DIY OBD-1 Varioram Conversion Step by Step (More or less) - Page 2

slvr993 · 01-02-2009, 09:43 AM

Very nice! Now that you've driven the car is all the work worth it. Is there a noticable change in torque?

Jeff

Garth S · 01-02-2009, 09:45 AM

Excellent execution!

RallyJon · 01-02-2009, 12:10 PM

Well done! Thank you for the documentation.

travanx · 01-02-2009, 03:28 PM

Hows it feel?????

baron95993 · 01-02-2009, 04:14 PM

That is a great write up. My buddy just converted to a supercharger and gave me his intake system. I think I might do it after reading this. Thanks again great pics.

Baron

99three · 01-02-2009, 05:35 PM

Oh man!

North Coast Cab · 01-02-2009, 05:42 PM

Damn it! My engine rebuild is completely done, but still sitting on the engine stand. I have a v-ram intake in the basement and I decided not to do the upgrade. But now..........
Very nice job and thanks for the info.

chris walrod · 01-02-2009, 05:47 PM

Great work indeed! You have been speaking with a good friend of mine Gerry K. He is doing the same conversion now and really appreciates your insight!

jmarch · 01-02-2009, 06:02 PM

Thanks for the kind comments everyone. I have not dynoed the car either before or after so I can only describe the change in feel. However, note that in his book "Porsche 911 Story," Paul Frere claims the difference in torque at 4000 rpm is +60 Nm (44 lb/ft) for the v-ram engine. No doubt that this due in part to the slightly larger valves and different cam profiles in the later cars, but the majority of the increase comes from the improved ram effect offered by the v-ram. As we all know, peak tq and hp are only marginally improved.

The feel of the car confirms this. At part throttle and at less than 5K rpm, that car simply feels more responsive. Put another way, there's less need to downshift when street driving. At full throttle or high rpms the difference is minimal. This is why race car owners may find the improvements marginal. However, for those of us who use our cars on the street, the conversion is a distinct improvement.

As our modest friend Tal states, the beauty of this conversion is that it is it can be done with all Porsche parts. In effect, we updated our cars as Porsche did with the Euro OBD-1 cars. Also, I think there's very reasonable bang for the buck with the conversion. And improved torque curve with a +44 lb / ft imcrease at 4K rpm seems reasonable for less than $1500 (assuming you source a reasonably priced manifold and do the work yourself). Frankly, regearing the car (and perhaps even adding a LWF), will provide more noticeably results - but at a much great cost. (Of course, I'll be doing these later too)

One more benefit - I learned tons about my 993 doing conversion. Great fun.

jmarch · 01-02-2009, 06:05 PM

Quote:

Originally Posted by North Coast Cab

Damn it! My engine rebuild is completely done, but still sitting on the engine stand. I have a v-ram intake in the basement and I decided not to do the upgrade. But now..........
Very nice job and thanks for the info.

It's not too late! It would have been a lot easier to do the conversion with the engine out.

jmarch · 01-02-2009, 06:06 PM

Quote:

Originally Posted by chris walrod

Great work indeed! You have been speaking with a good friend of mine Gerry K. He is doing the same conversion now and really appreciates your insight!

Thanks Chris, I'm glad to help. Gerry is a nice guy.

North Coast Cab · 01-02-2009, 10:20 PM

FYI - there is a varioram intake on eBay for $600, seems like a goods price. There is also a varioram wiring harness for $699, and a DME for $1900 ouch.....but we now know how to get around it.

AOW162435 · 01-02-2009, 11:28 PM

Joe,
WOW! That's an amazing DIY and a fantatstic write-up. May your steed give you many, many trouble-free miles.

Andreas

Jeff96-993 · 01-03-2009, 06:41 PM

Quote:

Originally Posted by jmarch

You will need to run two wires from the ECU to the engine fuse box.... Carefully open the ECU 55 pin connector and splice into the #1 and #32 wires (the locations are numbered but hard to see – you may need a magnifying glass). FYI - #1 is used to control the resonance flap and #32 is used for the SAI. Next remove the engine fuse box cover and find the 21 pin connector. You can remove this connector by sliding the “drawer” to the side (the drawer lacks the connector in place). Connect ECU wire #1 with a BMW bullet connector to #18 in the 21 pin connector. Connect ECU wire #32 with the other BMW bullet connector to #4 in the 21 pin connector.

Is this how you avoid the SAI fault that triggers the MEL???? Would it work on a 1996 car???

I don't have the SAI fault yet, but if it's inevitable, I want as many options as possible to fix, and one of those options I hope is elimination of the system. If this is the way to do it I'd like to know.

C4S_fan · 01-03-2009, 07:48 PM

Wow - great work and a fantastic write-up!

01-02-2009, 09:43 AM	#16
slvr993 Addict Rennlist Member Join Date: May 2006 Location: West Chester PA Posts: 366	Very nice! Now that you've driven the car is all the work worth it. Is there a noticable change in torque? Jeff __________________ '95 993 Polar Silver

01-02-2009, 09:45 AM	#17
Garth S Addict Rennlist Member Join Date: Oct 2003 Location: Nova Scotia Posts: 6,482	Excellent execution! __________________ '96 993 C4S Midnight blue , Bilstein HD, M030 bars & turbo springs, FPB, SSK, wide ovals w. LPMM, 8"/11" 'hollows', Schnell brace '80 928 Copper brown 5-sp, Konis, euro S springs/brakes, CS wheels, S4 wing '88 928 Euro, Nougat brown, GTS rear, Konis, BBS .... sold ... '90 535i 5-sp black, Bilsteins/Dinan, 3-pc wheels, ..

01-02-2009, 03:28 PM	#19
travanx Addict Rennlist Member Join Date: Jun 2007 Location: Los Angeles Posts: 544	Hows it feel????? __________________ 993 Stolen from Glendale, CA 7-08-09 roughly 4am. Recaro Speed Seat, Wedge Engineering Bracket 18" Work Brombacher in Dark Gold/Polished Lip KW V3 Coilovers Stage1 Exhaust Mod with Pretty Tips FS: Stock Parts I still have from the 993 Civil Development Group

01-02-2009, 04:14 PM	#20
baron95993 Addict Rennlist Member Join Date: Feb 2007 Location: Tyler Texas Posts: 502	That is a great write up. My buddy just converted to a supercharger and gave me his intake system. I think I might do it after reading this. Thanks again great pics. Baron __________________ 1995 993 C2 Iris Blue/Cashmere 18 Light weight Carrera 5 spokes Lowered Eibach Springs Performance Chip Factory Xenon Headlamps 207,000 and going Strong

01-02-2009, 05:35 PM	#21
99three Addict Rennlist Member Join Date: Nov 2006 Location: Toronto Posts: 1,204	Oh man! __________________ Serf 96 993 Polar Silver - BBS RS-GT, Fabspeed 200 Cell Cats, Fabspeed Maxflow mufflers, Schnell Tips, Bilstein PSS9, Heated Factory Sport Seats, Carrera Cup Intake, Schnell Strut Brace, HID's, Clear corners, RS Shifter, RS Transmission mount, Gerts Protection Bar. DIY website: www.pcarworkshop.com

01-02-2009, 12:10 PM	#18
RallyJon Weathergirl Rennlist Member Join Date: Oct 2002 Location: SE PA Posts: 4,645	Well done! Thank you for the documentation. __________________ 02 996 C4S · 95 993 C4 · 911 RS look · STI · S4 · rally car

01-02-2009, 05:42 PM	#22
North Coast Cab Addict Rennlist Member Join Date: Nov 2005 Location: Cleveland Posts: 492	Damn it! My engine rebuild is completely done, but still sitting on the engine stand. I have a v-ram intake in the basement and I decided not to do the upgrade. But now.......... Very nice job and thanks for the info. __________________ '95 993 C2 RS Look '85 944 GTS1 #643 '85 944 #24 Alcohol Killer FOR SALE Past '84 911 Cab '76 911 Race - All Glass

01-02-2009, 05:47 PM	#23
chris walrod Guru Lifetime Rennlist Member Rennlist Small Business Sponsor Join Date: Aug 2001 Location: yorba linda, ca Posts: 13,714	Great work indeed! You have been speaking with a good friend of mine Gerry K. He is doing the same conversion now and really appreciates your insight! __________________ Is this a great place or what? Chris 97 993 twin http://www.swiftengineering.com/ Cool Video Latest FN News

01-02-2009, 06:02 PM	#24
jmarch Addict Rennlist Member Join Date: Feb 2004 Location: SF Bay Area and Seattle Posts: 1,079	Thanks for the kind comments everyone. I have not dynoed the car either before or after so I can only describe the change in feel. However, note that in his book "Porsche 911 Story," Paul Frere claims the difference in torque at 4000 rpm is +60 Nm (44 lb/ft) for the v-ram engine. No doubt that this due in part to the slightly larger valves and different cam profiles in the later cars, but the majority of the increase comes from the improved ram effect offered by the v-ram. As we all know, peak tq and hp are only marginally improved. The feel of the car confirms this. At part throttle and at less than 5K rpm, that car simply feels more responsive. Put another way, there's less need to downshift when street driving. At full throttle or high rpms the difference is minimal. This is why race car owners may find the improvements marginal. However, for those of us who use our cars on the street, the conversion is a distinct improvement. As our modest friend Tal states, the beauty of this conversion is that it is it can be done with all Porsche parts. In effect, we updated our cars as Porsche did with the Euro OBD-1 cars. Also, I think there's very reasonable bang for the buck with the conversion. And improved torque curve with a +44 lb / ft imcrease at 4K rpm seems reasonable for less than $1500 (assuming you source a reasonably priced manifold and do the work yourself). Frankly, regearing the car (and perhaps even adding a LWF), will provide more noticeably results - but at a much great cost. (Of course, I'll be doing these later too) One more benefit - I learned tons about my 993 doing conversion. Great fun. __________________ 1995 Porsche 993 - G50/31, RS Clutch/Flywheel, OBD-1 VRAM Conversion, ROW M030 springs/sways, Bilstein HDs, Techart Strut Brace, Softback Sport Seats, Litronics, OBC Retrofit, 996 3 Spoke Wheel/Leather Airbag, Basket Handle Delete, C2S Split Grill, Big Ovals, MY02 18" Wheels 1988 BMW 325IS - 215K mile daily driver 2001 BMW 530IA Sport - hers 2005 KTM 450EXC - More fun than all of the above VRAM Conversion DIY: http://forums.rennlist.com/rennforum...ferrerid=21390

01-02-2009, 10:20 PM	#27
North Coast Cab Addict Rennlist Member Join Date: Nov 2005 Location: Cleveland Posts: 492	FYI - there is a varioram intake on eBay for $600, seems like a goods price. There is also a varioram wiring harness for $699, and a DME for $1900 ouch.....but we now know how to get around it. __________________ '95 993 C2 RS Look '85 944 GTS1 #643 '85 944 #24 Alcohol Killer FOR SALE Past '84 911 Cab '76 911 Race - All Glass

01-02-2009, 11:28 PM	#28
AOW162435 Semper Mundus Rennlist Member Join Date: Jul 2005 Location: Ellicott City, MD Posts: 8,653	Joe, WOW! That's an amazing DIY and a fantatstic write-up. May your steed give you many, many trouble-free miles. Andreas __________________ 1995 993 Coupe Polar Silver - Black peapod-designs.com

01-03-2009, 07:48 PM	#30
C4S_fan Addict Rennlist Member Join Date: Jul 2004 Location: Seattle, WA Posts: 776	Wow - great work and a fantastic write-up! __________________ Dennis 1996 Polar Silver / Black C4S Love everything about it