RV cam, TBI and low vacuum? (1 Viewer)

[propilot]

I have been speaking with the folks at MAF about their engine kits and more specifically their RV cams. I am going to overhaul a 2F that I am getting a sweet deal on from 3_puppies. Thanks Paul! My plan is to install a TBI kit from Affordable Fuel Injection. The guys are telling me that I should stick to a stock grind cam instead of an rv cam. Their reasoning is that the TBI is very sensitive to vacuum and that I would see a significant drop in vacuum with the RV cam. I have read many posts, including Trollholes, and have not seen anything written about a drop in vacuum. Can someone help me put this issue to rest! Will installing an RV cam truly result in a significant enough loss of vacuum to impact the operation of the TBI system?

 

[Downey]

While I am in agreement with what Affordable Fuel Injection told you, and a higher lift Cam does put vacuum down in the 11 to 12 inch area, I have also read post here on Mud where there are some who believe they have solved the low vacuum problem by changing the MAP sensor. My only experience is that we were not able to change MAP sensors because the ECU's were also sensitive to incorrect MAP sensors---heck, I don't know what these guys are doing???
BUYER BEWARE---If Affordable is trying to sell you a system that does not include a VSS, or circuitry for a VSS, you'd better have alittle "come to Jesus" talk with me before buying!!!!!

 

[propilot]

Thanks Jim!
It wasn't AFI telling me not to use the RV cam, but rather the folks at MAF. I asked the guys at AFI and they can supply the VSS if I choose to use it. I have also read multiple threads here saying that the VSS is not needed. More questions i guess!!

 

[Downey]

My guess is the guys who think they don't need a VSS have a vehicle that "might" run ok, but they have no clue how smooth (good drivability) their vehicle could or should be. I have no problem with the guys who discover later on that they need a VSS and call me for one. I have a major problem with the Merchant who told you that you don't need one, so they removed the circuitry and wiring that allows you to use one after you find out that you really do need one!!!!!!!!!