Identifying shocks and ride height

[Philk]

Given different spring rates, tyre heights etc, the following diagram from the original 1961 brochure may assist:



NB all dimensions were shown for a laden car (not sure what is meant by laden - Driver and Passenger & full fuel tank?)

The Front (16.75 inches) / Rear Bumper height (21.5 inches) are of particular note as is the ground clearance expected under the mid-point silencer (5.5 inches) What is of interest (given this thread) is that a laden car would have the rear wheel arch aligned with the wheel rim.

[mgcjag]

Hi Phil.....front/rear bumper height is different in the diagram....not the same.....Steve

[dlgis]

I definitely don’t have 5.5” ground clearance but that could be down to the way the exhaust has been fitted. I will have a look at overall height (when I’m back in UK) as this could be a useful indicator.

[Philk]

Hi Phil.....front/rear bumper height is different in the diagram....not the same.....Steve

Yes, I spotted that too but only after my original post (I've now updated that). The photo below (from the Technical Descriptions and Specifications booklet) clearly highlights the degree of difference



If the ride height figures were supposed to be with the car laden, it makes you wonder if there were weights present in the boot of the car when the photos were taken thereby forcing the rear wheel rims to be level with the wheel arch (as per the sales brochure dimensions diagram above).

[TGN]

Has anyone here actually used these springs
https://britishclassiccarparts.com/coll ... r-coil-set

I’m going to need to replace my springs shortly as the car is too low.

[Maikel]

Right time to join the topic,

I also have the same GAZ newly installed. With standard tires and 15" wheel the top of the rim measured from ground level is 53 cm, the wheel arcs measure 55.5 from the ground.
So it is about 2.5 cm gap. Equal on both sides






At the front I have 22.5 cm as measured and indicated at the workshop manual



Still it appears rhe car is sitting slightly low at the rear.
I do not want to lower at the front as the exhaust clearance is already just below 5". Might be an issue of the exhaust.

Who can confirm either of the measurements?

[dlgis]

Hi Maikel that’s helpful information. I’ve just checked the measurements on my car against yours. Your figures in brackets:

Rear wheel - ground to top of rim 52cm (52.5-53)
Ground to top rear wheel arch 52.5cm (55)
Front - ground to torsion bar centre 19cm (22.5)
Ground to bottom of IRS carrier 17.2cm - thats about 6.75” and i believe i read somewhere it should be over 8”.

I’m thinking my ride height is about 3-4cms too low. I’m wondering whether Gaz do a longer spring length for their adjustable fixed platform shocks. I’ll give them a call.

[mgcjag]

Hi Darryl/Maikel.....there is no rear ride height spec in the service manual for S1-S2 cars.........the S3 manual gives a drawing and measurement from bottom of irs plate to ground on 7.9in +- 0.25in........i tried to get members to measure their rear ride height a while back.......iv also measured quite a few myself..obviously tyres will differ but across the S1/2 cars the measurements that gave a correct looking ride hight in my opinion was 7.25- 7.5in from lowest lip of irs base plate to ground....you can raise yours with spacers available from usual suppliers......lowering is obviously more difficult.......Steve

[Maikel]

Hi Darryl,

so your rear seems to be about 1 cm lower than my what could be a tire issue. I have the Michelin 185x15 and 2 bar pressure.

But also the gap between your rim and wheel arch is too small according to me.

What surprises me even more.
You say, the center of your torsion bar is 19 cm from ground, which seems to bee extremely low.
The 22.5 cm on my car are measured from the center of the lower wishbone shaft according to the picture , the torsion bar should be just a bit above.

Having said that, you would have to raise your front even more which would just be the opposite of what you are after.

It seems, you really need to get other rear coils, but your front is too low as well.

I have done 2 miles in my car and I am a bit reluctant to lower the front on my car as it might still drop a little bit due to the new bushes at the front suspension. So maybe some railway's or curves will drop it.

I might wait with lifting the rear end on my car.

Keep me tuned.

Maikel

[Maikel]

Just measured,

my lower lip at the IRS plate is 6.75" from ground. So I could do with some spacer or other springs as well?

[mgcjag]

Hi Maikel......what car model are you measureing.......the diagram above for the front ride height is from the 3.8 section of the service manual........there are other measurements for later models....in the service manual...Steve

[Maikel]

I took the picture of a later green workshop manual, I also found another drawing where you had to deduct height B from Height A and it was as gap of 16 mm +/- something, but that was in an earlier workshop manual.

So, you are saying there are 3 different heights or ways to measure the torsion bar adjustment?

I was also wondering,

When you mount higher springs or install spacers, do you get more ground clearance between IRS cover plate, do you increase the gap between rim and wheel arch or both?

[mgcjag]

Hi Maikel......no not 3 different ways to measure the height. .......there are different heights for different models....there are setting links used to set front ride height.....different setting link dimensions for different models........Re the rear....when you add spacers or fit taller/ stiffer springs you raise the irs/body.....so you get more ground clearance and more gap between rim and wheel arch.....Steve

[dlgis]

Maikel, did you buy new springs from Gaz with the Gaz dampers? If so do you have details of their specification?
Thanks
Darryl

[Maikel]

@Steve
I am aware that early, later and 2+2 do all have a different front torsion bar setting tool. They vary slightly. But I also know that when using this setting tool it does not mean your front ride height will stay correct.
I had that with one of my cars, but worn torsion bars resulted in a dropping front height.
So even using the correct setting tool we all know that the below distance is not always correct.







So, what are we after? The setting tool distance or the exact ride height at the front?

However
I do have 22.5 cm at the center of the lower wishbone shaft which is in the tolerance of 22.2 +/- 0.64 cm.

And here are pics of my delivery from SNG
I have been told I would not need any spacer.
Just the springs and dampers.

I think now I still need those spacers or longer springs.







Maybe spring C18977 is to short, or even wrong.

I have some 11 mm spacers which I will now install and that might help to get more ground clearance at the IRS plate and balance the car front-rear height.

[abowie]

I have some 11 mm spacers which I will now install and that might help to get more ground clearance at the IRS plate and balance the car front-rear height.

What's important about ride height is that the exhaust doesn't hit the ground when you go over a bump. Those spacers should give you around an extra inch at the rear.

As an aside if you look at the SNGB website (as an example, not being critical) they list C18977 as the same part as C25939 and say that it's suitable for all of the cars below, even though they have different part numbers.

• E-Type S1 3.8 DHC
  
  E-Type S1 3.8 FHC
  
  E-Type S1 4.2 2+2
  
  E-Type S1 4.2 DHC
  
  E-Type S1 4.2 FHC
  
  E-Type S1.5 2+2
  
  E-Type S1.5 DHC
  
  E-Type S1.5 FHC
  
  E-Type S2 2+2
  
  E-Type S2 DHC
  
  E-Type S2 FHC

They're now also offering a GAZ uprated rear spring too.

[mgcjag]

The problem we have here is that both Maikel and Darryl are useing aftermarket shocks and springs.....so we wont know whats causing the problem....shocks, springs, or both....the Gaz shock has a fixed lower platform as far as i can see there the originals diddnt........first step would be to to compare the spring pearch distance...if its the same as originals then you can point to the spring.......if you want to know whats wrong then you need to start measureing....not the ride height but tne shocks.....Steve

[dlgis]

I’m hoping to get the car up on my mate’s ramp in the next couple of weeks, then we’ll be able to get a shock off and see what I’ve got. I think it’s most likely i have the Gaz 8” springs. The springs look nearly new and i reckon the previous owner will probably have fitted them as a complete set of Gaz springs and shocks.

[Maikel]

Today I was driving some railways, and the fro t dropped about 1 cm, hope it does not drop any further. As the exhaust is low already.

But I will not do anything at the rear suspension at the moment.






It has now just 3.5 miles and still need driving in.

[dlgis]

I just had a chat with SNGB. They say the standard springs C25939 will fit the adjustable Gaz dampers (fixed platform) and that they are 11” (28cm) long and have a spring rate of 270lbs.
The Gaz springs sold by SNGB come in 2 flavours, 275 and 325lbs, and are both 8”.
If i have the Gaz 8” 275lbs springs ( i need to check this) and i replaced them with the standard 11” 270lbs springs would the approx increase in ride height be 1.5” ?