Engine dyno over sixty miles away. Chassis dyno about 5 miles down the road. Which would you choice and why?
The only real dyno IS the drag strip as quoted earlier. Either dyno is only a guess as to what is going to happen. The chassis dyno is much easier to fool with bogus numbers while the engine dyno ( what is called an eddy current R&D engine dyno) is as close to what the truth really is. In my NASCAR days, the biggest numbers were not the fastest engines we used on the track. A chassis dyno is good for looking to free up power in the drive line and looking at engine acceleration rates. This is something very few people look at. Also, look at the cars (complete engine and drive line) deceleration rates. This is all due to friction robbing places and parts.
For tuning, the chassis dyno is a very good tool for the time frame your running, but a good data recording system on board will do the very same thing, only all the time and any time you want to. It really is an on-board dyno. Plus, if instrumented on and for other cars, can be switched between all cars. You would be surprised how out of tune even new cars will get when big weather changes come along. Nothing bad or much, but more than enough for max power. Plus with on board data acquisition, trying new parts and components will show a plus or minus right away. Like did that carbon drive shaft really do anything? (Yes it did, more than we thought it would)
So, to answer this question. The answer is neither and both. I like to start off with a engine dyno then switch to data acquisition on board. Data acquisition is a pricey part to start with, but once installed, paid for it'll last almost forever. Well, that is until you figure out what's happening and decide MORE DATA!!! With todays racing even Saturday night local stuff to get that extra little bit of performance out of that Mopar I have to say with a heavy heart, ya just gotta have that data!
I have been working with a local guy here in Phoenix for several years on a 1965 Dodge REAL door slammer. 492 wedge engine, single 4 Holly Dominator 3850 pounds (original A/M radio worked real good until real bad tire shake) with NO power adders, low 9s @ 148 and plus MPH. Averages 1.3 60 foot times, good days 1.2s! When asked how did you hide the NOS, I simply say in a very snarky voice, all motor because that's for Chevys! The real trick is getting everything to work well together and NOT doing what everyone says works because everyone says. Number one trick, get it to breath well AND big numbers again isn't the trick. There is such a thing as volatility. Number 2 trick, almost everyone over cams or picks a cam company that is really a GM cam grinder. I personally like Crane. Third trick, pay alot of attention to the intake manifold (innards) and the exhaust headers. Size does really matter here more than most think. And, it's a big block, not a very high winding small block, OK. Look hard at torque (first) and HP then decide on RPM limit. Sometimes short shifting you can go faster. Try it. Another thing I just remembered, fuel pressure AND flow! We have 38psi to the regulator then 6.5psi to the -10 lines (2) that go to the carb. Think about this and tell me why?
Heads used, Mopar Stage 6 ported by Dick Landy years ago. Intake manifold, Mopar M1 that I took almost 2 garbage cans of aluminum chips out with my mill. Looks like a stock M1, but inside it's real different and flows perfectly FOR THAT engine. Cam is a custom roller by Crane, Chase Knight designed. He's probably forgotten more about Mopar cam profiles than most have ever learned. And really small compared to most other cam grinders designs.
Jeff (really old guys)
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