Competition twins and boost gauges????

[LNeshem]

I am building a set of twins, running an HX35/40 hybrid on top and a B2 on bottom. I am trying to find out what kinda boost numbers I will see on a 99 ETC with O-ringed head 10thous. over gasket, Mach7's and a drag comp. I am about to order boost gauges and need to decide what range to get. I am planning to put a boost gauge on the cold pipe so i can see how much boost the B2 is putting out and then of course a gauge to see total boost. i figure a 0-100 for the total boost, but don't no about the boost out of the B2 0-35 or 0-60? Also would like to be able to see drive pressure so I can better tune waste gates and decide if I need to go to a HX40 exhaust housing. What do you guys use to monitor drive pressure? I guess I could just use a boost gauge but not sure how much steel line you would need to run to deal with the heat? Thank you in advance!! Lowell

 

[RonA]

With a 35/40 on top and an external wastegate you probably won't be seeing over 70psi so 0-80 or 0-100 gauge will be ok. If you are using a wastegated housing you will need to get a 0-100 for your drive pressure. Primary boost should max out at 40 or so. A 0-50 or 0-60 will work fine. About 2 feet of copper connected to the fitting in the maniflold seems to work fine. A couple of coils around the big end of a bat should stop the heat. 1/8" tubing plugs fairly quickly. Might try 3/16 or 1/4".

 

[Yooper1]

I have that same set up. . But I have mach 5's. . I have 100 psi for total boost, and 40 for the cold pipe on the bottom. I see around 63 psi. I have two blow off in the bottom pipe but a real nice set up. .

Got it all from power by poole.