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Registered User
Join Date: Oct 2007
Posts: 11
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Does a stock 930 have a rev limiter?
I've got an 86 930 completely stock, I've been autocrossing it and have had it up to 7000 rpm's about twice a run and have still not hit the rev limiter if there is in fact one. I usually run in first gear for the whole run and run between 3000 and 7000 rpm's, will these high rpm ranges damage the motor?
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Registered User
Join Date: Jun 2006
Posts: 295
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I have a rev limting rotor in the distributor, I believe they all do. It will cut out around 6800-7000 (according to the tach). I try to avoid hitting it though. It will happen very rarely, maybe a 2nd gear wheel spin or hard uphill 2nd gear pass (once).
If you are running 7K often, you are heading for some BIG repair bills. JMHO
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1987 930 - K27 7200 / DAS Full Cage / Blownsix Intercooler / BB Headers / Zork Tube / Tial 46mm / Adjustable WUR / RPM Activated Solenoid / Open Element Air Intake / Smart Racing 27mm Sways / 24 and 33mm Torsion Bars / Adj. Spring Plates / Wevo Strut Brace / Monoballs / Tow Hooks / Oil Cooler Scoop / Brey Krauss Harness Truss / Race Seats / XD-16 AFR Guage/ 17" Kodiak Racing Whees and Nitto NT-01 255/315s Last edited by F350Lawman; 10-22-2007 at 11:04 PM.. |
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resident samsquamch
Join Date: Oct 2005
Location: Cooterville, Cackalacky
Posts: 6,815
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I have my crank-fired ECU (Electromotive XDi) rev limiter set to 6,500 RPMs.
Honestly, I'm not sure if the stock dizzy and/or CDI box have a rev limiter. I know that the MSD 6AL CDI box (a common replacement when the Bosch unit goes down) has a rev-limiting feature. Back when my '87 was bone stock, I was accelerating hard from second to third, and before I could make the shift, the crappy OEM rubber centered clutch disc disintegrated, and the tach needle went all the way as the engine lost it's connection to the tranny and just free-revved! If you intend on seeing regular high RPM exchanges (especially if extended), at a minimum you'll need ARP rod bolts. The stock rod bolts have been commonly called "cheese". On a more track oriented engine (not sure if that applies to Auto X), race valve springs and retainers are a common change. Obviously, the rod bolts can be changed without having to split the crankcase, but while you've got the engine out and in pieces, terrible urges take over, and you become a human avalanche tumbling down a slippery slope.
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-jeff back in the saddle: '95 993 - just another black C2 *SOLD*: '87 930 GP White - heroin would have been a cheaper addiction... "Ladies and Gentlemen, from Boston Massachusetts, we are Morphine, at your service..." - Mark Sandman (RIP ![]() |
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resident samsquamch
Join Date: Oct 2005
Location: Cooterville, Cackalacky
Posts: 6,815
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For the occasional and typical short burst, or the owner manual advised spirited run, you should be fine. What I described above, in my other post, is more of a regular and extended scenario...
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-jeff back in the saddle: '95 993 - just another black C2 *SOLD*: '87 930 GP White - heroin would have been a cheaper addiction... "Ladies and Gentlemen, from Boston Massachusetts, we are Morphine, at your service..." - Mark Sandman (RIP ![]() Last edited by sand_man; 10-23-2007 at 05:44 AM.. |
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sudo apt-get purge 930
Join Date: Jul 2006
Location: Brandon, FL
Posts: 4,840
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Don't bet on it though, the rev limiting rotor can easily be replaced with a non rev limiting one.
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Mark 1979 930 Euro ***GONE AND DON'T MISS IT AT ALL*** "Worrying about depreciation on your car and keeping mileage down is like not ****ing your girlfriend so her next boyfriend finds her more appealing" --clutch-monkey |
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A fellow Pelacanite
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When changing to an MSD the stock rev limiting rotor has to be replaced with a non limiting one as it can overheat & burn out.
The problem with high rpm is the stock rod bolts as Sandman suggested. Rev limiting. ![]()
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1981 UK 930. G50/01 shortened, 964 3.8RS Fibreglass Body Kit, 18" Alloys 8.5" F & 10" R, 225's F & 285's R, Special Colour Metallic Blue Paint, FIA Sparco Evo's, A/C and Air Pump removed, Electronic Boost Controller, GHL Headers, Tial46 WG. Fitting - New service kit. Needs Fitting - Innovate XD-16 Kit, Kokeln IC. Stephen's K27 HFS, EVO Intake Assy & his Modded USA Fuel Head. 1983 UK 911 3.2 Carrera Sport Coupe. Black, Black Leather with Red Piping, Black Alloy Gear Knob, K&N Air Filter Element, Turbo Tie rods. Needs Fitting - K&N CO Sensor, Round A/F Dial Gauge, Factory Short Shift Kit. http://www.danasoft.com/sig/Iamnotanumber.jpg |
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Registered
Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 3,535
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Quote:
+1 on the ARP versus factory rod bolts. sand_man's spot on there. However, discussion on the engine rebuilding forum indicates that a stretch gauge is vastly preferred over torque or angle measurement methods, for accuracy. And you would have to split the case for that... Also probably worth noting that the Turbo Carrera owner's handbook has a specific warning: Quote:
I know it's Auto-X and you're trying to save a shift, but 7,000? Power's falling off a cliff on the stock motor by then, surely?
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'77 S with '78 930 power and a few other things. |
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Registered
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It's been a few years, but I vaguely remember hitting my rev limiter during an autox at about 7200 rpm.
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2014 Cayman S 2011 Cayenne Turbo 1979 930 (475 rwhp at 0.95 bar) |
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Registered
Join Date: Aug 2005
Location: Michigan
Posts: 3,337
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I would say yes that a stock 930 has a rev limiter. It's controlled by the CDI and not by the rotor.
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Bill |
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Registered User
Join Date: Jul 2006
Location: S. Florida
Posts: 7,289
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The CDI cuts out at 7200rpm and when it comes back on large flames come out the exhaust...
...pretty dramatic orange flash of light in the rear view mirror at night. |
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A fellow Pelacanite
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Woudl it matter how many wires the CDI has or did they all cut?
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1981 UK 930. G50/01 shortened, 964 3.8RS Fibreglass Body Kit, 18" Alloys 8.5" F & 10" R, 225's F & 285's R, Special Colour Metallic Blue Paint, FIA Sparco Evo's, A/C and Air Pump removed, Electronic Boost Controller, GHL Headers, Tial46 WG. Fitting - New service kit. Needs Fitting - Innovate XD-16 Kit, Kokeln IC. Stephen's K27 HFS, EVO Intake Assy & his Modded USA Fuel Head. 1983 UK 911 3.2 Carrera Sport Coupe. Black, Black Leather with Red Piping, Black Alloy Gear Knob, K&N Air Filter Element, Turbo Tie rods. Needs Fitting - K&N CO Sensor, Round A/F Dial Gauge, Factory Short Shift Kit. http://www.danasoft.com/sig/Iamnotanumber.jpg |
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Registered User
Join Date: Jul 2006
Location: S. Florida
Posts: 7,289
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Mine has a permatune that was in it when I got the car so I don't know...
I did hit a rev limiter accidentally while accelerating in first once at night as I described and my overboost switch is not hooked up so it wasn't that. I'm not sure if it was 7000 or 7200rpms where the ignition cut out... it happens too fast. I've read it is 7200rpm. I should add, mines and '87 930 and it does not have a rev limiting rotor. It does have B&B headers and single out muffler, K27 7200, 1 bar spring in origonal wastegate, Garretson halfbay intercooler and Powerhaus group B cams that are probably timed later than I like for a street car and DP935 air dam with large B&B front center oil cooler. Powerband is 4500rpm to 7200rpm with no let up. All that was in it when I got it. I have a new K27 HFS sitting here waiting to go in along with Andial SC330 cams, new rockers, and a Tial copy wastegate. Last edited by JFairman; 10-25-2007 at 05:21 PM.. Reason: more information |
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Registered
Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 3,535
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Quote:
My '78 distributor didn't have a rev-limiting rotor - because the '78 CDI boxes do the rev limiter thing. Apparently. See any potential danger here with a 915 box in stop-go traffic that suddenly clears after two miles of crawling? That rebuild 1,000 miles later cost me as much as it did to buy the car. I have a rev-limiting rotor now, you can take that to the bank. It cuts off kinda high for my taste - but I'm running ARP rod bolts these days...
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'77 S with '78 930 power and a few other things. |
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A fellow Pelacanite
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Ddi you break the tranny and the engine all in one go ?
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1981 UK 930. G50/01 shortened, 964 3.8RS Fibreglass Body Kit, 18" Alloys 8.5" F & 10" R, 225's F & 285's R, Special Colour Metallic Blue Paint, FIA Sparco Evo's, A/C and Air Pump removed, Electronic Boost Controller, GHL Headers, Tial46 WG. Fitting - New service kit. Needs Fitting - Innovate XD-16 Kit, Kokeln IC. Stephen's K27 HFS, EVO Intake Assy & his Modded USA Fuel Head. 1983 UK 911 3.2 Carrera Sport Coupe. Black, Black Leather with Red Piping, Black Alloy Gear Knob, K&N Air Filter Element, Turbo Tie rods. Needs Fitting - K&N CO Sensor, Round A/F Dial Gauge, Factory Short Shift Kit. http://www.danasoft.com/sig/Iamnotanumber.jpg |
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Registered
Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 3,535
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Didn't break the tranny as such, but when it was opened to be refreshed and have an LSD and some WEVO bits fitted, it was found to have pre-existing issues from a long hard life and prior rebuilds (it was likely the original box) and was pretty much a lost cause - especially considering a mag-cased 915 wasn't an ideal choice anyway.
So Mike (MBEngineering) built up an alu-cased 915 he tweaked to suit the application.
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'77 S with '78 930 power and a few other things. |
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A fellow Pelacanite
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Im guessing you could see the two shafts were trying to get away from each other?
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1981 UK 930. G50/01 shortened, 964 3.8RS Fibreglass Body Kit, 18" Alloys 8.5" F & 10" R, 225's F & 285's R, Special Colour Metallic Blue Paint, FIA Sparco Evo's, A/C and Air Pump removed, Electronic Boost Controller, GHL Headers, Tial46 WG. Fitting - New service kit. Needs Fitting - Innovate XD-16 Kit, Kokeln IC. Stephen's K27 HFS, EVO Intake Assy & his Modded USA Fuel Head. 1983 UK 911 3.2 Carrera Sport Coupe. Black, Black Leather with Red Piping, Black Alloy Gear Knob, K&N Air Filter Element, Turbo Tie rods. Needs Fitting - K&N CO Sensor, Round A/F Dial Gauge, Factory Short Shift Kit. http://www.danasoft.com/sig/Iamnotanumber.jpg |
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Registered
Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 3,535
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Quote:
So I got a WEVO bearing retainer and a WEVO billet diff cover from our host (who can special-order anything from any of their regular suppliers even if not in the PP catalog, you just need to provide the part #), and Mike Bainbridge opened that puppy up. There were also no dog teeth(? think that's what they're called) left on 1st, which explained why speed-matching and double-declutching didn't help one jot trying to shift into 1st when moving, and no bits of metal in the case - it probably had happened a long time ago. Box had been gone through once or twice before, most likely, Mike found some non-factory parts in there... The odo shows 237,000 the car was odo-exempt in WA state and it wasn't working when the PO got the car... The 5th gearset was an interesting mid-blue colour. Figured that oil slosh under boost on the track probably accounted for that - or maybe it got run out of oil a decade or two ago, who knows? Given that it was a mag case and that so much of it was distressed, sourced a '86 alu-cased 915 with an oil cooler in need of a fettling and fitted an internal spray bar kit, WEVO bearing retainer, 65/40 LSD and tweaked the ratios (taller 2nd and 5th). Couldnt' use the WEVO diff cover, because the factory oil pump fits under there, but the late, factory alu cover is much stronger than the early mag case part anyway. It would have been nice to use the WEVO part with the 930 bearing though...
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'77 S with '78 930 power and a few other things. |
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A fellow Pelacanite
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Sounds good now. Not sure why you wanted a higher 2nd though. 1st to 2nd spacing seems fine in my 3.2 carrera, not sure I would want them further apart.
From what I can see in my '83 915 the side cover seems fine & the opposing shafts would seem to be the problem. My stock retaining plate came loose... What would be good in that box is if a pump was strong enough to pull any loose dog teeth into a filter and keep them there until the box is rebuilt. I wonder if the swarf from the dog teeth damaged a bearing or two of mine. Since my rebuild so far so good using the Wevo retainer & K-nuts.
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1981 UK 930. G50/01 shortened, 964 3.8RS Fibreglass Body Kit, 18" Alloys 8.5" F & 10" R, 225's F & 285's R, Special Colour Metallic Blue Paint, FIA Sparco Evo's, A/C and Air Pump removed, Electronic Boost Controller, GHL Headers, Tial46 WG. Fitting - New service kit. Needs Fitting - Innovate XD-16 Kit, Kokeln IC. Stephen's K27 HFS, EVO Intake Assy & his Modded USA Fuel Head. 1983 UK 911 3.2 Carrera Sport Coupe. Black, Black Leather with Red Piping, Black Alloy Gear Knob, K&N Air Filter Element, Turbo Tie rods. Needs Fitting - K&N CO Sensor, Round A/F Dial Gauge, Factory Short Shift Kit. http://www.danasoft.com/sig/Iamnotanumber.jpg |
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OFF THE BOOST PIPE NOW...
Join Date: Oct 2003
Location: Mount Pleasant, South Carolina
Posts: 8,663
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My 87 didn't appear to have a rev limiter any where (dizzy or CDI), but maybe I never took it to 7200? Now that I have my MSD6AL, I have my shift light set at 6000 and the rev limiter set to 6400.
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Registered
Join Date: Oct 2006
Location: Chas, SC
Posts: 1,088
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According to the wiring diagrams for the 86, there is a speed sensor under the drivers seat, that shuts off the pumps just over 7k.
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Tim 1986 930 Gone:71,2,4 914's, 70T, 71T(RS),77S |
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