Ztox 230 Report post Posted October 27, 2016 The K-Sports on the TD car certainly slow you down! I can say that much lol. Share this post Link to post Share on other sites
KevinA 695 Report post Posted October 27, 2016 Just as good 1 Ztox reacted to this Share this post Link to post Share on other sites
Special K 442 Report post Posted October 31, 2016 I had a number of issues with K-Sports, probably the most noticeable was the amount of pedal pressure required. They also got very hot But Stoptechs also have an issue with the rear caliper pad retaining pins. These are meant to be held in place by a central groove which is located by the metal spring which holds the pads in place - I had a case of this pin coming out - literally - and the pads moving. Abbey Motorsport have developed modified pins held in place by circlips and I would recommend this mod. Spec K Share this post Link to post Share on other sites
Bfranklyn86 52 Report post Posted November 1, 2016 On 31/10/2016 at 5:22 AM, Special K said: I had a number of issues with K-Sports, probably the most noticeable was the amount of pedal pressure required. They also got very hot But Stoptechs also have an issue with the rear caliper pad retaining pins. These are meant to be held in place by a central groove which is located by the metal spring which holds the pads in place - I had a case of this pin coming out - literally - and the pads moving. Abbey Motorsport have developed modified pins held in place by circlips and I would recommend this mod. Spec K That's interesting, thanks. I hadn't come across this when researching the Stoptechs - most people tend to swear by them. And the AP ones for that matter. The Stoptechs would necessitate either some spacers or new wheels. I could get the Stoptechs and some fox fx005s for the price of the APs. Which would save a good amount of unsprung weight, but I'm not really a fan of the look (of aftermarket wheels). The APs increase the front braking bias, whereas the Stoptechs do not. Having a big lump of a supercharger on the front has already moved the brake bias rearwards slightly from stock (by how much I have no idea) so the APs would compensate for this, but probably overcompensate moving the bias forward further. I spoke to someone technical at AP racing yesterday who said they ensure all of their front road kits keep below 18% extra braking tourqe vs stock so as not to mess with the balance too much or upset ABS. They have tested this kit with with the stock 86 rear brake set up and were fine, but did recommend a DS2500 pad on the rear. He also said they had worked very hard to get this to fit under the stock wheel! Anyone had problems with too much front bias? Share this post Link to post Share on other sites
Ade 517 Report post Posted November 1, 2016 Did you speak to Pete Collen? The 332mm AP kit for the gt86 is almost exactly the same as the stock bias. My spreadsheet puts them at about 70% to the front. Happy to send you the spreadsheet if you want to use it for other brake kits. You need to put in the piston diameters, disc diameter and pad swept area to compare to stock. Share this post Link to post Share on other sites
Bfranklyn86 52 Report post Posted November 1, 2016 Thanks for the offer Ade. I'll take your word for it on the APs. It was Pete Cullen who I spoke to. He told me he didn't think the kit would have an appreciable impact on the bias. Share this post Link to post Share on other sites
Church 209 Report post Posted November 1, 2016 Under 18% bias change vs stock bias? "recommend use different brake pads in rear"? These both bits would tell me to stay away from these kits, as i translate them that brake vendor haven't bothered about brake bias or has targeted with kit some very specific suspension & aero setup. Essex's Sprint & Endurance kits were within 1-2% from stock bias, other kits like willwood/RR and so on IIRC within 5%, and that's with same compound pads front-rear. P.S. Easier to loose traction with power-oversteer after installing forced induction has nothing to do with brake bias. FI doesn't impact it in anyway. Suspension parts, adjustments and front-rear downforce from aero parts does (striking out weird possibilities like staggered tire choice and front:rear weight balance, which i doubt to change noticeably from weight of FI parts). Share this post Link to post Share on other sites
Bfranklyn86 52 Report post Posted November 1, 2016 9 minutes ago, Church said: Under 18% bias change vs stock bias? "recommend use different brake pads in rear"? These both bits would tell me to stay away from these kits, as i translate them that brake vendor haven't bothered about brake bias or has targeted with kit some very specific suspension & aero setup. Essex's Sprint & Endurance kits were within 1-2% from stock bias, other kits like willwood/RR and so on IIRC within 5%, and that's with same compound pads front-rear. P.S. Easier to loose traction with power-oversteer after installing forced induction has nothing to do with brake bias. FI doesn't impact it in anyway. Suspension parts, adjustments and front-rear downforce from aero parts does (striking out weird possibilities like staggered tire choice and front:rear weight balance, which i doubt to change noticeably from weight of FI parts). Sorry if my post wasn't clear. I think what he was saying that none of their road kits have more than 18% more braking power than the stock equivalents but I don't think this translates into an 18% shift in the brake bias, and for this kit apparently there is no change in bias. Extra weight on the front (e.g. A supercharger) moves the bias towards the rear because, if all else remains equal, there is less braking power on the front vs the weight over it and the extra grip it can get. Share this post Link to post Share on other sites
Church 209 Report post Posted November 1, 2016 That weight is too small to be taken into account. How much SC weights? How much car weights? How big difference can be felt by human "butt dyno" (placebo aside)? I doubt you feel difference in weight shift of car vs full or almost empty tank, even though that weight difference is 3 times SC weight. Share this post Link to post Share on other sites
Bfranklyn86 52 Report post Posted November 3, 2016 It might well be imagined, but turning in to tight corners quickly is where I feel I notice the extra weight (20-30kg I believe, which is comparable to a tank of fuel) of the Harrop. One of my mates who'd seen the car before and after asked me if I'd had it lowered! Obviously the car is much faster than it was before though and I'm very happy with the kit, but just saying. Anyway, I went with the AP racing 332mm kit. Very excited to get it on and get the car on track in the new year. I'll probably avoid doing any other significant mods for a while. This thing is fast enough and now should have the braking performance to match. Time to leave things be. Share this post Link to post Share on other sites
Ade 517 Report post Posted November 3, 2016 1 hour ago, Bfranklyn86 said: It might well be imagined, but turning in to tight corners quickly is where I feel I notice the extra weight (20-30kg I believe, which is comparable to a tank of fuel) of the Harrop. One of my mates who'd seen the car before and after asked me if I'd had it lowered! Obviously the car is much faster than it was before though and I'm very happy with the kit, but just saying. Anyway, I went with the AP racing 332mm kit. Very excited to get it on and get the car on track in the new year. I'll probably avoid doing any other significant mods for a while. This thing is fast enough and now should have the braking performance to match. Time to leave things be. Excellent Choice! What pads did you order with it? Share this post Link to post Share on other sites
Bfranklyn86 52 Report post Posted November 3, 2016 Thanks! The kit comes with some APF404s, which I'm told are similar to the Ferodo DS2500s. Share this post Link to post Share on other sites
will300 812 Report post Posted November 4, 2016 @Bfranklyn86 look what @James@Amber has shared on Facebook today. Share this post Link to post Share on other sites
Bfranklyn86 52 Report post Posted November 4, 2016 That's the look I'm after. Discrete but classy. Except on mine there will be a car attached too! These things can't get in my life soon enough. Share this post Link to post Share on other sites
Foulsmell 120 Report post Posted November 5, 2016 Will the brakes be too powerful for the tyres? Stock size are naf. Sent from my iPhone using Tapatalk Share this post Link to post Share on other sites
Deacon 1357 Report post Posted November 5, 2016 1 hour ago, Foulsmell said: Will the brakes be too powerful for the tyres? Stock size are naf. Sent from my iPhone using Tapatalk You can get plenty grippy enough 215/45/17's 1 Lauren reacted to this Share this post Link to post Share on other sites
Darth Raknoor 1 Report post Posted July 15, 2020 Random questions about the AP's.... Would the increased braking power require a change of suspension and would they fit behind a set of Work S1R's sized 17x7.5 et35? Share this post Link to post Share on other sites
Church 209 Report post Posted July 15, 2020 Wheel clearance is specific to brake kit and to specific wheel (of specific sizing) kombo. Check info on vendor's site or via email enquiry. Also you can search on brake vendor's site for brake fitment template, download that pdf, print, glue on carton & cut by contours, and then check on your wheels. Also you may try to search on forums, if someone by chance has specific brake kit and specific wheels. Sometimes some not-clearing brakes cases can be workarounded by using wheel spacers. Specific wheel size of diameter/width/offset alone is not enough to ensure fitment, just increases chances to fit. After all, it may depend also on spoke shape, and that shape may differ between different wheel types and between different widths/offsets of specific wheel (like with offsets such and such it's one "face" of wheels of specific concavity, and for other offsets - different "face"). Increased braking power .. sounds like you are under impression of some populistic myths. Stopping distances mostly depend from tire grip only. If "less powerful" [tm] brakes are still capable to brake till wheels are locked/ABS triggered, car will not stop sooner. At most only brake pedal travel may differ. Main thing that "big brake kits" offer - increased heat capacity. They can "store" more heat and cool off at faster rate, resulting in longer heavy braking time before some issues pop up from overheat (eg. brake fluid boiling, brake pads overcooked/glazed and such, resulting in "brake fade"), thus eg. longer tracking sessions with rest being same, or eg. still acceptable brake functioning time even if you have to brake more (from eg. higher speeds due forced induction, or from higher speeds reached due grippier tires/more aero downforce mods). Nothing suspension related. Share this post Link to post Share on other sites
Rich196 103 Report post Posted July 15, 2020 4 hours ago, Darth Raknoor said: Random questions about the AP's.... Would the increased braking power require a change of suspension and would they fit behind a set of Work S1R's sized 17x7.5 et35? A church said, you do not require to change suspension to use a BBK however, if with you current choice of tyres you can lock the wheels its pointless fitting a BBK. If however your using stickier rubber and you cannot lock the brakes with them then a BBK will give you increased performance. For reference have the Rayland 330mm kit: http://www.reyland.co.uk/subaru-impreza/ It fits under my Rota Boost, 17x17.5 E48 with a 15mm spacer. It also fits under my XXR 527 18x8.75 E35. 1 Darth Raknoor reacted to this Share this post Link to post Share on other sites
sam534 62 Report post Posted July 15, 2020 A church said, you do not require to change suspension to use a BBK however, if with you current choice of tyres you can lock the wheels its pointless fitting a BBK. If however your using stickier rubber and you cannot lock the brakes with them then a BBK will give you increased performance. For reference have the Rayland 330mm kit:http://www.reyland.co.uk/subaru-impreza/ It fits under my Rota Boost, 17x17.5 E48 with a 15mm spacer. It also fits under my XXR 527 18x8.75 E35.Heat management is the main reason for bbk not braking force?Sent from my COL-L29 using Tapatalk Share this post Link to post Share on other sites
Kaltorak 111 Report post Posted July 15, 2020 1 hour ago, sam534 said: Heat management is the main reason for bbk not braking force? Yup. Stock brakes can lock your tires already, so you literally cant gain from more braking force. However, give it 15 or so 60to10mph hard brakes, and suddenly your stock system isnt stopping you as well as the brakes are fading. BBK will take longer to start that fading process. NB - Its also for looks. 1 sam534 reacted to this Share this post Link to post Share on other sites