We've made it in to Pitstop.................
 

David Cunnington has just sent me this response.........from Tampa

Mike
We leave Tampa tomorrow afternoon and via Philadelphia get into Manchester Sunday at 0845
.......then drive back home and get rid of the jet lag !

Whilst we've been away I've stayed current through the laptop and processed Pistop (Mike comment - is that a well oiled Pitstop! - his spelling not mine!) as well.
The mag, including your article and pics, has been proof read and the printers told to go ahead
with printing and distribution so you should have a copy soon !

Re my brakes, yes the pedal is hard and could do with a bit more movement and stopping power.
The car is R87 GDV, a standard Hunter, 2300 Ford dohc, 5 speed box etc. I have no idea of the
type of pedal box etc but we can talk when we are home again........if the cost is around £100
I may be very interested, assuming I have the ability to do the job, so please class me as a
"possible/probable" and I'll talk to you soon.

regards
DC



I'm pretty confident we can find a home for the remaining two servos. Alan Hogg has expressed a loose interest: Chris Cunliffe has an M50 Cabrio and certainly should be persuaded. Then there is Andrew Curtis near Crediton, with the Purple Sportster with an M50 who should be persuaded too.
Do we know who owns the blue M3 Sportster?

I'll be ordering another batch yet..............................?!

Mike

Blue M3 Sportster??

I don't recall seeing that one? Do you have a picture?

Marlin have a Red M3 Sportster for sale, so maybe we should ask Terry if she wants to buy one to upgrade it.
http://www.marlinsportscars.co.uk/forsale/

Peter

Maybe I have made a wrong assumption, but there is a pale metallic Blue BMW Sportster, which has a flat deep rear valence and the M3 exhaust, plus BMW binnacle, which I thought you have commented upon in the past. It usually goes to Stoneleigh each year
Isn't that an E36 M52 M3?
I can't find a photo quickly, and am being hassled out shopping.................

Mike

Ah yes, your right, I know the one. Can't think of the guys name right now but he only lives a few miles from Stoneliegh.

Apart from chatting to him at Stoneliegh, i'm not sure if I have any contact details.
I think this is the one.......

http://www.msportster.co.uk/kit-car-...allery/page-5/

...enjoy your shopping!

Mike

I will take the spare chrome unit with adapter and long clevis, firm confirmed order.

I have sent you a PM re payment.

John

Added John back to the list.

John

Thank you for stepping in for the 6th Chrome servo.
I intend to place the order on Monday, subject only to getting a Tech. Spec. sheet from MBM.
Who knows - we might all get an early Christmas present this year!
Mike

Servo Payment
 

Guys

Many thanks for the offers to send/transfer money.

I would prefer to take delivery of the servos, adaptors and clevis pins, to know the final costs before setting the final costs - you never know, they might end up being slightly less than you thought?

regards

Mike

Mike,

that is very good of you, just make sure that you are not exposed. I am sure all of us would be happy to pay a large "deposit" up front if necessary.

Thanks again to all those who have put so much work into this.

John

Payment
 

Mike, again many thanks for all the work,I also am very happy to forward a large deposit in advance, and will obviously await to see what way you wish to get payment.I am confident no one will let you down!

And so say all of us, thanks Mike

Adaptor Plate Thickness
 

Peter

This should please you relative to your comment above.

Whilst checking all the details prior to ordering the servos ("measure twice, order once"!) I have discovered the closed recess in the Dual servo is only 6mm deeper than the projection from my master cylinder.Thus with a 6mm adaptor the two faces are flush (or may be just touching)
My Ford master cylinder has a 22mm projection: the servo recess is 16mm.
I am therefore going to increase the standard adaptor plate to 8mm thick to eliminate any possible interference issues with the standard Ford master cylinder I have.

If anyone has a problem due their master cylinder having a longer projection, I can get a marginally thicker adaptor (within reason, say 10mm or even 12mm), but please do check for yourselves the projection depth of your master cylinder from it fixing face.

Mike

Servo "Samples" Ordered
 

Quick update:

I have checked with MBM that their Dual booster is identical to the one we have tried as a prototype, and as far as we can tell it appears to be good news. (I know the Yanks are supposed to speak the same language, but they don't!)

MBM have agreed to accept an initial order for 2 off Black Powder coated servos on the pretext that they are "samples" to make doubly sure there will be no problems with the main order. The main order will then follow on immediately provided there are no surprises.
Hence my wink to Stuart and John last week.

MBM advise they will be despatched today, and therefore I hope to see them sometime next week.

Once received and (hopefully) approved, I will then order the balance of 6 chrome and 12 zinc boosters for delivery the week after............and you should all get them in time for Christmas.

Keep your fingers crossed.
Mike

Good news and great effort!

My wife was wondering what to buy me for Christmas lol...

Robin

Mike. All noted re 8mm plate which is ok by me :-)

P.S. Did you receive my PM sent a couple of days ago re payment? First PM that I have sent so not sure if it went ok. Peter.

Hi Peter

I have sent a PM reply for you to check out.

Mike

I've not had a PM but let me know whenever :) I have a BMW master cylinder with the offset adapter to fit on the metro servo.

Hi Patrick

I do not want any money until we prove the samples are correct.
After that I am happy to wait untill I know the final costs before advising anyone.

I think it is likely you will need a new adaptor plate as the Dual booster (those Yanks have got me using their lingo!) has two fixing posts 3 3/8" apart (more Yank speak) = 86mm centres.

Also can you check the projection of your master cylinder into the Metro servo, please?
The MBM Dual has a closed recess which is approximately 16mm deep, and may be too shallow for your master cylinder even with a 6mm adaptor plate.
I will get 8mm adaptor plates for those with Ford type master cylinders, but would like to be reassured these will fit the BMW master cylinders.

Thanks for your input .
Mike

Mike

Like Patrick I have the BMW E30 master + adapter plate + metro servo. The projection on the master is 18mm so from your figures we should be OK with anything over 2mm. Therefore 6mm would seem to be ideal but I am happy with whatever comes.

Sorton

Sorton

Thank you for that information - it is very useful. It means I can go ahead with a universal thickness of 8mm, knowing they will fit the Ford or BMW master cylinders............and they will be a little more robust.

Thanks again
Mike

Follow Servo Delivery progress
 

MBM have used USPS to send the first two powder coated servo samples, as the UPS cost for this small package was horrendous.

(Stuart and John can follow progress on the USPS website: using the code I have sent PM - they have reached New York as of this morning)

Always looking to keep costs down, I have promissed to delivery some of the servos whilst out on my work/leisure travels.

May I ask you all to forward your addresses via PM, and I'll see if there are any others I can add to the list, or maybe double up by getting one of you in a group to take delivery, and arrange local dispersal.

As for cost, Thank you all, I would rather sort the cost out when I know the final total costs and can be fair to everyone.

Goo

can you PM me Ian's contact details please?

Mike

Another Order
 

Jason

Can you add Andrew Curtis (BMW M50 Sporster) to the list for a complete zinc kit, please? Thank you to Peter V8 for putting him in touch.

By my reckoning we now have firm orders for 18 including myself, as I have someone willing to buy my original zinc servo which Jason tested (not shown on Jason's list).

That potentially leaves only two unallocated zinc units at present. So if you know anyone who is interested they need to get their order in quickly!

No probs Jason. Mike. Please also see my PM about Andrew Curtis re further contact info re the servo “kit”. Many thanks. Peter

No PM

Mike

Servo
 

hi mike, did you get my details on pm I sent? Jeremy

Follow Servo Delivery progress
 

The two sample servos have landed in UK this morning.

C'mon!

Hi Mike

PM sent with details

Sorton

Mike. Just replied to your last PM. You have correct email for Andrew C. Peter.

Techy Figures
 

MBM have sent me an article about the effects of a brake booster - christ I'm even talking like one now. Y'all hear!

Does anyone know how to post a pdf file, or copy of one on to here?

It has prompted my old grey matter in to action again, and I would like others thoughts too.

Not sure, but I think you'll have to ask one of the guys with 'real websites' to host the document. Jason, Robin or Patrick should be able to help?

Depending on how large it is, you should be able to attach it to the post. Max file size is 19.5K though.

If it's that size or under, just use the paperclip button in the post toolbar to attach the file.

I'll host it if neccessary...

I've managed to OCR the Doc that Mike sent me, and shrunk it down enough to attach here. I'll also put the original on my site and post a link later on when I get in from work.

Guys

I don't know if any of you looked at the specification figures for the boosters, or are even interested in the numbers, but I have made some calculations based on the data given by MBM, which show a very interesting result: see if you agree with the following;

My brake details are:
Pedal centre to pivot centre 32cm - excuse mixed units - it does not matter
Pedal connection to servo to pivot - 8cm
Therefore my pedal ratio is only 4:1
My master cylinder bore = 22mm = 7/8" = 0.6 sq inch
Now assume 23” of vacuum and 100lbs of applied foot pressure for comparative purposes.

Based on my brake's details:
[edit: it will not hold spaces to make figure line up below]

Booster size “Manual Pressure” “Free Pressure” Total Brake Pressure
7” Metro 666 psi *1 587 psi *2 1253 psi
7” Dual 666 psi 815 psi *3 1481 psi *4

*1 = (100lbs x 4:1) / 0.6sq.inch = 666psi
*2 = Metro booster constant 352lbs / 0.6 = 587psi
*3 = Dual booster constant 490lbs / 0.6 = 815psi
*4 - The dual offers an increase of 18% of the total over the Metro. This does not sound too impressive.

I then considered if I reduce the distance of myservo connection to pivot by 1.6cm to 6.4cm

The new figures are:
New pedal ratio is 32/6.4 = 5:1
Same master cylinder bore = 22mm = 7/8" = 0.6 sq inch
Same 23” of vacuum and 100lbs of applied foot pressure.

Proposed brake's details:
Booster size “Manual Pressure” “Free Pressure” Total Brake Pressure
7” Metro 833 psi *1 587 psi *2 1420 psi
7” Dual 833 psi 815 psi *3 1648 psi *4

*1 = (100 x 5:1) / 0.6 = 833psi
*2 = Metro booster constant 352lbs / 0.6 = 587psi
*3 = Dual booster constant 490lbs / 0.6 = 815psi
*4 - The dual offers an increase of 16% of the total over the Metro, appears not so good

However, if we turn the calculation around to how much foot pressure is required to achieve the same total as with the original Metro, we see a significantly different result:

Original foot pressure to achieve 1253psi was = 100lbs
New foot pressure to achieve 1253psi = 52.4lbs *5

*5 = 52.4lbs x 5:1= 262lbs / 0.6sq.in = 438psi + 815psi = 1253psi
ie almost only HALF the effort

This has got to be worth a try!!

What master cylinder bores do you have?
What brake pedal ratio do you have?

Does anyone have a view on the calculations?

Reply from Marlin Cars
 

I've had a response from Terry at Marlin today ref adopting the Dual servo for future cars:

[Hi Mike
Mark has now read your email with interest and of course yes he would like to have a look at what you have found. A few points that may bear thinking about
1) That with your new servo installed and the mechanical advantage that it gives you may, on the one hand make you feel comfortable about the fact that less (personal)pedal pressure needs to be applied to cause the front wheels to lock ............ this situation is not necessarily going to result in a more safe brake situation.

2) With reference to the new servo & brake pedal pressure it is an IVA requirement that the brakes must operate correctly and effectively at 400 nm of pedal pressure. This stipulation would allow for a test range of 0-400 nm’s, if the wheels lock and say 200 nm’s you will only be left with half the range of brake application/feel.

3) In your pictures it didn’t look as if you had a very good vacuum seal face between servo and master cylinder. Maybe its not the case it just looked that way from the pictures.

4) £100 for a servo seems like a very reasonable price... if not a good one.

5) Mark was not sure from your email of exactly the situation i.e. are you having these servo’s manufactured for you and have you then ordered some stock or are you simply buying them through an EBay shop (or were you trying to say that the EBay source is you)?

In closing Mark would be very interested to take a close look at these servo’s and if you would like to send one we will be happy to pay the £100 cost and postage of course
ATB
Terry.]

I have replied that we currently plan to have two spare servos on order and that they are welcome to one of them for trialling.

It will be very interesting to see what price they want to charge for the kit?!

Servo Testers Wanted!
 

How many owners have registered cars that they will be running through the winter?

We will need you to give us all more feedback on the new servo!

Mark must be really interested if they are prepared to pay for one and do some tests. ("Delivery will be in about 6 weeks...." :eusa_whistle:) :wink:

Mike likes that..................:heh: :heh:

Update list
 

Jason

Is your PM working?

Can you add:
Andrew Curtis & now Marlin to the list.
I believe this only leaves one servo from the 12 zinc units unallocated.

They're going quickly............................