yes, however common thinking from engine gurus is that a 54 is too big a bore for the 748 motor. I ran a 45-50-54 system on my 853r though and got a reasonable 128bhp
Agree with cranker. They'll fit, but probably not ideal for 748cc motor. Just for info, what size headers have you got?
So the plan is to run a recently purchased 748RS engine in my 748R frame that already has Ohlins and the full race Brembo brakes and Marchasini race wheels. The current 748R is fitted with a 996 50mm full system from the headers to the 996R/998s 50mm race cans, so it's a straight transfer plus a 50/54 link pipe to 54mm end cans. Still undecided on ECU but will be discussing options with the mechanic who will do the build with me. Funds and availability are still an issue but I am not going to waste the potential of my RS engine. Andy
Aaaah well that's good. A sorted rs motor might make use of the bigger cans. But unless you've already got them I'd spend the money getting it mapped with the 50mm system. It's good enough for 996SPS after all.
bearing in mind that the mono subframe is the same as the 998 bar a bracket or two, that has had the massive 63mm pipe with bigger diameter oval cans......
Android853sp - I am looking for 50mm pipes and collector for a 998R project. I do not need headers or cans. So if you want to sell please start a conversation.
I saw your wanted post but assumed the 998R is a deep sump motor so the 996sps pipes wouldn't fit. I'm about to rebuild my 748R which I will run with the 50mm system so I'm sorry the pipes are not for sale anyway. Andy
Unless they're something special then the 54mm cans will be the same size as the 50mm (and 45mm) only the inlet pipe and possibly the actual exhaust outlet pipe are any bigger. I had a (Termi) 54mm full system some years back that I acquired for my 916 but then decided against it and went with a 45 - 50mm setup and although the manifold design of the 54mm were slightly different, the rest was basically as per the smaller system and the actual carbon cans were exactly the same.
This thread has been resurrected from 2014 as I might have had a set of 50mm system pipes spare. The 54mm system that transferred to my 853(RS) is a factory titanium race system so the end cans are longer and the seat had to be relieved to accomodate them. Small price to pay because they are awesome, so awesome the noise tester at Mallory was distracted and misread the test meter, 100db at 5000rpm . Andy
My JHP Ti cans are 45mm inlet 54mm outlets with rest of the system standard 748/916 45mm, I think they were produced by JHP for the 998/996. IMHO the oversize question is really only a factor if you map and tune the engine precisely. If they are fitted with a generic open chip like many the mixture errors will mask the effect in any case (unless by chance the chip exactly matches the bike set up precisely - which very few of them do). With A Jhp sock filter, DP carbon air box and tubes my otherwise standard 748 is mapped to 95bhp at the wheel which is not far off out of the box 748r numbers with maybe 105-108 at the crank and nice straight power and torque curves, so not sure the 54mm outlets are having much negative effect. The pipes also have lasted better than I could have hoped and at £130 off ebay I am glad that was all I could afford when carbon termis were all the rage at the time, the Ti cans are much better quality and don't fall apart with age. No issues with fitting them on a biposta and they are the same diameter and almost same length as the 45mm termis of the period
