http://store.summitracing.com/partdetail.asp?autofilter=1&part=SSB%2D28146&N=700+4294922533+115&autoview=sku

Thinking about getting one....unless the hydroboosts are even more efficient....

Pump works very well, when it decides to work. I've had the pressure switch hang up a few times recently. Very hairy situation when you go for the brakes and the pedal is hard as a rock. I get out of the car and tap the switch a few times and pump kicks on. I will call them to get it warranteed next week. Maybe I just got a defective one?

Hhhmm.....does the pump solely provide the vacuum?

There's another model on Summit's website, a little more expensive, and they say the pump ties in with the engine's intake and monitors the engine vacuum and only operates when the switch deems the vacuum from the engine is too low...

Another alternative if your budget allows and especially like me do not have or want power steering needed to drive Hydro Boost ( this system was suggested to me by hydro boost tech )

Check out " ABS Hi Power Vacuum Electric System "..........not much talk about this system here but works awesome on all types of brakes and you can mount it anywhere you want .....mine is hidden under car on frame rail .now no issues with clearance at Valve cover .clean engine compartment and most important very reliable .....has electric motor AND an accumulator resorvoir for 25 pedal pumps if you ever lose electic power ....... after one season on my 4 wheel drum car .yes drum car!!! ( was original power brake car but no vacuum or room for booster with new motor) I am very pleased .have a friend you bot a system after me for his 4 wheel disc truck street rod loves it ................. Not sure but I beleive this a common system on hi end German cars with turbo's ......never had an issue very smooth application of power increase on brake pedal and quiet ....pump only comes on when resovoir needs filling
FWIW

I had one in my car worked well as long as you only used the brakes once. The recharge time was about 10-15 seconds so you may contemplate adding external storage for more repeditive breaking. I pulled it off and went to a manual master cylinder and couldn't be happier. I had a dual 8" booster since I needed the clearence for the tall valve covers on my tall deck big block.

We use a vacuum system from a turbo Volvo car from the mid-80's. It's a good sized pump and a large reservior that's isolated and teed into the manifold. You get about 3 good apps before you run low on vacuum, unless the manifold vacuum goes high enough, which usually happens on hard decel.

I also am using a vacume pump w/SSB vacume switch, I also thought the switch was not working correctly.
It wasn't the switch, it was the relay going bad.
Sometimes it would come on at 5" and run until it was 25", sometimes it would come on at 15", 18" 22" so I called SSB and got a replacement.
Still had the same problem?
I checked the vac. switch and it was good, then I checked the relay, not good.
I now have really good brakes, even with my 8" dual diafram booster.
T.C.