spikyone 139 Report post Posted December 3, 2018 That's a shame. I think the most interesting comparison would actually be TD NA kit only vs. TD NA kit with BPBs. We all know that the TD kit works and many of us have it already, so it would have been good to find out whether the BPBs still give a worthwhile benefit on a tuned car. It doesn't need to make much bigger peak numbers, as long as it shifts the torque curve to the left as MotoIQ suggest. @Mike@TD.co.uk might be missing a chance to sell us more stuff... Share this post Link to post Share on other sites
Lauren 2259 Report post Posted December 3, 2018 You gain some torque and lose some top end. It depends what you want of course. It won't make bigger peak numbers as we've seen. Share this post Link to post Share on other sites
spikyone 139 Report post Posted December 3, 2018 1 hour ago, Lauren said: You gain some torque and lose some top end. It depends what you want of course. It won't make bigger peak numbers as we've seen. Peak numbers don't really count for much in isolation; this is about how those numbers are delivered. Based on the MotoIQ graphs, the top end loss on a stock engine is meaningless. You shouldn't get hung up on a tiny tail of the graph. The FA20 is so peaky that the BPB gains overall area under the curve; you're only losing from 6800rpm to the redline and when you upshift at redline, you'll drop to around 5500rpm (depending on gear). From 5500rpm-6800rpm you have a significant torque/power gain that more than offsets the loss above 6800rpm. Subjectively it might feel a tiny bit less enthusiastic as it won't peak at redline any more, but objectively it will make your car faster. It doesn't lose anywhere below 6800rpm so it's also better in everyday driving. The thing I want to understand is whether it gives the same effect and magnitude on a car that's already been given the TD treatment. If it does, then it could be a great mod for anyone running NA. Share this post Link to post Share on other sites
Lauren 2259 Report post Posted December 4, 2018 Looking at Ben's graph, it gives more torque (though no more than my torque peak) around 3500 instead of nearer to 4000rpm as mine does. Though it's 9bhp down on the peak in comparison at the top end. It does though give a flatter torque curve than mine from 3500 to 4500rpm. Share this post Link to post Share on other sites
Rich 378 Report post Posted December 4, 2018 On 02/11/2018 at 12:31 PM, Leeky said: From what I understand Direct Injection systems cause a lot more carbon buildup than a regular engine because of higher compression and a better burn. There are a few discussions about this on various GT86 forums but I don't actually know any UK GT86 owner that's had this issue yet. The way they clear it out is to fire walnut shell chippings at the build up under high pressure. Apparently its the best way to clear it off without doing any damage to the engine. Quick google - https://www.terracleanswaffham.co.uk/walnut-blasting My understanding is that carbon buildup in DI Engines is down to poor maintenance and I've also heard that you can get carbon buildup if you only ever drive for economy (not sure how much truth there is in the latter). But seeing as my 86 is my dedicated track car I'm happy that it should never get carbon buildup. It only ever sees low rpm on the way to and from the track lol You get it on strictly direct injected engines because combustion gases and oil (mostly from the crankcase breather) condense on the intake valve stems and leave deposits. Better fuels don't really help as the fuel never touches the valve stems. There's also not really a good way to stop it happening by driving differently or maintenance either, you just have to suck it up. The traditional solution, which the FA20 uses, is port injection as the fuel then washes down the valve stems as it in sucked into the engine. Share this post Link to post Share on other sites
benmmellor 44 Report post Posted December 4, 2018 17 hours ago, Lauren said: You gain some torque and lose some top end. It depends what you want of course. It won't make bigger peak numbers as we've seen. exactly... this works for me and my usual driving needs. The BPB's on their own did give me some more 'oomph' for general road use - the TD NA upgrade was another major game changer and the car is even better now. Chart below: - when i can find a decent image hositng site!!! Share this post Link to post Share on other sites
spikyone 139 Report post Posted December 4, 2018 7 hours ago, Lauren said: Looking at Ben's graph, it gives more torque (though no more than my torque peak) around 3500 instead of nearer to 4000rpm as mine does. Though it's 9bhp down on the peak in comparison at the top end. It does though give a flatter torque curve than mine from 3500 to 4500rpm. You can't infer anything from two different cars tested months (maybe years) apart. 9bhp is well within the normal variation between engines for the FA20, mine made more power stock than Ben's did with the BPB. You need to compare the same car with and without the BPB, ideally tested immediately before and after fitting, to see whether it's still beneficial if you already have the TD kit. Share this post Link to post Share on other sites
Lauren 2259 Report post Posted December 4, 2018 1 minute ago, spikyone said: You can't infer anything from two different cars tested months (maybe years) apart. 9bhp is well within the normal variation between engines for the FA20, mine made more power stock than Ben's did with the BPB. You need to compare the same car with and without the BPB, ideally tested immediately before and after fitting, to see whether it's still beneficial if you already have the TD kit. Of course you can. But in a perfect world.... Share this post Link to post Share on other sites
