Calling on 6 speed conversion guys
06-18-2018, 02:23 PM
#1
Three Wheelin'
Thread Starter
Calling on 6 speed conversion guys
researched and can't find answers: perhaps a few of those who have done 6 speed Z06 conversions can weigh in:
considering a 6 speed swap in my car, and wonder if folks are over the top happy, just neutral, or disappointed with results?
I have a stock engine and often wish I had another gear. doing the math, I can see that this would make the car a much
more enjoyable highway cruiser, but would like to hear about off the line performance.
at the lower end, are zero to 60 times faster, the same, or not as good? from previous posts, I can't decipher if there is only
the motorsports option for a kit to purchase? seems that others have done the conversion as well?
considering a 6 speed swap in my car, and wonder if folks are over the top happy, just neutral, or disappointed with results?
I have a stock engine and often wish I had another gear. doing the math, I can see that this would make the car a much
more enjoyable highway cruiser, but would like to hear about off the line performance.
at the lower end, are zero to 60 times faster, the same, or not as good? from previous posts, I can't decipher if there is only
the motorsports option for a kit to purchase? seems that others have done the conversion as well?
06-18-2018, 02:31 PM
#2
Administrator - "Tyson"
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The big question that's always in the back of my mind with this conversion, what are the negative effects from replacing or modifying the rear cross member? This isn't a trivial change or modification and most seem to overlook it.
Unless someone pays a ton of money to have the various ways to do this conversion fully stress tested compared to an original one, I'm not sure I'd ever be comfortable with this swap, as least with the various way's I've seen it done so far.
The rear cross member is one of the key elements of what makes the overall 928 chassis what it is. Cutting this up or replacing it shouldn't be taken lightly.
I don't understand this hang-up of having an engine at 3k rpm or even higher when going down the highway. It's not hurting the engine at all, and if that's such a bother, drop in a different 928 transmission with a 2:20 R&P.
I'm dropping in a different year trans into my 87 to shorten up the R&P.....
Unless someone pays a ton of money to have the various ways to do this conversion fully stress tested compared to an original one, I'm not sure I'd ever be comfortable with this swap, as least with the various way's I've seen it done so far.
The rear cross member is one of the key elements of what makes the overall 928 chassis what it is. Cutting this up or replacing it shouldn't be taken lightly.
I don't understand this hang-up of having an engine at 3k rpm or even higher when going down the highway. It's not hurting the engine at all, and if that's such a bother, drop in a different 928 transmission with a 2:20 R&P.
I'm dropping in a different year trans into my 87 to shorten up the R&P.....
06-18-2018, 02:51 PM
#3
Three Wheelin'
Thread Starter
I don't understand this hang-up of having an engine at 3k rpm or even higher when going down the highway.
that I am doing my car a favor.? please tell me I have no idea what I am talking about; lol I would love to hear that, and perhaps scrap this whole notion.
does lower rpm's help with the whole oil ingestion issue, which might not be an issue at all?? unfortunately, I read as much as I can, and I am sure a lot of
it is like a George Carlin quote on marketing and sales: "its all bull****, and its bad for you."
06-18-2018, 03:13 PM
#4
Administrator - "Tyson"
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I've been in the 928 word over 25 years and it's never concerned me.
Tiny German 4-bangers are designed to spin at 4k all day long down the highway (like my wife's Bug).
Lower rev's carry with them a different concern. Say you are now lumbering along at 1,500rpm with your Vette trans and decide to speed up and floor it, you are now in an area of the curve and with that load susceptible to engine damaging detonation otherwise rarely if ever seen with the stock unit.
Higher rev's are safer, and the idea of 3k-4k RPM's "wearing out" an engine may apply to your typical domestic V8, it doesn't apply to ours.
Tiny German 4-bangers are designed to spin at 4k all day long down the highway (like my wife's Bug).
Lower rev's carry with them a different concern. Say you are now lumbering along at 1,500rpm with your Vette trans and decide to speed up and floor it, you are now in an area of the curve and with that load susceptible to engine damaging detonation otherwise rarely if ever seen with the stock unit.
Higher rev's are safer, and the idea of 3k-4k RPM's "wearing out" an engine may apply to your typical domestic V8, it doesn't apply to ours.
06-18-2018, 03:22 PM
#5
I would say being at 1800 rpm at 90 is very nice... But if the car isn't really designed for it...
06-18-2018, 03:46 PM
#6
Three Wheelin'
Thread Starter
I would say being at 1800 rpm at 90 is very nice... But if the car isn't really designed for it...
06-18-2018, 04:04 PM
#7
Drifting
I have had the 2.2 rear put in my gts when the engine was done and at 80 mph I am now at 2400 rpm ish and the sound of 3k is not there at all...love the new rear end.....would NOT switch to a 6 speed, I love the auto and we also have an 01 yellow vette convertible 6 speed and 2010 vette gs 6 speed and I can tell you shifting gets to be a pain on any car and no my old knees are fine.........just my 0.02 cents
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06-18-2018, 04:18 PM
#8
Rennlist Member
lets not forget that Andy's GTS^^is also a GB storker with more tq/hp than a stock GTS or GT in your case. I have a C5 Z06 conversion in Just Peachy with approx 550hp. Would advise to use this trans/diff set up in cars with a minimum of 400hp. Stock 928's especially OB's just don't have the power on tap to make this switch worthwhile IMHO. This mod can also relate to your driving style, location, and speed limits along with how much time is spent on highway driving. Many of TX highways are marked 75 and 85mph with little elevation change...makes a difference 
T
T
Last edited by 77tony; 06-18-2018 at 06:14 PM.
06-18-2018, 04:33 PM
#9
Three Wheelin'
Thread Starter
Would advise to use this trans/diff set up in cars with a minimum of 400hp. Stock 928's especially OB's just don't have the power on tap to make this switch worthwhile IMHO.
06-18-2018, 05:08 PM
#10
06-18-2018, 07:04 PM
#12
Rennlist Member
Z06 1st gear - 2.66
Z06 2nd gear - 1.78
Z06 3rd gear - 1.30
Z06 4th gear - 1.00
Z06 5th gear - 0.74
Z06 6th gear - 0.50
Last edited by 77tony; 06-18-2018 at 10:57 PM.
06-18-2018, 07:10 PM
#13
Three Wheelin'
Thread Starter
Like has been said^^you can swap in a taller final drive ratio that may be right for you. Will also save plenty of time, $$$ by keeping it Porsche's and that's not a bad thing...especially for re-sale down the road.02 T
06-18-2018, 07:50 PM
#14
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Last edited by Bigfoot928; 08-02-2020 at 10:52 AM.
06-18-2018, 08:03 PM
#15
Three Wheelin'
Thread Starter
I had both the 2.20 and the 2.73 in the same car and it made a huge difference
so I don't think a gear swap is an option
but the way the rear cross member is modified, it uses all of the factory mount points and the inner mount points for the cross member go through the outer part and the inner part on both sides. I'm good with the design.
