is the handling really affected due to the unbalance?

 

that weight dis. isnt that bad. a CF hood might take 1% off the front?

 

Handling will be affected but not drastically. Front to rear ratio can easily be fixed with higher than normal spring rates in the front. Basically if you want to correct the ratio through weight loss/transfer, you will either need to lose 100lbs in the front or transfer 50lbs from the front to the rear. Hood, Bumper and Fenders will help maybe to about 20lbs at MOST

-Bluefire

 

A Full Tank Of Gas Would Have Balanced The Car Until You Got In..... You Also Need A Full Exhaust Hell Thats 50 Pounds Right There.

If You Had A Rb20 In There It'd Be Alot Lighter Total Weight Because Of The Transmission.

 

A full tank would change the weight some, exhaust not that much only the weight of the portion that is behind the rear axle. And as for having me in the car, it does nothing to change front-rear weight, it really only changes cross weights.

I wish someone with a 20 and 26 would weigh there cars also to see what the difference is.

-Bluefire

 

i ran 8/7 springs in my silk roads when i had my s13.
handling felt just about the same as my ka, if not better.
the silly myth about the rbseries being hellaciously heavy is just that, silly.
proper suspention set up will compensate just fine.

 

Things to do:
Replace you cast iron manifold with steel or Ti ($$$). Replace your hood, bumper, and fenders with CF. Increase spring stiffness in the front.

Things notto do:
Drain oil or coolant. Shave down the block. Have a oneoff aluminum block made with sleeves ($$$$$$$$$).

 

Half Tanks Is 7 Gallons.... Gasoline Is 5.5 Pounds Per Gallon Roughly (depend Ons Addatives And Octane) 7 X 5.5 = 38.5 Behind The Rear Centerline Now Add A 10+ Pound Muffler/exhaust System And You Got Your 50lbs.

And When Altering Bias Its Everything 8inches Behind The Front Centerline Forward / 8inches In Front Of The Rear Centerline Back Will Alter The Bias

Try It: Mount Heavy Magnets (rare Earth) In Those Areas Described And You'll Notice The Opposite Unaffected And The Arear Bias Should Change.

 

Project, you would need 100lbs, only 50 if you took off the front and added 50 to the back.

 

HOw about relocating the battery to the back also, that would help a bit.

 

HOw about relocating the battery to the back also, that would help a bit.

already done, see first post

Trunk Mounted battery

 

Project, you would need 100lbs, only 50 if you took off the front and added 50 to the back.

Just tie 2 mid sized dogs to the chassis in the rear. It's like AWD! If you live in a snowy area, make sure you get sled dogs. :heyhey

 

I think i'll weigh my car soon enough

 

im with opelock on the dogs - go to the pound there free - so you get a better handleing car - plus some cool dogs for free!
i would go with rotwilers - they also act as a car alarm!
- but seriously spring rates would help - blown shocks with drop zone springs dont - thats what my bucket came with!! AHAHAHAHAH lol

 

Just tie 2 mid sized dogs to the chassis in the rear. It's like AWD! If you live in a snowy area, make sure you get sled dogs. :heyhey

Then you would have to make some kind of alarm, so people don't steal your dogs.

 

I don't have dogs, but someone go take their dogs and do this just so you can take a picture...lol

 

Well If You Did A Cf Hood And Stationary Headlights You'd Get Closer To 50/50. But 50/50 Weight Distro Isn't Anything All That Special... Total Weight Has Just As Big Of An Influance As Weight Distribution.

 

Has anyone seen Best Motoring 6?

The designer of the 350Z claims that he made the wieght bias of the 350Z to be 53/47, because:
1. it adds more traction to the front when braking
2. Under acceration, the weight shifts to the back

He claims that it's better than 50/50 of the s2000, rx-7, etc


I dunno if I believe him entirely myself, but it's something to consider.

 

already done, see first post

ooops.. over looked that. :greddy:

 

50/50 Isn't Always Best.... It Depends On The Driver And The Attitude Of The Car Really.

 

Everything really depends on what you plan on doing with the car. Obviously with more front weight the car will tend to understeer. But a small percentage over in the front can easily be corrected with suspension work(ie higher spring rates in the front.) But this also affects the way the car reacts in turns. For example, using higher than normal spring rates to compensate for the heavier front, will mean more bounce in the rear.

To be blunt the sr is better suited for handling. BUT that doesn't mean the rb has bad handling. It just means that the RB needs a little more suspension work to get to handle as well as an sr. But to me the increased power potential the RB has over the SR more than compensates for the slight(and I emphasize slight) lack in handling.

-Bluefire

 

You're correct in saying that weight distribution (static) has little bearing in the way that the car handles. Whats truely important is the amount of weight that the % is determined from.

Ex.

You have one SR powered car that has a static weight distribution of 54:46 (Car 1)

You have one RB powered car that has a static weight distribution of 54:46 (Car 2)

Car 1 weighs 2460 lbs.
Car 2 weighs 2660 lbs.

Now, both cars are limited to the same tire sizes correct? Lets take this setup.

255/40/17 94Y
275/40/17 98Y

94 = 1477 lbs. load rating
98 = 1653 lbs. load rating

Given for a tire the friction gain curve (traction gain) is linear until about the 73% margin within it's load range.

Now lets figure the car's standing load.

Car 1:
Front - 664 lbs. per tire (rounded down)
Rear - 566 lbs. per tire (rounded up)

Car 2:
Front - 718 lbs. per tire (rounded down)
Rear - 612 lbs. per tire (rounded up)

1477 x .73 = 1078 lbs.

Average weight shift is about 10% of it's weight.

Car 1 Transfer - 246 lbs.
Car 2 Transfer - 266 lbs.

Totals:

Car 1 - 246 + 664 = 910 lbs. ... 15% reserve of linear traction gain
Car 2 - 266 + 718 = 984 lbs. ... 9% reserve of linear traction gain

From that we can estimate a 6% decrease in ability under those conditions. That however is an evenly distributed shift such as what occurs under braking. When cornering the load of the car is pushed to the outer wheels in the same fashion but dependent upon a number of factors, can weigh more onto the loaded front tire due to deaccelleration transfer as well.

Running a higher spring rate is a compromising solution, because you then have to live with the downfalls of a higher spring rate. You also then have to revalve the shocks to incorporate a higher compression value as well as slightly increasing the rebound to promote shift when you make an input change (think inertia). You should also increase your front sway bar diameter slightly to incorporate this change.

Moving weight to the rear is an excellent idea, but it's not something that is RB specific. Things that would be RB specific in terms of overall weight benefit would be things like, removing the boat anchor exhaust manifold and replacing it, removing the big intake manifold from hell, etc. I wouldn't look too much into removing much more weight off the car itself... but at the source of the issue to begin with... the motor.

Will an RB powered 240 ever outhandle an equal SR powered 240? No, it's physically impossible.

Will an RB powered 240 ruin my ability to have fun around the corners? No...

Has an RB25 240/Skyline ever gone faster than 8.60 on a door slammer full chassis car? ... not that I am aware of (In accordance to your "power potential" remark )

 

Yep i do have to agree with you, stock for stock or equal amount of upgrades, the sr will outhandle the rb. I can't deny that. But you can't deny that the RB has much more potential.

Will an SR powered 240 ever outpower an equal RB powered 240? No, it's physically impossible. :heyhey

anyways, the point of the post is to lay out the facts, and hopefully dismiss the rumors of the RB 240 to be a bad handler. Bad handler compared to sr, YES. Bad handler in general, NO

-Bluefire

 

Will an SR powered 240 ever outpower an equal RB powered 240? No, it's physically impossible. :heyhey

Higher cylinder pressures = greater torque production and thermal efficiency.

Thus a stock S14 SR20DET with less cylinders can and will produce more torque with a given amount of airflow than a stock R32 RB20DET. Let's not also forget the added frictional losses the RB20DET has over the SR20DET engine.

Numbers:

RB20DET - 210 ps / 180 lb. ft. (derived from 25 kgf/m)
SR20DET - 220 ps / 203 lb. ft.

Next time be specific

Both engines are good... I wouldn't mind having a 2.4L RB engine following Tomei's old specs.

BTW, I understand your motive, and you can see I am supportive of your ideology in my post above.

 

this guy is smart. i belive blue fire was reffering to a 25 though. as far as handling goes...suppose car 2 had bigger tires.. say: 275/40/17 front and 285/35/17. i know thoes are some pretty big tires but the extra contact patch up front will reduce under steer. but as you were saying if the cars are identical minus the engine. then the SR will outhandle the RB