LS1 Powered S14 by SicBastard

12 minute(s) of a 390 minute read

I spoke to Joey at Ohlins USA again today. Here are the Shock dynos from my new coil overs. He told me that they put 'em up on the dyno when they first go in because they had never seen these before in person, and were wondering what they would do. 

There are runs for both rebound and compression at full soft and full hard (thus the 4 lines per graph). I'm hoping to get a dyno graph at each seperate setting for each corner later, mostly to just match the dampers left to right. Ohlins assures me that they will be the same L2R, but I'll believe it when I'm holding the graphs in my own hands. I'll shoot some PMs to those that know more about reading these than me and we'll all see what we can learn.

Fronts:

Rears:

1/15/09

Tim,

What exactly are CVP files? Will I need a special program to read them? If you click on the pictures above they get a little bigger, at least enough to read the velocity and force axis numbers. Lemme know I can call Ohlins later today.

David,

I was half joking when I made that post, and I've always loved the lay out of the s2000 no doubt. Matter of fact the s2000 is set up a lot like an old 240z. But if you want to get technical, it's safe to say that my engine's cg is behind where a front axle would be, so... It's all semantics, regardless, these things rotate great when all is said and done. And even with my monster radiator I'm hoping to have <53% of the weight on the front when complete. We'll see!

That post was actually a copy of a post I made for MMDB's LS1tech thread about his LS1/240sx build

My 240sx / S14 LS1 Swap - Progress *56k beware* - LS1TECH

MMDB post 264: "Update: It's been bout a year since I've completed this swap. The swap has proven to be very rewarding reason being I haven't had the engine fail on me and I've been able to have fun with the car almost every day going to and from work (30 miles each way) and more. What I want to bring up now is handling. GIGPUNK's post (261) illustrates the position of the motor within the chassis, which leads to a few things. First off, the t-56 being heavier allows the 240 to rotate much more. This could be good, and this could be bad. 

In my case I was running 11kg / 9kg spring rates front and back respectively, which proved to be TOO stiff! This was bad. The car found itself difficult to plant the rear tires under acceleration. During corner exit as well, the car wanted to slide out. 

What is good is that the car WANTS to rotate. But with such high spring rates it's difficult to put down the power and the car just wanted to slide whenever applied. 

To counteract the negative affects of oversteer and prevent it I dropped the rear spring rates from 9kg to 6kg, and dropped the front from 11kg to 9kg. I also lessened the rebound dampening (my shocks do both rebound and compression) which allowed for smoother weight transfer during mid-corner to corner-exit transition. Removing the sway bar in the rear helped a lot as well (basically a sway bar increases spring rates during lateral weight transfer). 

I thought this post might help whom ever is battling this issue and wants more grip. Of course there's many other ways to tune the suspension such as running a bigger sway bar up front, but for my purposes changing spring rates was more convenient for me. "

You'll also notice that Wikipedia lists my car as being FMR

Mid-engine design - Wikipedia, the free encyclopedia

Oh I bust me up.

1/20/09

Backspace & frontspace!!! 

This is a repost from one I made for the max rubber thread:

I think the reason that this topic seems so hard to nail down is that there are really two dimensions to a wheel that you need to know on a 240sx, one objective, one subjective.

The objective measurement is the distance from the hub face till you hit something on the inside (like a control arm or the strut). This is also referred to as BACKSPACE. This distance really doesn't change much, even between s13 and s14. Sure an 18" wheel may have a bit more clearance than a 16" wheel to the control arm, and 5* camber may get you in more trouble with your strut before 1.5* will. But for the most part, this number doesn't change, and is what we should be comparing!

The subjective measurement is the distance from the hub to the outside of the wheel. I've never seen this distance labeled on a wheel diagram, so I'm going to call it FRONTSPACE. This is the only thing that should be changing depending on overfenders, stretch, monster rubber/buldge, S13 vs. S14, roll, pull, etc. I find FRONTSPACE to be a matter of taste, as such it should be calculated from proper measurements and good wheel/tire size with accompaning pictures as have been provided in this thread already. Bust out the calculator people! 

Once you know what the max backspace IS, and what frontspace you WANT: bust out the calculator again, and you've got your max wheel.

Almost all of these pictures and descriptions were pilfered from this thread. I'll break em up by front and back, because I'm trying to define max backspace per end with this post.

FRONT

backspace 153mm

I think that this first picture is the most helpful. Yes the wheel is hitting the strut at exactly 153mm, but it wouldn't be with shorter springs/taller ride height/small spacer.

backspace 157mm

backspace 149mm

backspace 157

backspace 159

REAR:

backspace 172mm

yall may not be impressed by this cat's "flushness", but the sucker goes deep!& those are 275s (on 17x9.5 +39), look how much room there is on the frontface still, and those fenders don't even look rolled! This echoes my earlier post that there is no excuse for an s14 to be rolling around on anything <275s in the rear.

backspace 173mm

Again one of the most helpful pictures that our fellow zilvians have bestowed upon us! Basically this tells you that unless you're running skinny ass stock type dampers, or relocate your rear damper, that you will NEVER get much deeper than a 178mm backspace!

proving my backspace is universal idea here's a couple s13 pushing the limits:

backspace 173mm

backspace 174mm

Putting this together took a bit of work, but we now have half the equation. 

MAX backspace Front~ 150-159mm

MAX backspace Rear~ 172-179mm

Calculate the backspace, of a zero offset wheel by multiplying your rim width in inches by 12.7mm/in

9in x 12.7 = 114.3mm 

Add that number to your current offset to get your wheel's actual backspace.

114.3 + 22 = 136.3 mm

subtract your back space from the theoretical max posted above to see how much clearance you currently have on the inside. or just get under your car and measure it with a ruler/caliper. I predict you'd find these clearances if you did so. Let me know if you find different.

rear 172-136.3= 35.7mm

front 150-136.3= 13.7mm

1/23/09

I went crazy and figured out the max wheel/tire that could be put under a 240sx. There have been a million posts asking, "will this wheel/tire fit?" Now you know.

MAX backspace (Same for s13 and s14) 

Front~ 150-159mm

Rear~ 172-179mm

MAX Frontspace [backspace + frontspace = wheel width in mm]

S13 Front 95-105 (looks great at 99)

S13 Rear 80-95

S14 Front 109-116 

S14 Rear 97-117 (110 really is perfect with a good r+p)

I also downloaded the Roehrig shock/spring dyno software and thought the displacement graphs might be helpful to some in addition to the above (post 155) velocity graphs.

front

rear

I think it's interesting (and probably most usefull) that the adjusters only significantly affect the low speed damping. The small change they make in high speed is one of the few faults I can see in the ohlins; at high speed the adjusters actually do the opposite of what they are supposed to, but to such a small degree (percentage) that I don't think it is significant. Anyone disagree?

1/28/09

I'd like to share with all of you a quote from my chief of surgery, "Are you functionally retarded?"

That's all I have to say about that...

In other news, here's some new pics:

The Oliver rods came back. Oliver is a class act! Every rod came back cleaned, oiled, and with each rod individually sealed in a heavy duty clear bag. Here's a pic of the recently added lube tubes.

To the front face of the block was 14.125" behind the core support. I think that distance would be a little bit more in an s13. Also notice how rust/battery box free my engine bay is! Drilling that tray out was not fun!

I was asked to quantify my blocks placement so here ya go. Looks like a little less than 7" from the top of the block to the seam. With a 2" cowl I'd have a whole foot of clearance!

At the front/top edge of the block I currently have 8" to the bottom of the hood. This high mount alt actually fits! But my GTO alternator is too big for the f-body alt bracket, so custom mount to the lower, driver side motor plate is coming up. Anyone need a billet, passenger side alternator hi mount for (I was told) a vette offset?

Hey guys I'm trying to figure out the length of the spacers that I need to mount the alternator to the motorplates. I measured the above alternator mount that I randomly got on ebay and will not be using. It puts the inside of the belt exactly 4" from the front of the block. Anyone know if that is F-body or Y-body offset? 

I finally paid for the ohlins today, it looks like they really did loose my rsr springs, tender springs, tein camber plates, and custom heavy duty crate. They are going to give me some new tender springs as I was planning on using them on the miata, and they knocked another $100 off the price. That won't exactly cover another set of camber plates and springs, but it's time to cut and run.

And this is bitchin: Active aerodynamics for your track day car!

http://aeromotions.com/gallery/

I also have gotten tired of running to home depot to not find the bolts that I need and am thinking of getting a monster/complete set of nuts and bolts from Fastenal

3850 Pieces Asst. Bolts Nuts and Washers M4 to M12 | Fastenal

I've also been sourcing endlinks and threaded hex rod so stay tuned for some custom sway bar endlinks and home made adjustable suspension arms; part numbers to be included!