| Re: Engine Dyno Predictions: |
Subject: Re: Engine Dyno Predictions: by TonyMamo on 2008/12/24 21:04:53 Guys, Here is all the pertinent data I acquired for this round of testing (which took quite a bit of time to gather I might add), that the guys who like to pour over the numbers will really enjoy. A big thanks goes out to Wes for providing the ported camel hump and the Dart heads and for taking all the time he did to baseline his car, hand deliver the heads to AFR for all the testing, taking the day off for the dyno day, etc. etc......I could go on and on. After speaking with him briefly after posting about the "challenge" some of you may remember on the "other board", it was clearly apparent to me this was a perfect situation with the right guy involved. Yes...AFR did discount the cylinder heads as promised months ago and yes, AFR did in fact foot the bill for the dyno testing but besides that the chips fell where they fell and driving to the dyno last Friday, although confident our product would once again deliver, I would be lying if I didnt say I was a little nervous knowing even just "OK" results would likley not be received well. Based on the numbers posted below I was hoping to see some solid gains (we had strong low/midlift gains on the intake side and a much stronger, more efficient exhaust port) and in the end I was certainly very pleased with the results. (Which were in line with my better expectations and needless to say I had a much more relaxing ride home!). BTW, you guys just looking at peak numbers are fooling yourselves. Our cars arent electric motors that operate at one RPM....as Beach touched on, you have to take the average power over the best 1500-2000 RPM span avaialable. You would obviously shift the AFR headed combo higher to take advantage of its huge gains in power past peak (the signs of an efficient higher flowing head btw). While there was a 25 HP differnce in the peak numbers (still sizable all things considered), there is closer to a 40 HP gain in average power and that would equate to serious improvement in SOTP acceleration and track times. Given the same quarterermile stretch of road, the AFR headed combo would be 3-4 car lengths ahead....thats a serious loss or a serious win depending on your vantage point. We arent taking about the difference being a fender or two or even a single car length. DONT easily dismiss that type of power differential (which the haters would incline you to do) and the fact you spent the same money makes it all that much sweeter. Enjoy the numbers....I invested many hours to coalate all of this information. ---------------------------------------------------------- INTAKE DATA (@28" of water with radiused entry on all heads LIFT...Fuelie-180 Dart-200 Dart-195 AFR (street) .200....146…….124……….143…………154 .300……195…….184……….195…………216 .400……239…….225……….238…………256 .500……252…….251……….268…………282 .550……257…….258……….272…………281 ------------------------------------------------------------------- .600……260…….261……….271…………280 .650……262…….261……….271…………280 .700……264…….262……….271…………280 EXHAUST DATA (@28" w/1.75 exhaust tube) .200……123……123……….116…………127 .300……158……151……….151…………173 .400……183……177……….180…………210 .500……199……198……….200…………230 .600……208……213……….211…………236 .700……214 Notes: I “fenced” off the .600 and up numbers on the intake because none of it applied to this testing…..but kept it in mainly for Wes’s benefit to compare his other fuelie head data (all the heads were flat there anywhere)which honestly was quite a bit optimistic. These are very good numbers for a ported camel hump head and having the time to llok them over carefully it was obvious to me Mike Stark spent alot of time on them. Even more modern ported Bowtie heads would be looking good here and the best I have seen those go with extensive time and money invested is in the 270-280 range but you would have likey invested twice the cost of an AFR head to accomplish that and it would have happened at a larger runner volume making them less efficient which would be mostly noticable in part throttle operation and some WOT power differences as well. More very important data The Dart 180 intake port poured 191 cc’s!! (quite a bit bigger than advertised). The fuelie head coincidentally poured the same 191 cc’s (lots of hogging there!) The Dart 200 head poured 201 cc’s (much closer to advertised) The AFR 195 street head poured 194 cc’s. Exhaust port volume Fuelie 67cc’s 180 and 200 cc Dart 75 cc’s 195 AFR 70 cc’s ------------------------------------------------------------ Thats about it for now....I will add more to this conversation at some point later time permitting. BTW, we seriously under-advertise our 195 cc exhaust flow data (intake side is pretty close). We were suppose to change that in our 09' catalog and overlooked it so we likely will leave the website alone and address both on 2010. I mention this only because the flow is alot more than we advertise and I didnt want anyone crying foul on the numbers. Wes can vouch for the fact these heads were not touched up one bit and were CNC ported only as delivered from us and others who have tested our heads can vouch for the fact the exhaust numbers on that particular line of heads (the 195's) are very conservative. The flow more on my equipment without a pipe than we advertise. Long story why but customers usually arent upset when their heads flow better than we claim. Wes....thanks again for the opportunity and all the hardwork. I told you a project of this magnitude would require lots of planning (and it did) but hopefully be very rewarding when the smoke cleared. I could tell you really enjoyed yourself the day we spent testing and swapping parts. Post that pic of the dyno day if you have it! Happy Holidays guys Tony |
