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Registered
Join Date: Nov 2003
Location: Bay Area, CA
Posts: 1,072
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3.6 V-ram swap engine spec questions:
I'm trying to finalize the spec on a V-ram motor I’ll order from Steve Timmins. I’d appreciate it you guys could offer your advice before I drop the cash (this week?). I’ve got planned:
Base motor: 35k mile US spec V-ram motor. Exhaust :TRG 1 7/8” coated headers with Coast 4.5” x 17” mufflers. Drive block removal/ chip. K&N filter. I would also like to raise the rev limit for the autocross, ideally finding another 500-1000 rpm. Any idea where the rev limit moves to with: Aftermarket valve springs? Aftermarket rod end bolts? Finally, what can be expected (cost, tq, power) if I were to spring for some port work? Are these the right things to be thinking on, and is there anything else I should be doing? 50% AX, 40% Track, 10% street. 7/32 915 transmission. I found some good posts on some of this stuff from Bill Verberg and others, but a lot of it was 3 years old. Suggestions on any or all of these would be appreciated. Thanks for the help. |
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Join Date: Jul 2002
Location: Washington state
Posts: 893
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Check with Mike Zois (mikez I think). He's on the 914 club too.
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'80 SC |
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Nothing has changed
for an extra 500 -1000 use Raceware or ARP rod bolts stock rods, RS intake valves SS(Cup) cams, 964 cam sprockets, for street hyd lifters are still ok, for extensive track go to the mech. The headers aree a little big for street use, stock springes keeper etc are still good for the extra 1k of revs, beyond that AASCo are probably the way to go Talk to Steve he has a very good handle on what works. The port work is where there are some big #s both in performance and $$, best to have someone w/ extensive experience do it. I hate to pay for some one elses education. I would go w/ an 8:31 r/p, lsd w/ some shorter 3,4,5 gears and tires ~25 - 25.5" tall max
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Bill Verburg '76 Carrera 3.6RS(nee C3/hotrod), '95 993RS/CS(clone) | Pelican Home |Rennlist Wheels |Rennlist Brakes | |
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Join Date: Nov 2003
Location: Bay Area, CA
Posts: 1,072
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Thanks Bill, I hoped you'd reply.
I am talking to Steve a lot, and he is saying one thing different than everything I have read here: He feels the 993 rod bolts are a major improvement over the 964 and previous rod bolts, and that they don't need to be changed as long as you're not going for higher revs than I am aiming at. I don't want to start an argument, but this is obviously a pretty critical point. How do we know they need to be changed? So who would you suggest if I was going to have the ports done? You're thinking I'll break the 7:31 R&P? My 2nd gear is about perfect for the AX with the 7:31 and a higher rev limit. It's taller than I'd like with the 8:31. I already have the short 3,4 and 5 gears and LSD...
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69 w 997 GT3 3.6L |
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The rod bolt thing may be true or not, I don't know. I was taking mine down to the crank anyway and new head studs, rod bolts, chains, sprockets etc was cheap insurance in my mind.
Steve Weiner or EBS or Dawe for ports I am sure there are other good choices as well for ports The 7:31 is far weaker and not at all desireable w/ the torque curve of the 3.6, 2nd gear w/ what engine and other drive train components? If you really want more drive use the 8:31 w/ short gears and ~24.5 - 25" tire
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Bill Verburg '76 Carrera 3.6RS(nee C3/hotrod), '95 993RS/CS(clone) | Pelican Home |Rennlist Wheels |Rennlist Brakes | |
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I want to be able to hit about 70 mph at the very top of 2nd- this should mean that on any normal AX course I will be able to drive the whole thing in 2nd. Previously with my 3.2 I would hit the limiter at 64 mph, and this was often a few mph too low. With my 245/50 16s, 7:31 and 2nd gear I would hit 72 mph with a 7500 rpm redline, and still be at 2600 rpm when pulling out of a 25 mph corner- good enough torque with the VRam.
The smallest tires I see in that size are 245/45/16, which with an 8:31 would gear me out at 79 @ 7500 rpm, ie 10%+ less torque through the rev range. Hence the strong desire to use the 7:31. I guess I could do a different 2nd (?), but that would really mean doing at least 3rd and 4th too...
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69 w 997 GT3 3.6L |
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I was thing more along the lines of a 255/40 or 265/35 x17
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Bill Verburg '76 Carrera 3.6RS(nee C3/hotrod), '95 993RS/CS(clone) | Pelican Home |Rennlist Wheels |Rennlist Brakes | |
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RETIRED
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Sorry...I have a pre V-ram....
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1983/3.6, backdate to long hood 2012 ML350 3.0 Turbo Diesel |
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Montana 911
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Mike...did you guys ever do a NBD chip for the 993 (Non-Vario)?
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H.D. Smith 2009 997.2 S 3.8 PDK 2019 Ford Ranger Lariat FX4 Baby Raptor 2019 Can Am Renegade 1000R XC 2020 Yamaha YFZ450R |
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Join Date: Nov 2003
Location: Bay Area, CA
Posts: 1,072
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Bill- I can't find a comp tire in 265/35 x17. The 255/40 x17 is the same or bigger than the 245/45 x16, so it wouldn't help the gearing issue. I'll search and perhaps post a new topic regarding the 7:31 r&p torque handeling ability and failure mode. Perhaps Weviod or someone has some good data.
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69 w 997 GT3 3.6L |
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RETIRED
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Quote:
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1983/3.6, backdate to long hood 2012 ML350 3.0 Turbo Diesel |
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ok Mike...just wondering as the 964 chip seems to work very well for BBII
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H.D. Smith 2009 997.2 S 3.8 PDK 2019 Ford Ranger Lariat FX4 Baby Raptor 2019 Can Am Renegade 1000R XC 2020 Yamaha YFZ450R |
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Registered
Join Date: Dec 2003
Location: Peru, Indiana
Posts: 455
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Hi, just to chime in. I'm interested in the 915 issue. I'm doing the same with a 3.6 conversion hopefully yet this year and wondered about the 7/3/1 vs 8/3/1 w-lsd. I'm running 15" tires. I'll follow this thread.
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1977 911 with major upgrades! |
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Bill Verburg '76 Carrera 3.6RS(nee C3/hotrod), '95 993RS/CS(clone) | Pelican Home |Rennlist Wheels |Rennlist Brakes | |
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Just found your other post, I see that you did search.
If you are serious I would sit down and do a spreadsheet, using 8:31 and the tires of your choice, those 2 items are the biggest constraints on what you can do. I am sure that an appropriate gear cluster can be put together, it won't be cheap though.
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Bill Verburg '76 Carrera 3.6RS(nee C3/hotrod), '95 993RS/CS(clone) | Pelican Home |Rennlist Wheels |Rennlist Brakes | |
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