Vacuum or no

Barry Jackson · 12-18-2002, 07:40 AM

How does running a distributor with no vac advance work for you all who are driving street/strip cars? Is it difficult on the street?
Thanks,

PKRWUD · 12-18-2002, 10:21 AM

Vacuum advance isn't needed for racing because the engine is always running at higher rpms, but a sterrt driven car spends the majority of it's life under 3000 rpms, where the vacuum advance is helpful. Try it with and without, and see what you like better. It's just a hose.

crazypete · 12-18-2002, 12:47 PM

I'm running without it for the moment and the engine definatley seems a bit more lumpy and a bit more hesitant when transitioning into low rpm, high load situations. It's more of a slightly annoying feeling than a real drivability problem, though. Gas milage drop like 3 points though, so be careful

Barry Jackson · 12-18-2002, 12:58 PM

Thanks for the replies. Could you give me an idea as to wiring on your MSD? Your not running the stock module, just the MSD box and distributor? With the duraspark module there are 4 wires out of the box, I am concerned as to getting the start, run etc. wires correct. Did you look at the distributors with build in module and coil?
Thanks,

red82gt · 12-18-2002, 03:05 PM

I just used one of the wires from my duraspark harness (I can't remeber off hand which one) and then modified my duraspark distributor harness and attached it to the purple and green wires going to the MSD box. Look on the MSD website, you can download the instruction manuals. Cleans up the underhood wiring a bunch when you get rid of the duraspark box.
About the vacuum advance, my car lost a bit of fuel mileage without it and since the vacuum advance hasn't caused any problems, I decided to keep it, I do 99% of my driving not at WOT so every MPG I can get, I'll take. As I said in my PM, I've only got mine adjusted to advance the timing by 8* max.

crazypete · 12-20-2002, 12:11 PM

Well, if you have the msd box, all you need is the distributor. The black wire from the distributor, I just looped back and grounded to the dist frame, the purple goes to msd purple and the blue goes to msd ...green is it?

12-18-2002, 07:40 AM	#1
Barry Jackson Registered Member Join Date: Oct 1998 Location: Pitts. Pa. USA Posts: 61	Vacuum or no How does running a distributor with no vac advance work for you all who are driving street/strip cars? Is it difficult on the street? Thanks, __________________ 87 LX, 74 351W, performer plus intake, holley 750, vac sec., 78 prim. 80 sec., 50 pump: Wolverine cam 292-512, windsor heads, ported 3 angle valve, 4:10 rear, AOD, Lentech valve body w/ 10'' converter. No time slips yet!

12-18-2002, 10:21 AM	#2
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Vacuum advance isn't needed for racing because the engine is always running at higher rpms, but a sterrt driven car spends the majority of it's life under 3000 rpms, where the vacuum advance is helpful. Try it with and without, and see what you like better. It's just a hose. __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

12-18-2002, 12:47 PM	#3
crazypete Registered Member Join Date: Sep 2002 Location: Boston Posts: 592	I'm running without it for the moment and the engine definatley seems a bit more lumpy and a bit more hesitant when transitioning into low rpm, high load situations. It's more of a slightly annoying feeling than a real drivability problem, though. Gas milage drop like 3 points though, so be careful __________________ 91 GT Carb conversion, holley 600 double pumper, edelbrock performer intake, FMS "C" drop springs, march 1000 underdrive pullies, crane 1.7 roller rockers, GT-40P headers, bassani x pipe, american thunder catback, FMS 4.56's, msd aL6, trunkmount battery, A/C eliminator kit, 3000 stall tci streetfighter, AOD with transgo kit, A+ servo, 300M hardened lockup shaft, kevlar bands and 28,000 gvw trans cooler, 3 core radiator, 300 lbs stripped with a full interior

12-18-2002, 12:58 PM	#4
Barry Jackson Registered Member Join Date: Oct 1998 Location: Pitts. Pa. USA Posts: 61	vacuum or no Thanks for the replies. Could you give me an idea as to wiring on your MSD? Your not running the stock module, just the MSD box and distributor? With the duraspark module there are 4 wires out of the box, I am concerned as to getting the start, run etc. wires correct. Did you look at the distributors with build in module and coil? Thanks, __________________ 87 LX, 74 351W, performer plus intake, holley 750, vac sec., 78 prim. 80 sec., 50 pump: Wolverine cam 292-512, windsor heads, ported 3 angle valve, 4:10 rear, AOD, Lentech valve body w/ 10'' converter. No time slips yet!

12-20-2002, 12:11 PM	#6
crazypete Registered Member Join Date: Sep 2002 Location: Boston Posts: 592	Well, if you have the msd box, all you need is the distributor. The black wire from the distributor, I just looped back and grounded to the dist frame, the purple goes to msd purple and the blue goes to msd ...green is it? __________________ 91 GT Carb conversion, holley 600 double pumper, edelbrock performer intake, FMS "C" drop springs, march 1000 underdrive pullies, crane 1.7 roller rockers, GT-40P headers, bassani x pipe, american thunder catback, FMS 4.56's, msd aL6, trunkmount battery, A/C eliminator kit, 3000 stall tci streetfighter, AOD with transgo kit, A+ servo, 300M hardened lockup shaft, kevlar bands and 28,000 gvw trans cooler, 3 core radiator, 300 lbs stripped with a full interior

12-18-2002, 03:05 PM	#5
red82gt Sober voice of Reason Join Date: Nov 1998 Location: Kelowna, B.C., Canada Posts: 1,514	I just used one of the wires from my duraspark harness (I can't remeber off hand which one) and then modified my duraspark distributor harness and attached it to the purple and green wires going to the MSD box. Look on the MSD website, you can download the instruction manuals. Cleans up the underhood wiring a bunch when you get rid of the duraspark box. About the vacuum advance, my car lost a bit of fuel mileage without it and since the vacuum advance hasn't caused any problems, I decided to keep it, I do 99% of my driving not at WOT so every MPG I can get, I'll take. As I said in my PM, I've only got mine adjusted to advance the timing by 8* max.

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