Thanks Indycars and Grumpy. Our little XT is coming along quite nicely isn't it. Thinking back to when I thought of either bolting it on as cast or porting the runners and somehow adapting the dual throttle body to it. We certainly have taken a much different route.
What it is becoming is in fact the very intake I dreamed up and had planned to build 18 years ago before I settled on hotrodding the TPI instead. The ported G2s and ZZX cam are gonna love this little guy.
Grumpy, my exhaust, which is still in process, is a dual 2.5". I went with this size for logistical reasons and because if done correctly, the dual 2.5 should not be restrictive at my power level.
The key as I understand it is to be sure the entire system flows as well as 2.5" pipe. Therefore, the mufflers are 3" id with cone reducers at each end to transition from the pipe without turbulence. I chose Classic Chambered Powersticks because they fit the space they need to fit and the 3" units have a full unobstructed 2.5" flow path.
I am also building a resonation chamber to install as close to 18" from the header collectors as possible. My headers are not long tube, but they are a very nice set of stainless 1 3/4" primary, 2.5" collector short tubes. Very light and have been durable over the 18 years theyve been installed with thick flanges that don't leak.
The resonation chamber will be as close to 355cu in as I can fit in the space allowed. My design will be a little short of that. I have to review my notes but i think it comes out to about 300cid.
Resonation chamber equal to engine cid and 18 inch secondary pipes would be ideal for a 5,000rpm torque peak, if I remember my math correctly. The resonation chamber will also double as a balance box for the dual pipes. If i can get a free moment, I will post a drawing of the internal design.
