SM Big Brake Kit - QP V Sport GT S

MikeyMaser

Junior Member
Messages
229
Having installed the SM (not big, but standard 360mm on the front) kit on my Sport GTS, I concur with everything @Devonboy says. Pedal feel is still fairly long compared to some cars but the initial bite and confidence in the brakes is much improved.
 
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Devonboy

Member
Messages
1,054
This is where it all gets a bit interesting. If you don’t change the master cylinder, you have to keep the same piston area in the caliper, or you have an issue with pedal travel, so the only benefit from a 8 pot caliper is increased pad area, not really something there is a massive issue with. To me, the difference to a German is pedal pressure, there is more servo assistance which gives the feel of more initial bite.

Almost anything is possible, 380mm is the limit for the standard caliper in terms of adaption, but with a different caliper 400mm would be possible, but would need a more complex mounting bracket and attention to wheel clearance and would probably be at least another £2k. But happy to do it if there is the appetite.
That is interesting and suggests that those seeking the "german" pedal need to upgrade the master cylinder and brake booster/servo?
 

gb-gta

Member
Messages
551
Brakes, who needs them anyway, you don’t need brakes, just knock it back a couple of gears and carry more corner speed!
 

Devonboy

Member
Messages
1,054
Just had the car serviced at McGraths who thought the initial bite from the brakes was sub par considering the investment in aftermarket brake discs. Slapped on a new set of OEM pads and the braking has improved even further - much better initial bite as well improved braking from the bigger discs. Super happy now
:tomato11:
 
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Gazcw

Member
Messages
4,320
Just had the car serviced at McGraths who thought the initial bite from the brakes was sub par considering the investment in aftermarket brake discs. Slapped on a new set of OEM pads and the braking has improved even further - much better initial bite as well improved braking from the bigger discs. Super happy now
:tomato11:
I think, those stoptech pads like to be hot.
 

Bebs

Member
Messages
1,026
Looking forward to swapping front and rears out on my GT-S for these uprated Zep specials this autumn. What’s the lead time at the moment Zep?
 

Gazcw

Member
Messages
4,320
Looking forward to swapping front and rears out on my GT-S for these uprated Zep specials this autumn. What’s the lead time at the moment Zep?
Be a nice leisurely mornings work in the garage.
 

Bebs

Member
Messages
1,026
Lowering all 4 or just the rear?
Not sure yet, waiting for a fellow forum member to lower his next week with H&R front and back, before I decide. It’s either just 25 mm rear springs, or H&R 15 mm front & 35 mm rear.
 

Gazcw

Member
Messages
4,320
Not sure yet, waiting for a fellow forum member to lower his next week with H&R front and back, before I decide. It’s either just 25 mm rear springs, or H&R 15 mm front & 35 mm rear.
20mm on my qp was too much on front. I should have just done the rears.
 

Zep

Moderator
Messages
6,441
Looking forward to swapping front and rears out on my GT-S for these uprated Zep specials this autumn. What’s the lead time at the moment Zep?
Currently it is 4-6 weeks. They have been flat out all year.
 

Goodfella

Member
Messages
664
Not sure yet, waiting for a fellow forum member to lower his next week with H&R front and back, before I decide. It’s either just 25 mm rear springs, or H&R 15 mm front & 35 mm rear.
I’d be careful with the front bebs, with the standard setup I’ve scraped the front bumper a couple of times reversing off of a driveway on a slight hill.
 

Simon1963

Member
Messages
570
Currently it is 4-6 weeks. They have been flat out all year.
Is there any scope to produce for the Ghibli lll? My discs will need changing in the next year or so. I find the oem set up is reasonable but fierce on the initial bite.
 

Zep

Moderator
Messages
6,441
Is there any scope to produce for the Ghibli lll? My discs will need changing in the next year or so. I find the oem set up is reasonable but fierce on the initial bite.
It can be done, but if you are concerned that they have too much bite upgrading is probably not the answer. You might try a different pad. There are also two different set ups, the S has bigger discs and different calipers.
 

Simon1963

Member
Messages
570
It can be done, but if you are concerned that they have too much bite upgrading is probably not the answer. You might try a different pad. There are also two different set ups, the S has bigger discs and different calipers.
I’ve got the S with the original drilled discs (car only done 25k miles) the pads were changed shortly before I bought it. I don’t know what make of pads were fitted so I might take them out and have a gander. They are very dusty pads though. Any idea of a good pad or should I go OEM?