George Elliott
New member
Its a hybrid turbo, but I am 99% sure the hot side is K26. George
Engine build progress
- Thread starter TTM
- Start date
George Elliott
New member
Bob, I have less than 1000 miles on my car since fitting, so I regard it as "on test". I made the fixture for 2 reasons, its impossible to make the part properly by eye, and also, I have a spare car which may also need one. I enjoy this sort of work, but dont have a lot of spare time. I do have a good (ex Shorts aircraft trained) fabricator who now specialises in Stainless Steel, and he could perhaps produce a run of 10 off if there was interest. I have spent a good deal of CAD time getting the part right - in some ways I can understand the prices. I did not do it on my car yet, but the Crossover Pipe and DP should be thermal coated ideally. If my DP is trouble free, and there was interest from 951 enthusiasts, yes - perhaps I would make more of them. sorry for a long winded reply, but I would not want to create hassle for myself or others by making something that was a load of trouble. George
TTM
Well-known member
George, please don't feel like we're asking you to go to and back from the moon, for now just seeing some pictures would be nice, even if you feel like there is room for improvement on your current design. As Bob suggests it would be nice to have a new potential source for a DP as there are too few around (as the market is understandably very limited), and yes I'm sure we would be several people interested when you feel like the design is worth being reproduced into a small batch. I am even going to say that a complete 3" exhaust system may be of interest if you intend to design one yourself. In any case, feel free to let us know how you get on with your "projects" [
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]Here's a little site that I find useful from time to time. You can check out the different cam profiles offered at least on the 944 series. http://members.rennlist.com/951_racerx/ Here's a link to JME camshafts too. You can see that there are many others apart from the OEM ones to choose from for aftermarket modfications. http://www.jmengines.com/index.htm Also from a purely subjective p.o.v. I have recently installed a larger exhaust that I had built for a big bore project that never quite happened and the exhaust was gathering dust in the workshop. Anyway, it's quite loud but definitely 'feels' and sounds like it is helping spoolup. I don't have any real hard figures to substantiate this so just take it with a grain of salt. It's a 3" V-band outlet straight into a 3.5" downpipe (little squeezy!). Down along to a 4" ovalised pipe (for clearance), into a 5" out. No cat and barely a resonater let alone a muffler. Have to run it with a silencer around town. Actually sounds great in the car on the track though. Very racer. [] A couple of links from inside and out with new exhaust. http://www.youtube.com/watch?v=M3kG4WDTN_c http://www.youtube.com/watch?v=GNHjD3Da5RU 400+hp EVO and GT2 in the foreground. Do you like the auto weight adj mechanism? Otherwise known as the passenger seat....[&:] Not to hijack your thread Thom. Just thought both points were in context with the last couple of pages.
] A couple of links from inside and out with new exhaust. http://www.youtube.com/watch?v=M3kG4WDTN_c http://www.youtube.com/watch?v=GNHjD3Da5RU 400+hp EVO and GT2 in the foreground. Do you like the auto weight adj mechanism? Otherwise known as the passenger seat....[&:] Not to hijack your thread Thom. Just thought both points were in context with the last couple of pages.
TTM
Well-known member
Well, not intending to turn this into a pub talk, but at 20psi the 944T with a LR75 turbo may surely have a fair bit more torque than the GT3 that makes a meager 385N.m (stock 944T with K26/8 already has 350N.m). The 997 driver may not have been in the right rev range too. Well, that's Sly's side of the story anyway, and he also added in a big laugh he got spanked brake-wise at the end of the straight []
]Haha, I wish someone got the whole thing on film. Would have been funny from a few perspectives. While the GT3 really is a stunning car and unless you've been in one, you just don't realise how competent these cars are. I say competent in a fully complimentary way. They just feel so solid, fast, balanced, stable, plus the grip is outstanding. I have only been in one once. An older 996 GT3 driven by a good driver on slicks. Car was doing 1.03s at the track. He does 1.05s on R spec. In the end, I somehow finished ahead of him and could pull on him and other GT3s down the straight, so while they feel awesome and I'd love to own one, they aren't absolutely unbeatable, nor blindingly quick as Sly and others can attest. They just do everything well.
I wonder if it's possible to pull out the inner pipe if the welds were cut ?.ORIGINAL: Diver944Very interesting news. Have I read that correctly? What you are saying is the shiny new looking downpipe (on the right in this picture) is actually from an early 220 Turbo and not a 3" downpipe as sold by the likes of Speedforce and Lindsey?ORIGINAL: TTM The downpipe (the one that looks as new) has got a single section while the other one has two.
TTM
Well-known member
Everything looks at home. As for how it performs... Well... The first thing I noticed was a loss of throttle response and increase in turbo lag. As the volume the air has to go through between the turbo and the throttle body has increased, that shouldn't be surprising. On the plus side, early logs suggest exhaust temperatures are down about between 30 to 50°C. The engine sounds quieter under full load, and the torque delivery feels more widespread above 4000rpm than it did before. While peak torque feels coming later, because of turbo lag, it seems to "last longer" in higher revs. Does that suggest the IC actually is less restrictive than the original one in higher revs? While I feel I can cure the relative lag with the boost controller I am not too sure how to get back the razor sharp throttle response of the previous set up. While the car might be faster now than before, it doesn't feel it and it's a bit more work behind the steering wheel.
DivineE
New member
Nice work. Its really useful to see how it fits and where it sits. p.s. your extra lag could also be a slight leak somewhere in the new pipework? If not don't worry, I found it very hard getting used to WUF after my 3.2, they were chalk and cheese to drive. First journey I did the lag really bothered me but I soon found it less and less of a problem as I tuned in to the car and adjusted my driving. I'm sure your car is WAAY better than WUF but you can still keep the 2.5 feeling light on its feet with a bit of familiarity, I really noticed the difference when I took back over from my friend who jumped in and tried to drive it for a bit
TTM
Well-known member
Well, as much as the more widespread torque uprange suggests a restriction was removed, the lag and degraded throttle response means to me the whole set up is now crying for a bigger exhaust. Oh dear, what have I done, I feel like I have gone a step too far... Either I go back to the original intercooler or the wallet will have to take another beating until the car feels totally right back again... I'll get my coat [8|]
Extra volume in the intake means the turbo has to work harder to build boost pressure initially I guess. You need to pump more air to bring 2ltr volume to 1 bar than a 1 ltr volume to 1 bar. I guess this could be the reason for increased turbo lag. Reduction in throttle response could be for a similar reason, as you have a longer intake with greater volume the air in the intake has more mass and inertia therefor takes longer to respond to change in throttle demand.
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