Yup, ram tuning works on all engines. Unfortunately, our runners are so short that the effective 2nd and 3rd order pulses are way out of range in terms of rpm. Cross sectional diameter determines the rpm range when velocity reaches its peak, which mostly determines peak torque rpm. The runner length determines the rpm range where the reversion wave heads back toward the valve the next time it opens, creating a sort of passive supercharging. If you know the air pressure diff., temperature and the area of the cross section, you can find out the velocity and use it to determine the runner length that will provide resonant tuning in the rpm range you want. I developed an intake for cobras that beat the best in the business. 60rwhp gain at redline with only a 3lb ft loss down low...both of which were unheard of on these N/A 4 valve 4.6's. My car was the test bed, and it took many many tries before I got there. Took alot of reading fluid dynamics books for dummies as well. 20 years of porting didnt hurt. When things got bad at work, my intake business kept me alive. People all over the country were sending me their intakes. I ended up having to quit, and basically gave all my tricks away. Now there are people all over doing their own work, making serious gains, and taking all the credit. I was about to get a full on feature on my intakes in 5.0 magazine, and then I had to call it quits because I used to do all the work, at my work, and there was a new ownership, with new policies and a whole different mentality which threw fringe benefits out the window. I was living in a little condo at the time, so I had nowhere to do the volume of work I would see had the feature happened.
Anyway, the air pressure will alter the speed of the resonant "bouncing", which will alter the pulse order which is the most effective. A 12 inch runner would peak hp at 6000, and torque peaked at 5000, which was dead on with where the math said it should be. After adding a blower with 11psi, it was now peaking hp at 6800. My 10 inch runner intake (with a few plenum tricks), peaked at 6000 like before, but held that peak solid to 7000, where the curve had usually dropped like a rock. Those engines are very peaky, so this was a very much needed boost in the powerband. If there are some FI long runner intakes out there that would bolt up to these TR's, I think the midrange torque could be improved by over 100lb. ft. Easily. A 7 inch runner intake I had made, lost 100lbs at 4000. At peak, the power was up 8hp, but it was a good lesson in the effects runner length has. And this was 100lbs, on a 320hp N/A motor. Extremely significant. The engine was an absolute DOG. The TR engines, given their low rpm peaks, would probably benefit greatly from a 12-14 inch runner (not including the runner in the head), with no loss up high..assuming its not a highly modified, high rpm motor.
