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stephenh

Ride Height

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stephenh

I've had my car on the ground (on its wheels and tyres!) for the last couple of days, temporarily, to tighten up the suspension nuts and bolts. I've done it with 5" approx. clearance under the front most chassis rail (not the round tube that the nose section sits on, the square section just behind that), and 6 1/4" under the rear chassis rail as per the build manual. I've assumed the latter is the square section chassis tube just behind the floor pan which the seats sit in, although the manual actually refers to the back of the floor pan. However, on my chassis the steel floor pan is lowered, and raked downwards towards the rear, so if I measured from that I'd have an enormous amount of rake. It would look like one of those American "funny car" dragsters. Surely I should be measuring from the chassis rail  and not the floor pan, despite what the manual says?

My doubt about all this is that using the measurements in the manual (and taking it from the chassis rails as above) I end up with the bracing hoop which protects the bell housing and back of the sump, only about 3.5" above ground level! It might be a bit more than that as it wasn't an accurate measure, but it is certainly less than 4".

Can this be correct? Or have I gone wrong somewhere? 

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Simon Marks - North Oxfordshire AO

Hi, Stephen,

                    It sounds like you have measured from the same points that I did - I ignored the lowered seat pans.  Just wait until the engine goes in and the sump hangs down another 1"+ below that!

 

I followed Westfield's lead and welded protection strips to the sump and am now looking round for a shallower, winged sump to bring the lowest point up to that bracing hoop.

 

Simon

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stephenh

Hi, Stephen,

                    It sounds like you have measured from the same points that I did - I ignored the lowered seat pans.  Just wait until the engine goes in and the sump hangs down another 1"+ below that!

 

I followed Westfield's lead and welded protection strips to the sump and am now looking round for a shallower, winged sump to bring the lowest point up to that bracing hoop.

 

Simon

Oh no! I'm glad you have told me that now, as I'm seeing Peter May later today, so I'll ask him if a shallower sump is available for the Midget engine.

I think I'll add a bit to the suggested heights front and rear, to get a more sensible ground clearance. It would be ok if I was building a competition car, 3 or 4" clearance would be fine, but for a fun road car it is silly in my opinion.

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garytipping

Hi Stephen,

Which tyres did you go for?

Gary

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stephenh

Hi Stephen,

Which tyres did you go for?

Gary

Hello Gary,

I would have liked to use a trackday type of tyre, but because of the nature of the bodywork on the XI you are severely restricted on tyre width. In the sizes which will fit, there are no trackday tyres available so far as my researches found, so you are restricted to using either classic reproduction sports tyres, or a normal road tyre. I was reluctant to go down the classic sport tyre route, so investigated which normal road tyre in the size I wanted was likely to be the softest rubber, and hit on Dunlop Street Response 2 tyres. 

The size I have chosen is 165/65x13". I think a lot of XI owners/builders go for 165/70x13" but I was prepared to sacrifice a bit on tyre wall compliance if it meant I could use marginally more lock without the tyre fouling on the bodywork, and I also hoped the slightly shallower tyre wall might marginally improve the grip of the tyre on dry roads. Just my instinct, and it's probably b******s!

edited to add: and these tyres are mounted on 5.5" rims.

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garytipping

Thanks Stephen, I have read good things about the Street Response 2. I'm using 4.5" steel rims so going 155 section. Just off to the garage to fit the offside front corner, After that I can get some tyres and it can go on it's wheels for the first time.

 

Cheers

 

Gary

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stephenh

Simon, you might find that shallow sumps for 1275 "A" series engines are harder to find than rocking horse poo.

I spoke to Peter May earlier this afternoon, and he tells me that he is not aware of anyone who makes such a thing. He once fabricated one as a "one off" for a Formula Junior A series engine, and it was not easy to do. It took him about 2 days, so it would cost an arm and a leg to get someone to do it for you. I suspect part of the problem is that there is never any need for such a thing in a Sprite or a Midget, and not many other cars use this engine. Also, the crank throw is quite long for the size of the engine, so only limited scope for shortening the sump anyway.

I've had a more accurate measure, and using the build manual set up measurements I've only got about 3.5" under the back of the lowered seat/floor pan, and about the same under the transmission/sump protection hoop, so I'm definitely going to raise the chassis at both ends. Instinct tells me to look for 4" min. clearance, so raise it by 1/2" at both ends, and when the build is complete, have the suspension set up with me in the car, to achieve 4" min clearance.

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John

Can you not dry sump an A series?

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stephenh

probably John, but not worth it for what I'm planning the car for.

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Simon Marks - North Oxfordshire AO

Hi, Stephen,

 

I saw an advert for an Eleven recently that said it was fitted with a "Swiftune" shallower sump.  I rang Swiftune (in Kent) and, whilst it is not a stock item, they are currently having a couple modified for Formula Junior engines.  Once they have come back from being welded up, Swiftune have undertaken to ring me with a price for one.  It sounds as if they would work on a sump if supplied with one.  I'll keep you posted. 

 

My car currently has 3.25" below the nose of the sump (and 3.5" below the bracing hoop as yours) - I was incorrect when I said it was 1" lower than the hoop (it's that sort of distance below the bell-housing).  Once I have finished all the post IVA jobs (including getting Protech shock absorbers on the car), I, too, will be trying a slight raise on the suspension when I corner weight the car.

 

Simon

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stephenh

Thanks Simon, do let me know how you get on with Swiftune, and you can tell them you have another customer for one if the price is reasonable.

As for Protechs, I've already got them on  my car! I did a deal with the factory, paid extra to have Protechs in place of the standard ones. ;)  ;)

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stephenh

Any news from Swiftune, Simon?

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Simon Marks - North Oxfordshire AO

Hi, Stephen,

                     Nothing yet, I am afraid.  I'm busy with the post IVA changes at the moment so will not be bothering to chase until all that is sorted.

 

I followed Westfield's lead and welded steel strips to my sump before the engine was built.  I used 3mm strip, both along the length and transverse at the ends to give it extra strength.  When the car was brake tested for IVA, it was sitting on this in the rollers with no ill effects!  I'd try this first and see how you get on.

 

Simon

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stephenh

Why do people recommend 13" rim wheels for XIs? Or do they?

My findings suggest 15" wheels would be a better bet, because the ground clearance wouldn't be quite such an issue. Admittedly, it might make the problem of having to limit the lock so much more of an issue because the wheel rim and therefor the tyre would be a bit closer to the bodywork. 

So what do other owners do, do the majority use 13" wheels, or 15" wheels?

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Simon Marks - North Oxfordshire AO

Hi, Stephen,

                     I considered 14" (MGB) or 15" wheels but discounted both as:

  • It would have meant a final drive change to keep the gear ratios sensible
  • I want to get as tight a steering lock as possible.  I already have one car with a poor steering lock (Renaultsport Clio V6) but that is miles better than the Westfield was when I first drove it.  I measured the turning circle of the Eleven as 18 metres (with the stop tubes at the length suggested by the factory).  The Clio is 13m and it becomes noticeable turning out of the drive and in car parks.  My daily drive VW Passat has a turning circle of 11.4m, my Lotus Sunbeam 9.6m and an original MG Midget 9.2m (which the Eleven will never achieve)!

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