K28/8 Turbo
12-10-2002, 04:34 PM
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K28/8 Turbo
Is anyone, or has anyone, run a K28/8 Turbo on their 2.5 liter 951? I'm interested in how it runs, and what the configuration was. Thanks.
12-11-2002, 05:35 PM
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a K28/8# on a 1986 944 turbo
Frist a k28 will out fit on that motor becuase of the intake manafold speedforceracing.com sell's intake mamafold if you change the manafold you can put the k28/8# but that would make your car all top end. A k27/6# made by powerhuas.com is the way 2 go.
oshin951
Frist a k28 will out fit on that motor becuase of the intake manafold speedforceracing.com sell's intake mamafold if you change the manafold you can put the k28/8# but that would make your car all top end. A k27/6# made by powerhuas.com is the way 2 go.
oshin951
12-11-2002, 05:45 PM
#4
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[quote]Originally posted by Oshin951:
<strong>a K28/8# on a 1986 944 turbo
Frist a k28 will out fit on that motor becuase of the intake manafold speedforceracing.com sell's intake mamafold if you change the manafold you can put the k28/8# but that would make your car all top end. A k27/6# made by powerhuas.com is the way 2 go.
oshin951</strong><hr></blockquote>
how can you say a K27/6 is the way to go? we have no idea what kind of set up he is looking for and there are a lot of options out there other than just the K26 , 27, ro 28 series of turbos, look at all the hybrids with different trim options that are out there.
so jaxon, let us know what you are looking for and i'm sure we can offer different tidbits of info for you.
As far as a k28/8, well that would offer a much higher hp limit, but my guess is that would be a very laggy turbo coming on some time after 4000 rpm with a stock 2.5L . But I don't have much experience with it. I do have a k27/6 and think it is a good street turbo, but it lacks the up top power I would like it to have.
<strong>a K28/8# on a 1986 944 turbo
Frist a k28 will out fit on that motor becuase of the intake manafold speedforceracing.com sell's intake mamafold if you change the manafold you can put the k28/8# but that would make your car all top end. A k27/6# made by powerhuas.com is the way 2 go.
oshin951</strong><hr></blockquote>
how can you say a K27/6 is the way to go? we have no idea what kind of set up he is looking for and there are a lot of options out there other than just the K26 , 27, ro 28 series of turbos, look at all the hybrids with different trim options that are out there.
so jaxon, let us know what you are looking for and i'm sure we can offer different tidbits of info for you.
As far as a k28/8, well that would offer a much higher hp limit, but my guess is that would be a very laggy turbo coming on some time after 4000 rpm with a stock 2.5L . But I don't have much experience with it. I do have a k27/6 and think it is a good street turbo, but it lacks the up top power I would like it to have.
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12-11-2002, 06:46 PM
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Thanks for the info 
I've been running a K27/6 with a stock boost controller. I thought it was fast until my new mechanic said both the boost and the turbo were leaking. I've seen the parts....he was right. I believe and trust this guy.
I know I am going to a Tial wastegate and electronic boost. The Tial quality looks superb. The part is massive. I'm also installing an MAF. I know...the guru is supposed to be the new way to go...but I've not found a shop in my area with experience with that set-up. This mechanic has extensive experience with the MAF. Perhaps I'll go to the guru after the MAF. If I had the time, more experience, and help, I'd tackle it myself. I'd love to take it on, but as a famous actor once said "a man has to know his limitations".
My mechanic has mentioned a K28.8, and a K27/8. That's why I asked specifically about the K28/8. You don't see or hear much about it.
I've been running a K27/6 with a stock boost controller. I thought it was fast until my new mechanic said both the boost and the turbo were leaking. I've seen the parts....he was right. I believe and trust this guy. I know I am going to a Tial wastegate and electronic boost. The Tial quality looks superb. The part is massive. I'm also installing an MAF. I know...the guru is supposed to be the new way to go...but I've not found a shop in my area with experience with that set-up. This mechanic has extensive experience with the MAF. Perhaps I'll go to the guru after the MAF. If I had the time, more experience, and help, I'd tackle it myself. I'd love to take it on, but as a famous actor once said "a man has to know his limitations".
My mechanic has mentioned a K28.8, and a K27/8. That's why I asked specifically about the K28/8. You don't see or hear much about it.
12-11-2002, 06:56 PM
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I agree with paul. I also had a k27/6 and a k27/8 and can honestly say that you will waste your time with the k27/6 as an upgrade from the stock turbo, its not worth the cost. Some people argue about the turbo lag with the #8 but the difference in lag is minimal but and the gains in the mid range and top end are substantial over the k27/6 and thats how you win races unless your into zero to sixty and even then the #6 hotside wont give you much of an advantage. The k27/8 is a good reliable street turbo that is works well with the 2.5L The k28 sounds to big for the 2.5L application. Lastly, if your going to consider something outside the k27 you should go with the garret. Most will say this is the best turbo you can get and it is cheaper than the k27.
12-11-2002, 09:04 PM
#10
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Paul sent me a comparison of his car using a K27/6 vs. a K27/8 a while back. Here's the scan:
As I recall, he said the K27/6 was run at 21psi and the K27/8 was at 18psi? That doesn't sound quite right from the chart above. I would say that both run were done at 18psi. Anyway, do a search for "K27/6 K27/8" and see what you find out there. The exhaust backpressure is the problem with the K27/6 above 15psi.
With a K28/8, you may be close to the surge (stall) limit on that turbo with a 2.5L. You might not see max-boost until 4500-5000rpm and will hit the sweet spot at 6000rpm with another 2000rpm to go, yet your engine won't be able to take advantage of that flow. The K28/8 may be better for a bored or stroked 2.8L engine.
And the K29/8 may be bested used for a 3.0L 968/S2-based turbo engine. This is what Powerhaus uses for their 968 Turbo conversions.
As I recall, he said the K27/6 was run at 21psi and the K27/8 was at 18psi? That doesn't sound quite right from the chart above. I would say that both run were done at 18psi. Anyway, do a search for "K27/6 K27/8" and see what you find out there. The exhaust backpressure is the problem with the K27/6 above 15psi.
With a K28/8, you may be close to the surge (stall) limit on that turbo with a 2.5L. You might not see max-boost until 4500-5000rpm and will hit the sweet spot at 6000rpm with another 2000rpm to go, yet your engine won't be able to take advantage of that flow. The K28/8 may be better for a bored or stroked 2.8L engine.
And the K29/8 may be bested used for a 3.0L 968/S2-based turbo engine. This is what Powerhaus uses for their 968 Turbo conversions.
12-12-2002, 11:48 AM
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Danno:
I've done some research on the archives regarding the various Turbo's. There is virtually nothing on the K28/8. Information on the other Turbo's, K27/6, K27/8 is also limited.
I always find it surprising that no one has done a systematic representation of the various configurations of the 951 both stock and modified, turbo's, boost controllers, MAF...etc. There is a a lot of information in the threads.....but no real systematic breakdown by major component, and major vendor alternatives.
It's also surprising that there aren't good video's which show procedures involved in different processes. For example...here is a video showing how to install a MAF, from start to finish. There are a few around, but nothing comprehensive. I guess it's because there is no money in it.
Sorry...I got a little off topic.
<img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" />
I've done some research on the archives regarding the various Turbo's. There is virtually nothing on the K28/8. Information on the other Turbo's, K27/6, K27/8 is also limited.
I always find it surprising that no one has done a systematic representation of the various configurations of the 951 both stock and modified, turbo's, boost controllers, MAF...etc. There is a a lot of information in the threads.....but no real systematic breakdown by major component, and major vendor alternatives.
It's also surprising that there aren't good video's which show procedures involved in different processes. For example...here is a video showing how to install a MAF, from start to finish. There are a few around, but nothing comprehensive. I guess it's because there is no money in it.
Sorry...I got a little off topic.
<img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" />
12-12-2002, 02:57 PM
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Man, that chart is perfect to compare the 2. Looks like they are almost identical on lag and power onset, but the 8 hot side has a little more oomph.
I can't wait to get my car done!!
I can't wait to get my car done!!
12-12-2002, 05:52 PM
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Hi Guys and Danno
I have some problems figuring out what line is what in the HP-chart som colours would be fine!
How much boost do you think a k27/8 can produce without just pumping heat?
What do you think is the max rwhp on a K27/8 on standard 2.5l inside but with a fine tuned camshaft and stand alone engine managment, 3"" Exhaust etc?
How much difference is it between for example a Garrett gt30 and a K27/ int terms of lag, spoolup, HP??
Thank you the knowledge i get from you guys is great!
Regards
Pete <img src="graemlins/roflmao.gif" border="0" alt="[hiha]" />
I have some problems figuring out what line is what in the HP-chart som colours would be fine!
How much boost do you think a k27/8 can produce without just pumping heat?
What do you think is the max rwhp on a K27/8 on standard 2.5l inside but with a fine tuned camshaft and stand alone engine managment, 3"" Exhaust etc?
How much difference is it between for example a Garrett gt30 and a K27/ int terms of lag, spoolup, HP??
Thank you the knowledge i get from you guys is great!
Regards
Pete <img src="graemlins/roflmao.gif" border="0" alt="[hiha]" />
12-12-2002, 08:26 PM
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Danno,
I also have one making 329.xx with the K27#8 so I am assuming the boost was higher maybe 20-21psi??
I'll see if I can get a chart of my current set-up with the Garrett to compare. We are going to dyno it in the morn. So.. I'll send you one.
Paul
I also have one making 329.xx with the K27#8 so I am assuming the boost was higher maybe 20-21psi??
I'll see if I can get a chart of my current set-up with the Garrett to compare. We are going to dyno it in the morn. So.. I'll send you one.
Paul
