I noticed on your swap site that you had the F/R weight distribution on you car 46/54 before the swap and 48/52 after.

Now, I have a Car and Driver article for the s13 that has the F/R weight distribution at 52.8/47.2 stock. This seems to make more sense as the engine is in the front and the only time I've ever seen rear bias is in mid- or rear-engine cars. How did you come up with these figures for yourself and did you do anything to the car that would cause it to have such a differing bias (53/47 to 46/54 is a pretty decent weight shift)?

I'm sorry, I'm not trying to start an argument, but it just seems as if your site presents the swap as helping to balance out the car, something I find difficult to believe when adding a heavier engine to the front of the car (I'm not trying to say adding an RB would be absolutely detrimental weight-wise, just found your figures a little odd).

 

I got my weights by going to a local car scale at a truck stop. I weighed from where my driver's door is to the front and then from the driver's door back for the rear. This means right where the back side (farthest from the front) of the driver's door is. That's where I got the weight since that's about halfway through my car. Then I took my weight and subtracted it evenly from both sides since I was sitting on the dividing point. My numbers can be slightly off, I'm about 160 pounds, so front/rear, whatever lol. That's just what mine weighed in at. I also have a LE which puts more power features in the car that standard 240's don't have.....that may be a small part of it? Sometime I'll do a 4 corner weight and that will be accurate, but until I find a 4-corner scale, this weight is the best I've got.

Night

 

Is the C/D spec list from the manufacturer or their own? It could be a "dry weight" distribution. Gas in the tank in the rear of the car could offset the distribution. As could spring rates(ie. corner balancing). And many other things.

 

Ok, that's what I figured. A four corner scale would most likely tell a different story. While I believe a 2% shift to the front after the swap, I just can't believe it was rear-biased to begin with. But a 2% change is encouraging as it's relatively negligible.

 

jtsarnak,
whats issue of C/D features the s13?

 

I think the whole gas thing makes a difference as well....and I think Nissan weighs them before they get a spare tire and jack in the back as well which could also make a few pounds difference.

16 gallons x 8 pounds/gallon = 128 pounds
Tire - 25-30 pounds
Jack - 5 pounds

So you could be looking at an extra 150-160 some odd pounds over factory regs depending on what they weigh to get those specs and what's in the car when it's weighed.....anyone know what is involved when cars are factory weight rated?

Night

 

C&D's road test was Feb '89. It was also featured in July '89, Nov '90 and June '91.

They road tested the s14 May '94.

If you'd like to see the scans, go here:
http://www.**********/links/magazine/

There's a bunch of other articles too, nice resource.

 

That could make some difference. 160/2958 (curb weight plus the 160) = .054 or 5%. Now it wouldn't be a 5% shift from front to rear, so it probably make a little over 3% as a shift goes. That'd be a 52.8/47.2 --> 49.8/50.2 which is pretty damn good, chalk up the rest to the inaccuracy of not having a four corners scale.

But then again this could all be speculative because I have no idea where the C&D figure comes from. If they measure it, chances are they have gas in the tank and maybe even a driver. If it's just the manufacturers spec, I'd venture to say your figures are pretty close to the truth in that the RB would have little to no effect on balance (49/51 to 51/49, big deal).

That's enough theorizing for me.

 

Spring rates will not change front/rear weight distribution at rest.

Corner balancing is diagonal across the - doesn't change front to rear bias, just distributes it differently side to side.

A tank of gas can certainly make a difference though.

-Justin