Turbos
- Thread starter homesea
- Start date
sawood12
New member
Well unfortunately no turbine can drive a compressor across the whole rev range so you either have a laggy turbo that can deliver good boost right up into the higher part of the rev range, or have a less laggy turbo that starts to run out of steam in the higher area of the rev range. Modern turbo's have a wider efficient operating window by using better compressor vane and turbine vane geometry to improve their efficiency, along with reducing the running resistance of the rotor by using better bearings, reducing the inertia of the rotor by using more exotic and lighter materials, but you can only do so much by these approaches. Ideally you need variable geometry so you can open up the area between the vanes, but this adds huge cost and complexity. So basically a decent aftermarket turbo will blow the socks off a stock K26/6 or K26/8 providing less lag than both and being able to maintain boost higher up into the rev range.
Would be nice if you could install a sort of KERS system to a turbo, so when off boost you can use a small powerfull motor to spin up the rotor for a few seconds just as the engine rpm's gets up into the boost range. Or even put a gearbox between the turbine and the compressor shafts to gear up the compressor rpm's. The problem is that you often don't have alot of room to play with and things get very very hot.
Would be nice if you could install a sort of KERS system to a turbo, so when off boost you can use a small powerfull motor to spin up the rotor for a few seconds just as the engine rpm's gets up into the boost range. Or even put a gearbox between the turbine and the compressor shafts to gear up the compressor rpm's. The problem is that you often don't have alot of room to play with and things get very very hot.
TTM
Well-known member
It all depends if you are ready to budget for a custom exhaust to fit a non-hybrid unit such as a Garrett, Holset, etc.
If like me you prefer to reallocate the potential budget needed to modify the exhaust to a hybrid turbo of superior quality that will use a KKK hotside, then I would suggest you to call SPS.
They, I believe, have already provided turbochargers in various sizes/forms to several 944 turbo owners so they should have a signficant feedback and be able to build you a custom turbo that will fit your requirements.
Pauertuning in Canada seem to offer interesting hybrids for a lower investment.
If like me you prefer to reallocate the potential budget needed to modify the exhaust to a hybrid turbo of superior quality that will use a KKK hotside, then I would suggest you to call SPS.
They, I believe, have already provided turbochargers in various sizes/forms to several 944 turbo owners so they should have a signficant feedback and be able to build you a custom turbo that will fit your requirements.
Pauertuning in Canada seem to offer interesting hybrids for a lower investment.
Well you have to have supporting mods to make them work also. So you can't just slap on a bigger turbo and hope for the best. The 26/8 with some chips isn't so bad really, but it depends on your budget. If that isn't enough power, then maybe consider saving up for one of these proven kits like the Vitesse Race stuff. They have many enthusiastic proponents and it is tunable.
Also something to remember, not all aftermarket turbos will fit so you have to consider that in your plans. I would guess for approx 2500 UK pounds you could get a full standalone with custom harness, maps, and a something like a GT or BW turbo. Plus you don't have to stop there.....
Also something to remember, not all aftermarket turbos will fit so you have to consider that in your plans. I would guess for approx 2500 UK pounds you could get a full standalone with custom harness, maps, and a something like a GT or BW turbo. Plus you don't have to stop there.....
You do get anti lag systems, just an electric motor to drive the turbo at low exhaust velocity. Just run it off the alternator...
As for small turbo's becoming restrictive at high exhaust gas flow cant you just fit a larger waste gate or similar device to allow excess exhaust gas to flow relatively unrestricted around the turbo?
George Elliott
New member
Tom, I am not an expert on Turbo technology, but in addition to the comments already made - I can recommend a solution.
I recently had the same question in my mind as you ask here. I called SPS and ended up with a 944 with a modified turbo.
In summary it is a modified KKK, and it brings the simple old technology in the KKK up to date with different bearings and clever engineering tweeks. What does it mean on the road every day?
Less lag
More power
Good economy
Nice power delivery profile
Much improved torque
Zero Oil useage - (totally incredible, I keep checking it thinking the sump level sensor is u/s)
Wafting along at 2300rpm without lag is a nice feeling. (I have 0.5psi boost at 1900rpm) Slowing to 35mph in 5th through a village with slow moving traffic and returning to 60mph without changing gear and without complaint from the engine is marvellous -especially after 50k miles with a K26/8. Full bore 3rd / 4th gear from 4500rpm is interesting too.
I could go on, I was very fortunate to find what I call an X50 951 off the shelf.
If you want a real fast turbo - get a 996TT, they are good value now and a 944t with 450bhp will cost as much or more.
If like me you want a lovely driving 944t which will hold its own with a 996tt in the real world, then I'd recommend speaking to SPS.
The turbo does need tuning with other components and thats where I think my car scores highly.
Good luck with your car
George
944t
964
I recently had the same question in my mind as you ask here. I called SPS and ended up with a 944 with a modified turbo.
In summary it is a modified KKK, and it brings the simple old technology in the KKK up to date with different bearings and clever engineering tweeks. What does it mean on the road every day?
Less lag
More power
Good economy
Nice power delivery profile
Much improved torque
Zero Oil useage - (totally incredible, I keep checking it thinking the sump level sensor is u/s)
Wafting along at 2300rpm without lag is a nice feeling. (I have 0.5psi boost at 1900rpm) Slowing to 35mph in 5th through a village with slow moving traffic and returning to 60mph without changing gear and without complaint from the engine is marvellous -especially after 50k miles with a K26/8. Full bore 3rd / 4th gear from 4500rpm is interesting too.
I could go on, I was very fortunate to find what I call an X50 951 off the shelf.
If you want a real fast turbo - get a 996TT, they are good value now and a 944t with 450bhp will cost as much or more.
If like me you want a lovely driving 944t which will hold its own with a 996tt in the real world, then I'd recommend speaking to SPS.
The turbo does need tuning with other components and thats where I think my car scores highly.
Good luck with your car
George
944t
964
My mechanic Sean has a VR stage 3 and it's pretty quick. It's as fast on a track as my setup with a Stage 5 as it spools earlier. I know what you mean about not liking turbo cars that are too linear but this one isn't. Definitely quicker than a k26/8 but the VR stuff doesn't come for free.
George,
That is great info and just what I was looking for. I feel at the moment I am pushing my k26/6 as far as it will go. Maybe with a new exhaust and vitesse kit I could get a few more bhp. But the main fact is you cant push a k26/6 over 300bhp and make it nice to drive. Can I be checky and ask the cost George?
As to buying a 996, I do have a soul.
That is great info and just what I was looking for. I feel at the moment I am pushing my k26/6 as far as it will go. Maybe with a new exhaust and vitesse kit I could get a few more bhp. But the main fact is you cant push a k26/6 over 300bhp and make it nice to drive. Can I be checky and ask the cost George?
As to buying a 996, I do have a soul.
George Elliott
New member
Nick, sorry for late response, I have been busy unfortunately. Simon may see this post or you could call Jon Mitchell's Garage in Bournemouth.
Tom, I cant quote numbers as I bought the Car with the mods installed. I would comment that the standard of finish is high, the results are clear. I initially enquired about a "turbo package" but there are many associated component mods. Speak to them for sure. ( They wont try to fob you off with a 996[
])
Thom, my comment was only to illustrate the flexibility / tractability of the engine package, I guess the engine is making less than 100bhp below 2000rpm, so it does not strain the components, but no - its not the way I always drive. In fact I find myself looking for 6th gear at the other end of the scale....
George
944t
Tom, I cant quote numbers as I bought the Car with the mods installed. I would comment that the standard of finish is high, the results are clear. I initially enquired about a "turbo package" but there are many associated component mods. Speak to them for sure. ( They wont try to fob you off with a 996[
])Thom, my comment was only to illustrate the flexibility / tractability of the engine package, I guess the engine is making less than 100bhp below 2000rpm, so it does not strain the components, but no - its not the way I always drive. In fact I find myself looking for 6th gear at the other end of the scale....
George
944t
sawood12
New member
Keep an eye on the $ vs £ exchange rate - it's getting cheaper. Besides the VR stuff is a heck of alot cheaper than the alternatives (tuning the stock EMS or fitting standalone and tuning) and will give you much better results with minimal faffing. In my view it is the only off the shelf MAF kit to go for on a turbo. When things start to settle down with the whole economy thing and baby #2 has popped and the wife is back at work I'd like the VR kit with an SPS turbo.
It may not be as much fun to do but you will have someone to talk to and know the end. The trouble with doing your own thing is some bits work together and some bits don't and then need swapping for more expensive bits which means you have wasted money trying to save money.
I have nothing but admiration for Simon at SPS. For a man who designed and built miniature jet turbine engines turbos are simple technology. While the rest of us approach nut cracking with a sledge hammer he does it with a micrometer. The results are almost identical but the execution is far nicer.
Well I put things on a back burner for a bit as the 944 is now my daily drive and its fast enough to get me to work!!
When John had my car it was running 280ish bhp on the 26/6 and when I get round to changing the chip set back over it should be near that again. So 300bhp cant be that hard on a 26/6.
My plans change for the car every day, I guess thats part of the fun for me with the 944 turbo that it has so many different upgrades avaliable.
When John had my car it was running 280ish bhp on the 26/6 and when I get round to changing the chip set back over it should be near that again. So 300bhp cant be that hard on a 26/6.
My plans change for the car every day, I guess thats part of the fun for me with the 944 turbo that it has so many different upgrades avaliable.
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