into C-MOD! That is a tough class, believe me. Thats where I run, and any one serious, which they are, is on RACE TIRES< REAL RACE TIRES> Phone me at home or at work

Post by **bertvorgon** » 19 Oct 2003 17:59

Rob, it has been awhile! GTX is for the hillclimbs, C-mod is for the slaloms. Yes that WAS the day the wastegate had a signal problem. Wow , was 25 lbs exciting. One year at Knox, some asshole TURNED UP the boost control knob in my car. When I left the light I thought to myself the moter really feels strong, HE, HE HE. Did I ever get to turn one fast...then coming out of the corner it accelerated so hard... and then started to detonate...big time... I lifted and got back on the throttle, looking at the boost gauge, 22 LBS boost, damn. Cost me a run. But man, did that thing accelerate. Good thing I can practice self control, what with that little knob beside me! NO I do not think you could race your bike, I would like to se that though.

Boaty · Post by **Boaty** » 19 Oct 2003 22:47

Hm. I don't know anything about the turbo preperations people install.

The boost control - is that basically just a flow-through valve that shuts off at a given pressure, or lets everything under a given setting pass through?

If you could adjust the pressure manually from the driver's seat, could you in essence turn the boost up on teh straight aways, and drop it down to prevent decellerative-detonation? I probobl overshot what a boost-controller valve is...

Meh. Wish I had a turbo. I would like to get the entire setup from down south (racetep.com) in California, they supposedly have everything you'll ever want or need for setting up an L-Series with turbochargers and dual webers, including all the plumbing for exhaust and intakes. Very pricy, too. I believe almost $2000 for a setup, not including carbs, with a T3 Ceramic-bearing turbo. Maybe somebody can post a new turbo-tech thread in the forums? Just for newb's like me. Thankz.

Post by **510rob** » 20 Oct 2003 00:40

Steve,

With respect to your wanting a turbo q & a forum, I beat you to it this afternoon...
c
heck the Datsun PL510 Technical Forum for a "sticky" topic called...

TURBO Q & A FORUM

maybe ask questions in there to centralize the thread a little more...

Robert F.

P.S. - does anyone know what the hell is the sticky moniker is supposed to imply?

krackerx7 · Post by **krackerx7** » 24 Dec 2003 18:55

is there anywhere online that has all the classes and rules?

Post by **bertvorgon** » 24 Dec 2003 21:55

If you are on the lower mainland you can borrow my rule book. that is most important as i said above, then you can decide what you are up against. it is based on a point system. Most of us have done mods that bump us real fast into a level of competition that makes you have to decide if it is for fun or for serious...or both!

Post by **rnorrish** » 26 Dec 2003 14:02

It's always the motor that gets everyone. As soon as you have a L20B or bigger, you are in C-Mod. There a few of us hanging on to L18s just for this purpose...

I remember that turbo L18 plan...one day....muwahahaa! Those Sentras and Forsa's are going down! FSP sure is nothing spectacular - except Datsuns.