I've revved it clear to 5800, thank you very much.

 

thats all the further that baby cam pulls that’s why.

 

the 3.75" blower pulley with the stock size crank pulley is making a solid 13 lbs and tickles 14lbs up top. It also makes some solid heat

 

lean on it a bit more and that heat is gonna get carried away. Kenne Bells go from hot to uncontrollable fairly quick.

 

Key word "Revved"....

 

Maxing out the rotor speed on that 3.6L with a 8.25" crank and 3.4" blower pulley bumps boost up to ~20psi per my calculations (which make rough assumptions on engine VE and blower efficiency based on existing results). That's 21% more airflow and 42% more pressure which as Pat mentioned, makes a proportionate amount more heat. The intake track would also need to checked to insure it would support the 2K CFM air volume. I am pretty sure KB provided flow bench results for the Mammoth intake but the throttle body and intake tube may still be a restriction. You should have the bigun intercooler but I am not convinced it is any better than the early ic's if the passages are not specifically separated. However, if the IC is good, you may be able to make improvements with a larger heat exchanger and higher flowing pump to offset the extra heat.
With that said, If you go the 20psi route, you are going to need E85, meth (or both) and significantly reduced timing with the existing 10:39:1. But, IMO, its not out of the realm of possibility.

 

are you sure that is the max? I have a 3.5, 3.25 and 3.0" pulley that came with the blower. I think the 3" pulley puts it at a 2.5 ratio with a 8" crank pulley. I have the frozen boost type 101 heat exchanger with a rule 2000 bilge pump in a 8-10 gallon reserve. the heads are the PRC aftermarket LS3 as cast with the 257cc intake runners, 2.170" / 1.600" Valves. At what point is the heat "uncomfortable?" I haven't really leaned on this thing yet. It has only seen 14* timing at WOT with 16gph 100% meth. The meth doesn't seem to have an effect on temps at all but I don't mind the added octane.

 

If you use the ATI 4% OD pulley (7.95") a 3" pulley is a 2.65 pulley ratio spinning the blower to 19875 rpm at 7500 engine rpm and theoretically making 23psi on your setup. ATI 7%OD (8.19") and a 3.25 blower is just about right at 18900@7500 making 21.45psi.

A lot of guys on here would say my IATs are 'uncomfortable' but I'm still able to run 20* on 93 pump gas (E5-10 around here) without detonation evident on KR or plugs. I do run it a little fat to compensate and start pulling timing at 160* IIRC. If I had to quantify it, I would say 250+ would start to get uncomfortable with one of our setups.

I keep coming back to the 7500 redline though. Do you have the valve train to support it? You also imply the boost rises on the top end. This tells me the engine is not as efficient up top where the boost starts climbing. Could be a valve train stability issue or just does not need to be spun that high.

 

I'd have to pull a log, but it literally tickles 14lbs up top. it runs solid 13.6ish through the rpm range. As far as the valvetrain is concerned, I have the upgraded PRC hollow valves, PRC/TSP low lift springs, Johnson lifters. I probably don't NEED to go to 7,500 rpm, but it has been there. I think last time i was in there i set a 7,100 shift point with 7,300 redline. there was no evidence of valvetrain issues right up until the timing chain let loose lol.

the location of the MAT sensor on these blowers is terrible. watching the spike in MAT then the immediate drop after going WOT to off throttle makes me skeptical of the accuracy of the readings. the ford crowd has great success with the Kenne Bell blowers. What are they doing different?

 

If MAT rises under load rpm/load and then drops as you tip into the throttle, but comes up again once you get into boost and start making heat, then that's reasonable data. Could you post a screen shot of what the trace is actually doing as you roll into the throttle? What you described sounds normal, but I'd have to see it.