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There's also a rennlist member E-man930 that has a local shop modding K26-8 turbos with billet compressor wheels, and ported hot sides, that are sopposed to spool faster than a regular 26-8 and do 330-350 whp. I just bought one from him, so I don't have dyno numbers yet, but hopefully this winter I'll have some numbers. I think he might need to have a small batch of guys to make it cost effective.
I received my nodded k26-8 this weekend. The changes look subtle in the pictures, but there's a lot of work done. I didn't realize the compressor is about 5mm bigger than a regular 26. I'll make a separate thread with dyno results this winter
Looks good. I wonder how a ported #8 compares to a standard #10 turbine housing. And what size down pipe would be used to avoid a mismatch at the turbo ?
My plan is to get the 3" vband downpipe from SFR, and cut the neck off of my 3" Lindsey exhaust to get a full length 3" setup. Can't answer the hot side question legitimately, but my guess is the turbine wheels would still be different. Again, just speculation on my part, I haven't studied it
Exhaust tuning is a black art. I've run systems with minimal silencing, and even no silencers on 2 and 4 strokes and maybe gained top end/noise at the expense of bottom end/mid range. Bigger is not always better, particularly on an engine that is all done under 7k.
Any idea what the Vitesse Stage 3 with actually put down with supporting mods? There doesn't seem to be many results. The website says 310-330whp at 15psi, which is pretty low and should be much more cheaply attained with a K27/6. That doesn't mention an exhaust/wastegate though, so if adding that and a couple more psi would crank up the numbers, that would be much better.
The most results that come up are for the old stage 2 that he claimed would make 410whp at 20psi. If they make 12-15whp per psi like he says, that would be 335-360whp at 15psi, though there was big contention it could do that without an exhaust on a stock engine. Did the old stage 2 flow as much or more than a current stage 3, or why are the claimed stage 3 power numbers much lower now? Are they more realistic without an exhaust?
And a 13 year old stage 3 made 380-390hp on 18-19psi, on 100 octane though. Still less than that stage 2 claim on pump.
You mentioned wanting 350+ HP... do you have a more specific goal - ie "350"? Probably you want to start thinking about it top down - ie what number you want to hit. That will then lead to the boost pressure required, and then to the turbo which will best support that in its efficiency range. Otherwise you could end up with a bunch of piece parts perhaps not well mated. For certain you don't want to end up with a turbo not well mated - either before the surge line or outside the efficiency island creating backpressure and cooking your engine.
Somewhere in the 350-400whp range would be nice, depending what is realistic on pump. I'd consider W/M injection, which should be a pretty solid power boost, but not many people seem to be running it. It would be easier if it could hit that range without it though.
Build a 3.0l 8v and run 16 psi pump gas. You'll have what your looking for without as many engine rebuilds. How many agree over 300WHP out of a 2.5 will require more often engine rebuilds vs a 3.0L with the same power usually running less boost? Or get one from Larts. https://www.ebay.com/itm/252573402602
Any idea what the Vitesse Stage 3 with actually put down with supporting mods? There doesn't seem to be many results. The website says 310-330whp at 15psi, which is pretty low and should be much more cheaply attained with a K27/6. That doesn't mention an exhaust/wastegate though, so if adding that and a couple more psi would crank up the numbers, that would be much better.
The most results that come up are for the old stage 2 that he claimed would make 410whp at 20psi. If they make 12-15whp per psi like he says, that would be 335-360whp at 15psi, though there was big contention it could do that without an exhaust on a stock engine. Did the old stage 2 flow as much or more than a current stage 3, or why are the claimed stage 3 power numbers much lower now? Are they more realistic without an exhaust?
And a 13 year old stage 3 made 380-390hp on 18-19psi, on 100 octane though. Still less than that stage 2 claim on pump.
My old 86 turbo was rebuilt with an early model Vitesse Stage 2 turbo, SFR 3 inch down pipe, 3 inch Lindsey full exhaust, Magnaflow cat. SFR stage 1 headers, and full M-tune with 80 lb injectors.
It put down 323 RWHP at 18lb boost. 326 ft/lb RWTQ.
Build a 3.0l 8v and run 16 psi pump gas. You'll have what your looking for without as many engine rebuilds. How many agree over 300WHP out of a 2.5 will require more often engine rebuilds vs a 3.0L with the same power usually running less boost? Or get one from Larts. https://www.ebay.com/itm/252573402602
From what I've seen here over the years, 275-325 rwhp from the old 2.5L 8v can be done fairly reliably with bolt ons. Beyond that can get very expensive and time consuming (and require a lot more than bolt on upgrades).
If I were looking for 350-400+ and wanted a driveable and reliable car, I would look to another platform as a starting point. This could either be 3L 944 variants, or something like a 996TT which are still priced really well (40-50k) and can yank you out of your skin in stock form and be turned into FrankenTurbo with some mods.
From what I've seen here over the years, 275-325 rwhp from the old 2.5L 8v can be done fairly reliably with bolt ons. Beyond that can get very expensive and time consuming (and require a lot more than bolt on upgrades).
Quite a few years ago a couple of owners over here threw most of the Lindsey catalogue at their 2.5 turbo engines, both made over 400 crank bhp on a stingy dyno. AFAIK they're both still running well.
Quite a few years ago a couple of owners over here threw most of the Lindsey catalogue at their 2.5 turbo engines, both made over 400 crank bhp on a stingy dyno. AFAIK they're both still running well.
As soon as you said 400 crank bhp, Lart's eyes cracked open, his leathery wings unfurled, and he took flight into the night
Yeah, looks like on pump, easy bolt ons won't push you much past 320whp.
But what about W/M injection? It is cheap (<$1k for the best kit) and looks like it should easily push you up to higher 300whp or more possibly with decent bolt-ons, similar to race gas.
For background, I daily drive a 400awhp Audi S4. It does weigh ~500lbs more, but I don't want to dump $10k into this drivetrain just to be disappointed.
10-16-2016, 10:00 PM
