[/quote] What has the turbo been designed for, might be interested! [/quote] Hi, our posts seem to cross! Originally I wanted to make a decent amount of extra power but not at the expense of lag. The SFR level 1 or 2 seemed about right and after chatting with Tim there (really nice guy) he suggested something in between and spec'd a Garrett t04b compressor with a 46 trim wheel mated to a size 6 kkk hotside machined to take a slightly larger turbine. He said it would "spool faster than a k26/8 or a k27/6 and outflow a k27/8". (his words not mine) I don't really understand flow v boost but at 14 psi it is supposed to flow a lot more air than a k26/8 at the same pressure - don't know how that works - but even at 1 bar you would still need more fueling than you currently have. I'm running it at about 16-17 psi quite happily, however 18 psi (1.2 bar) and higher is really outside it's efficiency range. It will bolt straight on and uses the original water and oil connections but you would need a few minor mods to connect your intake to it. I can probably find some pics of it next to my k26/8 if you are interested. btw, apologies for highjacking the thread Thom!
Engine build progress
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DivineE
New member
I'm curious now, who is GPF? I feel I should know you if you've been around some time elsewhere and have a nice modified turbo. Is that the RPM built car that you own? Sounds like the same set-up. If so that's a beautiful car that, drives really nicely. There seem to be a few people interested in a bigger turbo on this thread so if your interested I 'may' have a modified LR75 turbo up for sale shortly. It fits in place of the standard unit, KKK /8 hotside and Garrett cold side, brand new and never used. The american turbos tollerances can often be improved upon so I had a company here strip the turbo down and do some machining work to some of the internals. It has now been high speed ballanced to 0.4g at 70,000rpm compared to the standard unit which came ballanced to 1.75g at 70,000rpm. It should be capable of giving a reasonable torque curve because the graph below is with my car using a standard LR75
Hi Ben - it is you, isn't it?? It's Graham from Titanic - we've met at Dyno Days and auto jumbles in the past - I have a Zermatt Silver '88 Turbo S and remember showing you some data logging I was doing on a laptop at one of them - if I could work out how these avatars work I'd put a picture up! I'll put my mods in my sig later. Can't believe Rick sold WUF, or that you haven't bust it yet!
] May be intersted in the turbo - is this the one you got from MarkK? I'd need bigger injectors (again) with that..... Best Regards
] May be intersted in the turbo - is this the one you got from MarkK? I'd need bigger injectors (again) with that..... Best Regards
DivineE
New member
Ahh ha! Yes I remember. Nice to put a face to the name. Excellent. Another really nice 944 I had forgotten all about. Glad she's still going strong. Well you know all about WUF then! Yes I'm thinking about selling the turbo I got from Mark, selling the (yet to be re-built) one from my car and putting the money together to buy 1 ball bearing turbo. I know I shouldn't and I don't need to if I've got to go to the hassle of changing a part like the turbo and I know it could be improved upon, I just don't think its in the spirit of a car like WUF not to carry on the development?! It'll grate at me to know I've gained nothing for my hard work. I'm not 100% decided.. but I'm swinging more toward that way of thinking at the minute. p.s. still grateful for you taking the time to start to try and explain it to me, I'm going to be needing to do a lot more learning now I've got WUF.[]
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Diver944
Active member
You'll really struggle holding 1 bar to the redline. When my K26/6 car had a Greddy EBC fitted to a dual Port wastegate it still dropped back to 0.8bar by the redline. Take a look at these other modded K26/6 cars from Ricks Dyno tables and you'll see they all drop off at higher RPM:
Thanks for the info and dyno charts, all look very similar to how my car behaved. Can't quite bring myself to re-fit the k26/6 after all the work, despite the guys I had rebuild it doing an epic job making it like new! Edit: Just noticed that one of them is for my car, E905WWD, Scott's old car! Its all in bits in my garage atm! My father has just got a 1965 mini cooper which he is rebuilding, kinda stalled my project a bit!
sawood12
New member
ONe thing that will help a K26/6 hold 1 bar till higher RPM is a MAF or MAP i.e. removing any restriction in the intake. This will help the turbo breath better. I reckon you could hold it higher, maybe for 500 to 1000 rpm if you've got good boost control, but to hold it to the red line might be a tall order. Some guys in the states reckon they've done it. The thing that determines if it is possible is the capacity of the turbo. If the turbo cannot physically flow enough air to maintain pressure at high RPM then it is not possible. I liked the characteristics of the K26/6 -it spooled up pretty well, wasn't as on/off as larger turbos in that it seemed to start picking up at around 2k rpm then building upto max boost at around 2500 to 3000rpm. Larger turbo's always feel to me like they are a bit more on/off than that. I'm sure Vittesse was looking at developing a modernised K26/6, with bb's and a new compressor wheel to improve capacity and spool up. I think it was aimed at those not after more low to mid range performance and was good for over 300bhp when married to his MAF kit. I'm sure he got some silly HP out of one running 1 bar boost with his MAF and vflex kit and his 'Sledgehammer' modified head. My memory could be failing me though.
Scott, I think this is indeed a fond memory. [
] Look at the graphs above - not one of them builds max boost by 3000rpm - all of them are 3500 or over.... Sure the k26/6 spools a bit earlier than the 26/8, but not that much and can't make the same power - not that I've ever driven one mind you. Regards Graham
sawood12
New member
You're definitely right Graham, plenty of fond memories and not very many not so fond ones. However I will say that dyno plots are all well and good but they don't necessarily tell you how the car feels to drive. On the road my old car definitely felt it started to pull quite early on (much earlier than the plot above would suggest) and the build up of boost felt smooth and progressive, even though it didn't achieve max pressure until 2500 to 3000 rpm. Tom - looks like you're looking after my old car. Nice to see she's effectively being reborn. Looking forward to hearing initial running reports!ORIGINAL: GPFScott, I think this is indeed a fond memory. [
Lots to do scott! Going to strip all the suspension components off for a full chassis rust treatment with new bushes, new copper brake/fuel lines, rebuilt wishbones etc etc. Get lots of the bits shot blasted and re-painted/coated. Hopefully all the engine work can be done pretty much in parallel, going to send the head off to be modified and rebuilt. New wastegate, new clutch and fully rebuilt engine. Got an original bridge spoiler to go on too. Going to try and get some bits of OS951, they seem to make some great kit over in finland! Final step will be a custom remap and then hopefully many hours of good driving and some track days! Exciting stuff but lots of work and a fair bit of the old ££££.
DivineE
New member
I don't know, he seems a genuine and open kind of chap, plus solo's car which your may or may not know is a very serious bit of kit. To achieve those second numbers on the second dyno made me wonder if it was possible? The injectors I'm certain are too small but maybe his additional meth is giving him the boost he needs?! It has made me more determined to get a BB turbo for my car though and release any potential I might be losing though the turbo. A couple of notes on the above, isn't anyone else thinking that turbo is a k26/8? As for the boost showing later on the dyno, that looks like the normal run of things by looking at the recent thread on rennlist. Everyone seems to spool up 500 rpm or so earlier on the road than on the dyno. Something to do with loads or so they say.
I think anyone who is contemplating changing their turbos should really look to the BB versions. I haven't got anything logged just yet, but will have some dyno work done in the very near future. All I can say is that they 'feel' very responsive, but you can also hear them clearly spooling before you've got your foot flat to the floor or are in the prime boost / tq range. Sort of like a truck going uphill. Clearly technology has progressed in many fields and turbos are no exception. For turbos as small as k26/6 and /8s they still don't really spool up with any alacrity by comparison to the Garrett BB turbos in my experience, plus they fall off in the upper rpms and just don't create enough power too. As for the numbers from Asian Caucasian's car, well as usual, it's just a number. Even though it's from a Dyno Dynamics version, we don't know if that was in shootout mode. I'd bet that it was. This will inflate the figure quite a lot. He's also running 21.5 psi. I don't believe many of you guys are up in that boost range. The methanol injection would help a lot and he's had a proper fuel and ign tune. Anyway, I would just say that in some cases you have to go to a bit of trouble to mount a BB turbo, but you may just need a mount and a little bit of modifying the downpipe and X-over. Not much work for a decent mechanic. Well worth it in my book.
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