Cobra1: I have tested an M1 at 740 HP in a 454. One of our customers put the same system on a 502 and made a bit more. That little blower was only running about 61% efficiency at that operating point, so discharge temps were high, but the big intercooler we used dropped intake air temp to 90F with 70F lake water. If you bought the M5 intercooler you have lots of cooling capacity but put some thought into how you duct the air blower to intercooler to throttle body. Try to avoid elbows.

Sean H: Tell us more about that intercooler setup pictured above. What are the two metal tubes with black hose and clamps?

RichardC: You and GPM should get together and talk cams. Then tell me!

This is how the intercooler shown on page two looks when mounted on the modified tunnel ram intake. The upper plenum with internal vanes and upside down throttle bodies is kind of an Rtech trademark also seen on our HP500EFI system. The intercooler core is 900 in3 and uses 40 GPM of water. Available in both aluminum and cupronickel. We're thinking of calling it the "who's your daddy" of all intercoolers.

the two pipes with the black 90's are from the intercooler to the carb box..

the intercooler is fed down the sides of the bilge from the turbos...

i don't know if those are still in there or not... it is a lot of intercooler either way...

intercooler still in carb box...

Holy Sh!t! Am I seeing things, or does that setup use both of those modified Dominators? Think of the airflow they must generate under boost! I wouldn't want the job of tuning that setup!

Wow, lots of good information in this thread. Not to hijack (well ok maybe a little hijack), but here's a question: If someone were to put together a BBC combo using an M3/504 charger and cooler, either 532 or 565 ci, ceramic coated 355 CNC Dart heads, Dart single plane intake, 2000 cfm throttle body, EM EFI w/75 lb/hr injectors, and a hydraulic roller valve train, what displacement and compression would one use to optimize the performance of the M3 on 91 pump gas? What kind of power and torque might one expect? The fuel system should be good for around 950 hp @6000 rpm, but I'm wondering about the airflow of the M3.

I might know someone who has some of these parts laying around and would be curious about what to expect...

Thanks,
-Brian

Brian,I made 944 hp/962 ft lbs tq at 5600/4400 on a 540 w/afr 315's on pump gas using a m-3 and aw504 w/63lb injectors blowing thru a stock 502 throttle body/using merc mefi 3 and plenum on a modified 502 mpi intake this spring. I used ceramic coated pistons and thermal coated chambers and runners. You don't need a big throttle body,the blower will take care of that. My cam is .600 lift hyd roller,motor idles at 700 rpm's/10 inches of vacuum,Smitty
If your interested,heres the links:http://www.offshoreonly.com/forums/s...d.php?t=104484
http://www.offshoreonly.com/forums/s...d.php?t=103922

Hi Smitty, thanks for the info, that's exactly the kind of data I'm looking for! I know the heads and throttle body I have are a little big, but I've been using them on the current setup (a naturally aspirated 598) and would like to reuse. I'm swapping cranks to lose some cubes and torque now that it'll be getting some boost. No sense shredding the XR too quickly... Sounds like the M3 is providing enough air. 950ish is about what I am hoping to make. What kind of boost numbers did you see with that power level?

Regards,
-Brian

8-10 psi on dyno,I was using a 3.85 dia upper pulley with 12 rib m-3sc bottom pulley. We tried a 3.70 dia pulley too but I think my tune was too conservative or something became a limiting factor as hp only went up about 12-15 and tq only went up 20 ft lbs(was at about 11-12 psi boost). I put colder plugs in and straight race gas for that pull and that might have been over kill and kept it from gaining much but not sure. We had to pull crocketts wide band 02 sensors because the leaded race gas ruins them so we weren't sure if it was lean or rich.We probably didn't need to raise octane from 92 to 110 for 1 extra psi of boost. I'd keep the 598 ci unless you have other issues,I hear that steve morris built dan vining's (the 109 mph baja guy) that big,Smitty