968 Supercharger Kit Development
05-24-2011, 12:56 PM
#1081
Developer
Thread Starter
Did you tighten the belt during the weekend?
Plus, the belt wears down into a lower place in the grooves on the 6-rib side, and that will make it loose too.
Install a new belt. Drive it a bit, re-tension as needed.
05-24-2011, 01:51 PM
#1082
Yes belt tension is now a check everytime I go out, it is fine each time so no stretch, with maybe a 1/2 turn of the buckle after the run, just a belt slippage issue still with dust evident, but not as much as in the past, but a wear on the smooth side due the aggresive knurling.
The pulley is working, it is probably a driving issue, where you can feed the throttle on, or a quick mash of the pedal it gets caught out and spins, though momentarily.
I get good boost generally from 4000 and it will rev to the red line, but the boost guage gets hesitant at prolonged red line shifts, need to take an in car video of the gauges.
Yes the crank upgrde is there with the pulley mod, but non existant at the moment, Carl need`s comitted customers, plus the extra upgrdes involved with the crank upgrade, injectors, fuel pump, possible re-mapping, etc;
All in all, after 2 years I`m finally getting some extra power with as is, but crave more.
Speed is $$$, £££
Carl what size is the new pulley? Gone from 2.25" with the SII, to 2.30" semi knurled to this one. Would it be possible to get a fulley knurled and hardened 2.30" if the new one is slightly bigger.
However put me down as an interested customer for the crank pulley upgrade and lets hope more jump on board.
The pulley is working, it is probably a driving issue, where you can feed the throttle on, or a quick mash of the pedal it gets caught out and spins, though momentarily.
I get good boost generally from 4000 and it will rev to the red line, but the boost guage gets hesitant at prolonged red line shifts, need to take an in car video of the gauges.
Yes the crank upgrde is there with the pulley mod, but non existant at the moment, Carl need`s comitted customers, plus the extra upgrdes involved with the crank upgrade, injectors, fuel pump, possible re-mapping, etc;
All in all, after 2 years I`m finally getting some extra power with as is, but crave more.
Speed is $$$, £££
Carl what size is the new pulley? Gone from 2.25" with the SII, to 2.30" semi knurled to this one. Would it be possible to get a fulley knurled and hardened 2.30" if the new one is slightly bigger.
However put me down as an interested customer for the crank pulley upgrade and lets hope more jump on board.
Last edited by edz968s; 05-24-2011 at 02:46 PM.
05-24-2011, 10:07 PM
#1084
Developer
Thread Starter
Okay! With 3 confirmed buyers, I will order 5.
This is from Post 1066:
I will issue a PO to the machinist tomorrow for 5.
We would like 50% down now, and the balance when it ships. Call us, or email your order to carl@928motorsports.com and I will see that it gets to Gretchen for billing.
And THANK YOU!
This is from Post 1066:
Update on the Stage II kit Pulley Upgrade
The engineering on the new crank pulley for the 968 kit is finished, and I have my manufacturing bids.
If I order 5 of the crank pulleys, I can get them at $393.00 each. If I order 10 of them, I can get them for $315.00 each.
The new crank pulley is 6.125" in diameter, which will turn the impeller at 46,838 rpm at 6500 crank, when using a 2.55" SC pulley. There will be no belt slip in this combination.
Currently, 928MS Kit owners are running a 5.11" crank pulley and a 2.35" SC pulley to spin the impeller 42,402 rpm at 6500. Most report 5 psi of boost from this setup.
Experience with the 968 has shown us that a change 922 impeller rpm translates to 1 psi.
My best estimate of the boost made from the new Stage II crank pulley and a 2.55 SC pulley is 9-10 psi on an otherwise unmodified 968.
Be advised that I am certain the stock fuel system, even with our FMU installed, will not be able to fuel a 10 psi boost kit. Larger injectors will be needed, and quite possibly a larger pump or modern engine management system.
My question for the forum is: now that we know the price of the new crank pulley, how many want one?
The engineering on the new crank pulley for the 968 kit is finished, and I have my manufacturing bids.
If I order 5 of the crank pulleys, I can get them at $393.00 each. If I order 10 of them, I can get them for $315.00 each.
The new crank pulley is 6.125" in diameter, which will turn the impeller at 46,838 rpm at 6500 crank, when using a 2.55" SC pulley. There will be no belt slip in this combination.
Currently, 928MS Kit owners are running a 5.11" crank pulley and a 2.35" SC pulley to spin the impeller 42,402 rpm at 6500. Most report 5 psi of boost from this setup.
Experience with the 968 has shown us that a change 922 impeller rpm translates to 1 psi.
My best estimate of the boost made from the new Stage II crank pulley and a 2.55 SC pulley is 9-10 psi on an otherwise unmodified 968.
Be advised that I am certain the stock fuel system, even with our FMU installed, will not be able to fuel a 10 psi boost kit. Larger injectors will be needed, and quite possibly a larger pump or modern engine management system.
My question for the forum is: now that we know the price of the new crank pulley, how many want one?
We would like 50% down now, and the balance when it ships. Call us, or email your order to carl@928motorsports.com and I will see that it gets to Gretchen for billing.
And THANK YOU!
05-24-2011, 11:40 PM
#1086
Nordschleife Master
05-25-2011, 10:30 AM
#1087
Developer
Thread Starter
Tim, Mark and Ed - call or email gretchen today to place a 50% deposit.
Anybody else that wants a new crank pully made- do the same thing.
Call 920-485-0928
Email: gretchen@928motorsports.com
Anybody else that wants a new crank pully made- do the same thing.
Call 920-485-0928
Email: gretchen@928motorsports.com
05-25-2011, 12:47 PM
#1088
Nordschleife Master
Tim, Mark and Ed - call or email gretchen today to place a 50% deposit.
Anybody else that wants a new crank pully made- do the same thing.
Call 920-485-0928
Email: gretchen@928motorsports.com
Anybody else that wants a new crank pully made- do the same thing.
Call 920-485-0928
Email: gretchen@928motorsports.com
05-25-2011, 02:55 PM
#1089
Sorry but I am going to have to opt out of the crank pulley upgrade.
I could order one, but then what next?
Upgraded fuel pump, larger injectors, possible re-map, new head unit pulley and most probably an intercooler.
I don`t have the $$$ to invest more into the car at the present, so sorry will have to give a miss.
2 years ago I paid nearly $5000 for a stage 2 kit, which so far and more $$$ later has not got the 100-100hp promised.
I could just go on and on spending more money on it. so I`ve decided to stop with what I have and try to enjoy the car with what it has.
Perhaps later in the year and you have a crank pulley on the shelf and finances are glowing, then maybe I`ll restart the project upgrades, but until then and with, apologies I will have to say no and pull out of this upgrade.
I could order one, but then what next?
Upgraded fuel pump, larger injectors, possible re-map, new head unit pulley and most probably an intercooler.
I don`t have the $$$ to invest more into the car at the present, so sorry will have to give a miss.
2 years ago I paid nearly $5000 for a stage 2 kit, which so far and more $$$ later has not got the 100-100hp promised.
I could just go on and on spending more money on it. so I`ve decided to stop with what I have and try to enjoy the car with what it has.
Perhaps later in the year and you have a crank pulley on the shelf and finances are glowing, then maybe I`ll restart the project upgrades, but until then and with, apologies I will have to say no and pull out of this upgrade.
05-25-2011, 08:44 PM
#1090
Racer
Join Date: Oct 2003
Location: Palm Beach, FL / Hamburg, DE
Posts: 418
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Have not seen you post in this thread before, guess that means you are a new SC owner. Tell us about your car.
MN
05-26-2011, 11:50 AM
#1091
Developer
Thread Starter
Mark, welcome to the group, and thank you for your deposit on the new crank pulley.
Looking for one or two more.... I went ahead and placed my order, but would like at least 3 confirmed. Anyone? If you are going to Stage II later, this is the way to do it!
Looking for one or two more.... I went ahead and placed my order, but would like at least 3 confirmed. Anyone? If you are going to Stage II later, this is the way to do it!
05-26-2011, 01:39 PM
#1092
Racer
Join Date: Oct 2003
Location: Palm Beach, FL / Hamburg, DE
Posts: 418
Likes: 0
Received 9 Likes
on
9 Posts
Sorry but I am going to have to opt out of the crank pulley upgrade.
I could order one, but then what next?
Upgraded fuel pump, larger injectors, possible re-map, new head unit pulley and most probably an intercooler.
I don`t have the $$$ to invest more into the car at the present, so sorry will have to give a miss.
2 years ago I paid nearly $5000 for a stage 2 kit, which so far and more $$$ later has not got the 100-100hp promised.
I could just go on and on spending more money on it. so I`ve decided to stop with what I have and try to enjoy the car with what it has.
Perhaps later in the year and you have a crank pulley on the shelf and finances are glowing, then maybe I`ll restart the project upgrades, but until then and with, apologies I will have to say no and pull out of this upgrade.
I could order one, but then what next?
Upgraded fuel pump, larger injectors, possible re-map, new head unit pulley and most probably an intercooler.
I don`t have the $$$ to invest more into the car at the present, so sorry will have to give a miss.
2 years ago I paid nearly $5000 for a stage 2 kit, which so far and more $$$ later has not got the 100-100hp promised.
I could just go on and on spending more money on it. so I`ve decided to stop with what I have and try to enjoy the car with what it has.
Perhaps later in the year and you have a crank pulley on the shelf and finances are glowing, then maybe I`ll restart the project upgrades, but until then and with, apologies I will have to say no and pull out of this upgrade.
Who knows if and when a upgraded crank pulley will be available again (not knowing Carl's policy regarding one-off, custom order)?
MN
05-27-2011, 09:54 AM
#1093
Nordschleife Master
ETA on the pulleys?
06-06-2011, 04:36 PM
#1095
Ok.
I have just done a 400 mile round trip with some spirited driving
The fully knurled pulley is working, but it`s eating the outer/smooth face of the belt where it wraps over the head unit pulley and after the 400 miles was totally shot.
I still had constant and regular boost all the way to the red line, though only barely touching 5 each time.
I take it this pulley is a 2.55", but seems to be the downside, is a regular belt swap after 400-600 miles depending on the throttle application.
I think there maybe a solution to getting more wrap on the pulley and am going to look into this.
My thinking is a pulley similar and size to the extra alternator wrap pulley, but 6-ribbed and mounting it to the head unit through an existing bolt hole, aft of the s/c head one as it runs back to the crank anti clockwise.
Overall, I had a blast, literally, last weekend and the car flew, bit of a flat spot around 3500, but 4000, takes off, so a bit of fine tuning still needed
I have just done a 400 mile round trip with some spirited driving
The fully knurled pulley is working, but it`s eating the outer/smooth face of the belt where it wraps over the head unit pulley and after the 400 miles was totally shot.
I still had constant and regular boost all the way to the red line, though only barely touching 5 each time.
I take it this pulley is a 2.55", but seems to be the downside, is a regular belt swap after 400-600 miles depending on the throttle application.
I think there maybe a solution to getting more wrap on the pulley and am going to look into this.
My thinking is a pulley similar and size to the extra alternator wrap pulley, but 6-ribbed and mounting it to the head unit through an existing bolt hole, aft of the s/c head one as it runs back to the crank anti clockwise.
Overall, I had a blast, literally, last weekend and the car flew, bit of a flat spot around 3500, but 4000, takes off, so a bit of fine tuning still needed