Zep's uprated 4.7 brake disc and pad combination

Bebs

Member
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3,359
Back in April of this year I finally decided it was time to change all 4 discs on my GT. It was an advisory when I purchased the car so I knew I would have to bite the bullet sooner or later.
The OEM brakes on a 4.7 (GT/QPV) have never been known for their awesome stopping power and a number of people agree they are somewhat lackluster, even when new. Furthermore, you will all be familiar with that terrible one inch pedal travel before anything happens, then a sharp bite. It has always been slightly tricky to moderate braking, particularly at lower speeds or coming to a standstill gently.

So rather than go OEM I decided to go for Zep's uprated option. OEM discs are costly and for the sake of some £500 more in total for all 4 discs & pads, it seemed silly not to upgrade to large diameter discs. I needed both front and rear and promptly put in the order with Zep.
Some weeks later I received a message they had arrived and that Zep would very kindly deliver them personally to Aldous @ AV Engineering as the car was due a service.
I did take a good look at them when I dropped the car off and was surprised of not only the sheer size of them but also how awesome they looked next to an OEM disc.
Here are the exact specs:

Front: 380 mm (up from 360 mm OEM) fully floating with a black anodized aluminium bell. Curved internal vanes for better cooling, curbed grooved surface treatment. Ferodo DS performance pads.
Rear: 342 mm (up from 330 mm OEM) fixed rather than floating but with the same black anodized aluminum bell, straight internal vanes, curbed grooved surface treatment. Ferodo DS performance pads.

Colleting the car after the service, the new discs immediately pop from behind those Neptune alloys - visually a huge difference which doesn't really show well on photos. Almost jewelry like.
The following week I set off on a trip to France and was able to bed the discs and pads in and get a feel for them over the next 2000 miles and 5 weeks away.
The difference compared to OEM is night and day. They inspire confidence, particularly coming down from high speeds. That feeling of not knowing if the car is actually going to be able to stop properly is totally gone.
They are very progressive, unlike OEM, and you feel them bite from the slightest press through to a full hard stop.
It is an absolute no brainer if you are about to change discs, for the slight change on top of OEM costs, you get seriously uprated braking power. Its an absolute winner. Bravo Zep.

Sadly, the one inch pedal travel before biting was still there - so on my return I had Aldous fit some braided brake hoses. This made a huge difference and I am glad to report that the pesky pedal travel is now reduced significantly and the brakes bite immediately and progressively with no hesitation. Even if you are not about to change discs & pads, have some braided hoses fitted, its a cheap upgrade and makes a big difference.

Lastly, Zep was an absolute gentleman to deal with from start to finish - I cannot recommend him and his uprated brakes highly enough.

Fronts (with 22 mm black spacers)

108604108605108606

Rears (with 25 mm black spacers)

108607108609
 

Bebs

Member
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3,359
Not dumb at all - I'm not actually sure about that. The calipers are moved outwards with a bracket to accommodate the larger diameter discs.
Zep?
 

CatmanV2

Member
Messages
48,793
Not dumb at all - I'm not actually sure about that. The calipers are moved outwards with a bracket to accommodate the larger diameter discs.
Zep?

They'd be anything : OEM, FD and so on. Just curious as I initially thought there were new calipers, but the question becomes moot when I look at the photos.

I guess my next question @Zep is if the pad area is the same, how come stopping power is improved? Angular velocity?

<digs hole>

C
 

Bebs

Member
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3,359
The standard calipers are retained. When I look at the pads in situ, they cover the entire surface of the disc..
 

GeoffCapes

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14,000
Playing devils advocate, could the major difference be that you had old knackered discs and pads and replacing them with new discs and pads would make an obvious difference?
Obviously again, braided brake hoses will always improve braking feel.

They do look good though. On my GTS the drilled discs always needed clearing after some heavy use. Although once cleared they were all good again.

Do you have any additional noise from the grooved discs? I've uprated the discs on a few cars I've owned and always found there to be a bit of groaning noise on use.
But not on uprated drilled discs.
 

Bebs

Member
Messages
3,359
Playing devils advocate, could the major difference be that you had old knackered discs and pads and replacing them with new discs and pads would make an obvious difference?
Obviously again, braided brake hoses will always improve braking feel.

They do look good though. On my GTS the drilled discs always needed clearing after some heavy use. Although once cleared they were all good again.

Do you have any additional noise from the grooved discs? I've uprated the discs on a few cars I've owned and always found there to be a bit of groaning noise on use.
But not on uprated drilled discs.
No the difference is too huge to be just old knackered brakes (they still had a bit of life left in them according to AV) They are not just a small improvement, it’s a different car altogether braking wise. You can literally feel the vastly improved stopping power. I can best describe it as a 1.6 four pot engine going uphill versus a 4 liter V8. There’s just far superior excess of power, less stressed doing the same job.
A few other people on here have done Zep’s front disc upgrade, I’m sure they’ll be along to chime in.
Cant say I have noticed any additional noise at all. The GT wheel arches are pretty noise insulated with that carpet type material anyhow so I’m not sure I’d notice.
 

GeoffCapes

Member
Messages
14,000
No the difference is too huge to be just old knackered brakes (they still had a bit of life left in them according to AV) They are not just a small improvement, it’s a different car altogether braking wise. You can literally feel the vastly improved stopping power. I can best describe it as a 1.6 four pot engine going uphill versus a 4 liter V8. There’s just far superior excess of power, less stressed doing the same job.
A few other people on here have done Zep’s front disc upgrade, I’m sure they’ll be along to chime in.
Cant say I have noticed any additional noise at all. The GT wheel arches are pretty noise insulated with that carpet type material anyhow so I’m not sure I’d notice.

Good to hear! :clapps:
 

mowlas

Member
Messages
1,733
@Bebs thank you for a comprehensive review, Brian!

I will need to change my front discs and pads soon. @Zep are able to recommend the specific versions of these for a 2007 QP Sport GT Auto? Also what are the best pads for these from a low noise and performance perspective?

Thank you!
 

Zep

Moderator
Messages
9,283
@Bebs thank you for a comprehensive review, Brian!

I will need to change my front discs and pads soon. @Zep are able to recommend the specific versions of these for a 2007 QP Sport GT Auto? Also what are the best pads for these from a low noise and performance perspective?

Thank you!

My understanding is that the 2007 Sport GT has the 330mm discs, is that correct? I can make some suggestions for 330mm discs, but the big brakes will not fit I am afraid*

*Unless you change the calipers.
 
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Devonboy

Member
Messages
1,291
Playing devils advocate, could the major difference be that you had old knackered discs and pads and replacing them with new discs and pads would make an obvious difference?
Obviously again, braided brake hoses will always improve braking feel.

They do look good though. On my GTS the drilled discs always needed clearing after some heavy use. Although once cleared they were all good again.

Do you have any additional noise from the grooved discs? I've uprated the discs on a few cars I've owned and always found there to be a bit of groaning noise on use.
But not on uprated drilled discs.

To give some colour on this point , I changed my healthy discs for Zeps fronts (had a special deal available from a @Gazcw who even fitted them) and can second everything Bebs has said. I am now going to look for some braided brake hoses!
 

Zep

Moderator
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9,283
Thanks @Bebs, it was great to deal with you too.

To answer some of the questions:

Pads: These are Ferodo DS Performance. These are still R90 compliant, but give slightly better performance than a standard pad.

Pad area: this is the same as standard, the spacer and exact disc diameter were the subject of a lot of study during the development and are specific to ensure the swept area of the disc is exact.

Why are they better: several reasons. 1. The leverage ratio is greater, the amount of pad pressure needed to give a given amount of retardation is lower 2. The pads are better than standard. 3. The discs have better cooling for more consistent temperature.

Just new, rather than better: The difference between even a new 360mm disc and a 380mm are marked. Due to the increased leverage ratio, we knew the braking would be better, but the surprise was how much the modulation and feel were improved.

A not on Braided Hoses - I can now supply these, they are circa £100.
 

Ebenezer

Member
Messages
4,501
When you say leverage, it means that you are apply pressure further away from the centre because the radius of the disc is bigger by 10mm?
Eb
 

linescanner

Member
Messages
299
I did mine beginning of the year. Am with @Bebs here, the difference is significant. Have not done braided hoses yet, but may well do soon. The discs look great and work even better.
 
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Zep

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Really appreciate all the positive feedback chaps. It was a lot of work, with some great support from other forum members, to develop both this kit and the Gransport 6 pot upgrade.

I’m very proud to read that everyone that has them has felt the benefit.

For anyone pondering an upgrade, I’ll have a set of 380mm discs on the shelf in a couple of weeks, just in time for Christmas.
 
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philw696

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25,470
Well Done Zep just shows Maserati what can be done by enthusiastic owners of the brand on a forum that has members around the World.
 
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