Hey guys i have been looking into trying to work out what spring rate to use on my 1600. I have had a look on here and online but i havent found much i understand . I will be running a sr20det and will be a street/daily driver (i hope anyway).If i run 200lb springs on the front will i need to run 200lb on the rear?

Cheers,

Richard.

There is good info on front and rear spring rates on this forum. Try other search words.

If your seeking info on Datsuns with IRS, rear springs need to be much higher poundage per inch, as they are not direct acting like a front strut. 740 lbs per inch for rear rings a bell, but check this out in the forum files. I just searched by "spring rates" and found 118 pages referred. Should be some useful info in there!

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RichardC
SSS016

motion ratio is roughly 4:1 on the rear so your rear springs will need to be about 4 times the rate of the fronts

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1971 Datsun P510 SR20DET 276 rwkW
2005 Mercedes AMG E55 350 kW
1969 Datsun P510 L20B EFI 95 rwkW
1975 Ford XB Fairmont GS Wagon 179rwhp
1980 Escort Van SR20DET unfinished
2002 Suzuki GSX1300R Hayabusa 185hp

Ive not heard of that rule of thumb before - match front and rear spring rates, generally because of the CoG location in the car you don't need the rear as stiff. But if it works for 1600 that's pretty convenient.

Agreed with the installation ratio though (If the ratio is correct) but not that the front needs to match the rears.

Usually, from my knowledge more race orientated, you determine your front and rear ride rates and match springs to those requirement, and then do the same for front/rear roll rates and choose a anti-roll bar to make up the delta.
Given this is a standard conversion, with standard suspension geometry there is no point going through all the calcs.
Either take forum advice or Ring Datsport to get the ideal road rates, they should have done the hard work for you and testing. Then of course, ethically, throw them some business to support the small dedicated community.

Bryan