Cracks

[Guest alexpink]

So after 1150 miles I've managed to get some of the infamous S7 cracks at the back of the engine bay area... Going to drill a hole, get it welded, and get some angle on there to strengthen it. Is there anything else that needs doing or should this suffice?

[Longboarder]

Strange how some crack and some don't. Mines got 27000 on it and no cracks. Spring rates and damper quality must play some part in cushioning the stress points. What model is it (to give clear indication of the suspension style) and what are the current spring rates?

 

Nigel

[Guest alexpink]

Mild steel mono, inboard coilovers-mk2 S7 I think.

Spring rates are standard I guess but are way too high and will hopefully be one of the changes I make over winter.

[cb750]

On the Sierra based cars, I believe the original Sierra anti roll bar if used was the main cause as its too strong for our cars and puts stress back onto the chassis

[Guest alexpink]

I have tie bars. I'm surprised that the cracks have occurred this soon but the chassis is from 1995 so I guess age may be the defining factor alongside mileage.

[Guest 2b cruising]

Your tie bar transmits a heck of a lot of vibration to the chassis.

Every nick, lump, bump and stone is felt where it mount to the cassis.

Some people have put strengthening bars from one mount to the other side.

[Guest mower man]

I HAVE BEEN SAYING ALL THIS FOR YEARS AND DAVE ANDREWS BEFORE ME !! the tie bars do not crack the chassis the insane spring rate originally put on by tricky dicky and use of the massively over rated anti roll bar are the prime suspects for this . my stainless mono car developed 2 small cracks in the so called usual areas which various methods were used to cure ranging from new bulk head and floor ,extra chassis members in tube, angle iron,1/8" sheet steel ,ply wood you name it ! I simply drilled the end of the crack and fitted a 3/8 dia bolt with 2"repair washers and cranked them up tight, fitted tie bars finally with poly bushes and lowered spring rates from the 180 stds to 120 It ran it like that for 10+ years and as far as I know it is still the same [ I sold the car last year and presume that its still ok !!] A roll bar could still be used ,but would need to be only 30% as stiff as the original . this is not a fairy tale but the truth if any one would like details of the mod as I did it please get in touch mick

[Guest Bobbers]

I've ragged the above car round for the last year doing a few thousand miles and had a good look for cracks while I was do the mot and I can happily report its all good !

[Peter Bell]

I'm suprised it has happened so early on a mild steel one though.

[Guest alexpink]

Mick- do you know where I can get some springs with a lower rate? I would imagine mine are standard as they are extremely hard, it understeer quite badly, and there is barely any travel in the suspension. This was something I wanted to get sorted soon but its evident that changes are needed imminently.

Also developed some gearbox issues (probably bearing related unfortunately) so I will be busy over winter. Going to try and make it to the midlands meet on Wednesday as my last run out this year.

[cb750]

I'm pretty sure I got mine from Rally Design. Just need diameter, length and spring rate required.

[Longboarder]

Dave Andrews for those who don't know/remember was a RH guru who moved on to tuning/development of the K series engine for the Caterham boys and is now highly respected in that field and others. His website has been up for 20 years http://www.dvandrews.co.uk/

It still has all the original problem sorting articles he wrote for early hoodies and they are all worth downloading and saving for reference.

 

Nigel

[Guest mower man]

Mick- do you know where I can get some springs with a lower rate? I would imagine mine are standard as they are extremely hard, it understeer quite badly, and there is barely any travel in the suspension. This was something I wanted to get sorted soon but its evident that changes are needed imminently.

Also developed some gearbox issues (probably bearing related unfortunately) so I will be busy over winter. Going to try and make it to the midlands meet on Wednesday as my last run out this year.

There are a number of suppliers around ,basicaly cos they are on my door step I used damper tech .If I remember correctly [ not allways ] I got some 11" 120 lb springs from them and unless Bobbers has changed them thats what its on now , have a word with Dave at DAmpertech he might have records mick

[Guest alexpink]

Thanks for that Mick, I'll look into it.

 

Nigel, I've used Dave's site many times... Just completely forgot about the section on reinforcing and suspension lol. Thanks for the reminder.

Edited October 25, 2015 by alexpink

[Snapperpaul]

mine cracked under the boot floor diff area

 

 

 

Edited October 25, 2015 by Snapperpaul