turbo questions

volksnut · Post by **volksnut** » Thu Dec 21, 2000 7:14 pm

building a 1835 with a(pull through) Rayjay B25 turbo, which carb would be better, a 40 DCOE or a 45? What compression should I run, and cam choice, more lift less duration? Also I'm building it on a budget so I'll be fabin the exhaust, I've heard a TriMil exhaust will work, are they just a baja exhaust with the 1 and 3 pipes go under motor? Any other tips? Oh and where can I get the manifold from the carb to turbo..cheap

volkaholic · Post by **volkaholic** » Mon Dec 25, 2000 6:58 pm

Keep your CR between 7:1 & 8:1 for a street engine. You are correct, you want high lift & short duration, many choose a new "turbo" cam, some a "mild" street cam, other use the stock bug cam with 1.25:1 lifters. Exhaust manifold, I built mine from cutting up 2 old headers & rewelding them. Either 40 or 45 mm sidedrafts will work, the real trick is to be brave & reduce the venturi size, try a 32 or 34 mm. You don't need 38's on there. A good investment is an O2 sensor welded just before the turbo, so you can see the A/F ratio & it really helps with carb tuning.

good luck,
Volkaholic

volkaholic · Post by **volkaholic** » Mon Dec 25, 2000 7:10 pm

Also, I made my carb to turbo manifold from 2" water pipe, cut & welded. The hard part is cutting out a plate to fit from the carb to the manifold. Welding needs to be good, as leaks are bad (fire!). Also, bad welds look like bad welds & mess up the flow on the inside. I used 2" high temp hose to connect the turbo to the manifold. Silcone is better, but I could not find the ID I needed at the time. It is very important to not only support the carb with a brace to something solid (I ran a piece of all thread down to the #2 exhaust stud) but also connect the turbo to the manifold with a steel strap or similar. If you rely just on a hose connection, it WILL come loose from engine vibration. Please do this! I came real close to having my carb fall off during an otherwise fun drive.

later,
Volkaholic