Uprate A Diff?

[opalfruits]

If I wanted to run a bit more power through the rear diff on my coupe is there a firm that will uprate it? I have had a thread up before regarding this subject and someone mentioned that it would take 200ish but I need to run about 300bhp so want to make sure its strong enough to take it. Any help would be great. Thanks

[lamchop77]

300 bhp!!!!! sounds like a SAAB turbo motor. I'm not aware of anyone that can uprate the diff other than ZF, quaife, possibly Tran-x. The problems that i,ve heard of /come across are usually to do with the torque tubes and bearing failures.

I have a ZF diff but managed to wreck that with 160bhp so personally i think the manta diff isn't up to the task. Blew the gears to pieces inside it(well i'm pretty sure thats what all the bits of metal are!!!!!!) I did use a std manta axle with theplanet gears welded up and the rest of the axle was ok with 180bhp (ish) running through it for a while until i changed it for a better rear end on the grasser.

Look at ford Atlas axles (could cost alot even 2nd hand), Hercules axles at Rally Designor possibly the volvo or BMW route. BMW route is full independant rear but you'll probably have to do a fair amount of alterations/fabrication to get it in, but if you find a 328 rear end it will probably have the lsd as std. Sierra fits, got that on the grasser, but again your cutting floorpans /sills etc.

Personally in would go the Ford route, there stuff always seems stronger as std and all the performance bits are cheaper aswell.

HTH

Chris

[opalfruits]

300 bhp!!!!! sounds like a SAAB turbo motor. I'm not aware of anyone that can uprate the diff other than ZF, quaife, possibly Tran-x. The problems that i,ve heard of /come across are usually to do with the torque tubes and bearing failures.

I have a ZF diff but managed to wreck that with 160bhp so personally i think the manta diff isn't up to the task. Blew the gears to pieces inside it(well i'm pretty sure thats what all the bits of metal are!!!!!!) I did use a std manta axle with theplanet gears welded up and the rest of the axle was ok with 180bhp (ish) running through it for a while until i changed it for a better rear end on the grasser.

Look at ford Atlas axles (could cost alot even 2nd hand), Hercules axles at Rally Designor possibly the volvo or BMW route. BMW route is full independant rear but you'll probably have to do a fair amount of alterations/fabrication to get it in, but if you find a 328 rear end it will probably have the lsd as std. Sierra fits, got that on the grasser, but again your cutting floorpans /sills etc.

Personally in would go the Ford route, there stuff always seems stronger as std and all the performance bits are cheaper aswell.

HTH

Chris

Thanks for that Chris. Just sent an email to a company called Gartrac who provide Atlas axles so I will see what comes of that.BTW its not a Saab engine

[opalfruits]

Quick update. I emailed the company as mentioned above but had no response . I have been in touch with Quaife but all they do is replace the diff innerds which doesnt really help as its the torque tubes that tend to give first. What I need is someone to build a rear axle and diff to the Manta spec just stronger (thats all he says!!) I have scoured the net looking for such a firm but to no avail. Does anyone know of anyone that will do it?

[simon p]

Quick update. I emailed the company as mentioned above but had no response . I have been in touch with Quaife but all they do is replace the diff innerds wich doesnt really help as its the torque tubes that tend to give first. What I need is someone to build a rear axle and diff to the Manta spec just sronger (thats all he says!!) I have scoured the net looking for such a firm but to no avail. Does anyone know of anyone that will do it?

I'm on it already, had a chat with Robbie a few months ago and he thought it was a good idea too. what torque are you expecting

[opalfruits]

I'm on it already, had a chat with Robbie a few months ago and he thought it was a good idea too. what torque are you expecting

Thought what was a good idea? Did I miss something

[Robbie]

Getting uprated manta rear axles build to handle the type of power and torque owners are now putting into the cars , no need for the

[opalfruits]

Getting uprated manta rear axles build to handle the type of power and torque owners are now putting into the cars , no need for the

so was there an outcome of the idea? I may well have to use other methods if this is a sketchy subject.I thought that there were people out there that did this sort of thing but maybe I was wrong. I will speak to my local engeneers and see if they can suggest anything.

[simon p]

if this is a sketchy subject................... anyway.................

Sorry, didn't explain my point very well. I'm currently designing a direct replacement rear axle but able to handle more torque. The reason, i'm doing a lot of V8 conversions now and need to offer an axle to handle them, i'll hopefully be able to offer them with various ratios. The other reason is i'm scared silly by the impending modified vehicle rules.

[mantaray]

The other reason is i'm scared silly by the impending modified vehicle rules.

What rules are these,Simon?

[simon p]

What rules are these,Simon?

Hi Chris how you doing? good i trust.

There's a lot more info here http://www.the-ace.org.uk/

This is taken from the DVLA website

The vehicle must score eight or more points to retain the original registration mark. If less than eight points are scored or a second-hand or modified chassis or altered monocoque bodyshell is used an Individual Vehicle Approval (IVA), enhanced single vehicle approval (ESVA), single vehicle approval (SVA) or motorcycle single vehicle approval (MSVA) certificate will be required to register the vehicle. A 'Q' prefix registration number will be allocated.

Basically, if your car fails to score enough points to keep it's main identity, it could very well have to be subject to the new IVA test.

The following values will be allocated to the major components used:

chassis or body shell (body and chassis as one unit - monocoque ie direct replacement from the manufacturer) (original or new) = 5 points

suspension = 2 points

axles = 2 points

transmission = 2 points

steering assembly = 2 points

engine = 1 point

Where there is evidence that two vehicles have been welded together to form one (ie 'cut and shut') a 'Q' mark will be allocated, IVA, ESVA, SVA or MSVA will be required

This isn't a new thing but is being policed more and more. I have heard from a good source that DVLA inspectors are touring car shows and taking down number plates of cars they feel could fall foul of these rules and calling them in for inspection. These rules could be applied to cars built several years ago.

So being able to retain a stock fitment axle is of HUGE advantage.

[opalfruits]

Hi Chris how you doing? good i trust.

There's a lot more info here http://www.the-ace.org.uk/

This is taken from the DVLA website

The vehicle must score eight or more points to retain the original registration mark. If less than eight points are scored or a second-hand or modified chassis or altered monocoque bodyshell is used an Individual Vehicle Approval (IVA), enhanced single vehicle approval (ESVA), single vehicle approval (SVA) or motorcycle single vehicle approval (MSVA) certificate will be required to register the vehicle. A 'Q' prefix registration number will be allocated.

Basically, if your car fails to score enough points to keep it's main identity, it could very well have to be subject to the new IVA test.

The following values will be allocated to the major components used:

chassis or body shell (body and chassis as one unit - monocoque ie direct replacement from the manufacturer) (original or new) = 5 points

suspension = 2 points

axles = 2 points

transmission = 2 points

steering assembly = 2 points

engine = 1 point

Where there is evidence that two vehicles have been welded together to form one (ie 'cut and shut') a 'Q' mark will be allocated, IVA, ESVA, SVA or MSVA will be required

This isn't a new thing but is being policed more and more. I have heard from a good source that DVLA inspectors are touring car shows and taking down number plates of cars they feel could fall foul of these rules and calling them in for inspection. These rules could be applied to cars built several years ago.

So being able to retain a stock fitment axle is of HUGE advantage.

Pull your finger out then cos I need one .In all fairness I think I will have to use the donor rear beam, didnt want to do that cos of all the work involved but needs as needs must...