Rear springs

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Rear springs

Postby JDaly » Fri Nov 24, 2017 1:09 pm

Hi,
I have Gaz coil-overs front and rear, with MX5 independent wishbone arms at the rear.
I was advised to go for 120 lb 12" springs for the rear, but these have proved too soft - the arse end bottoms out on bumps, especially with two people in the car.

The guy at Chamberlains (automotive spring expert here in chch) suggested 175-200 lb was the norm for the rear, but the Gaz guy I spoke to insists on 120 lb as being normal saying 175-200 would be way too firm.

Any guidance on rating for rear springs?

My car might be a different to the traditional lotus 7 set up, having wishbones at the rear, and no torsion bars. The gaz coil-overs are doing all the work.
I only have 150 lb springs at the front, and they seem fine.

So, interested to hear what others have used and your experience with trying different rated springs.

Thanks,
Jason
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Re: Rear springs

Postby feckn7 » Fri Nov 24, 2017 5:22 pm

I used what caterham use 150lb on rear
Gives a nice ride and has never bottomed out even with 2 up

David
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Re: Rear springs

Postby SR Components » Fri Nov 24, 2017 6:07 pm

225
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Re: Rear springs

Postby davew » Fri Nov 24, 2017 11:49 pm

For "road" use a rear spring rate would typically be in the range of 150 to 170 lbs. I ran 150 for a long time but would occasionlly bottom out. Now at 160. Dave W
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Re: Rear springs

Postby nz_climber » Sat Nov 25, 2017 8:55 pm

I suspect you will get every answer between 100 and 300 as what works on one car might not work on another.

It depends on your ride height, shock angle, mounting distance from shock to wheel center line. Available compression, even the spring itself and lots of other things to!

How much compression do you have available on the back? Was the ride height set with at someone in the driver's seat? Is it hitting the bump stops or coil binding or something else running out of travel?

I run 200lb in the rear of my irs McGregor. 175lb felt good too but due to spring length it would coil bind before hitting the bump stops.

Front and rear do sound a bit soft overall but some cars are like that. Also remember changing just rear springs will change the balance of the car on the limit too which might be good or bad depending what it does.

Sent from my Nexus 5X using Tapatalk
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Re: Rear springs

Postby JDaly » Mon Nov 27, 2017 7:25 am

Thanks everyone, for your time and useful answers.
It is what I thought - 120 is too soft.

I'm going to order some 175 lb springs and see how they work out.

Sounds like I might need to keep an eye out for some higher rated springs for the front, too...
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Re: Rear springs

Postby SR Components » Mon Nov 27, 2017 8:27 pm

Its a balance , be carefull.
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Re: Rear springs

Postby bzrse7en » Wed Nov 29, 2017 1:25 pm

Pretty sure on gaz website they recomended 180 on the rear and 220 front of a westfield , that is what I used . The locost is basicly a westfield copy.
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Re: Rear springs

Postby silvo » Thu Nov 30, 2017 9:47 am

Just wondered who is a good supplier for springs ? - cheers Neil
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Re: Rear springs

Postby 7ish » Thu Dec 07, 2017 3:18 pm

I get mine from demon tweeks... about $100 landed, takes 7 days.
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