No, it will just move you to a higher rpm with less efficiency faster. That is great for moving off the line, but will read lower on the dyno then if allowed to get to the same RPM in low stall. The dyno is plotting RPM against power to the roller. It will see less power with less efficiency at the same rpm. Cheryl ---------- Post added at 01:02 PM ---------- Previous post was at 12:50 PM ---------- If you have the winpeg 7 files, have 6671 send them to me. I have the Dynojet software to graph it with hp, tq and A/F ratio here in most corrected forms or the uncorrected form. It is easier to understand all-together in a graph. Cheryl
I see that, even with the small spread of 5* between intake and exhaust duration it hold up well. wanted to keep the overlap low, so I kept the duration low on the exhaust for a better idle with the tight 109 LSA.
Joe cool project you have going:TU: It is always good to see the visual side of performance. You have good numbers for those that need to see in order to believe:Brow:. I would guess you won't need 4.10 gears with this combo. Good talking with you today. I'll have to stop by the next time I'm up your way.
Sorry doc. I should of said it this way " Doc did you see how good the 1x4 ran? " knowing that you are a big 1x4 fan. There was not a picture of it. Ok I will shut up now
Now,,, I am a simple man.... ya gotta show me a picture....:laugh: but,,, I still think:laugh: that if a pair of equally built engines were run side by side the single carb would out do the 2x4 set up in the qtr.... with a good intake under it.....:laugh: you have convinced me even further.....p But,,, and every body has a but,,,,, :idea2: you got to make sure that the air cleaner set up enhances the set up and not restrict the flow....back in the late 60's,,, holley did some experiments with air cleaners, and what everybody thought was the least restrictive, turned out not to be.... even with no aircleaner at all,, the engine ran stronger if a plate of sheet metal was fastened to the air horn flange.... by a significant amount.... and then there was cold vs warm vs hot air.... and so on.... I still have and use the old peterson books that I bought back then.....:Brow:
did a second dyno run. Andy will post the data. the bad news lost 17 peak tq at the engine. hp stayed the same. good news engine avg hp and tq went up. picked up a avg 10hp and 11tq. after 4500rpm it kept going up all the way to 5530rpm. at 5530 it has 32hp and 32tq more at the engine.
thanks Andy. if you can post the sheets sometime with rpm, hp and tq. on the sheets it shows tq staying higher after 4700 rpms.
No problem. If you click on the link below the graph, it says Joes Dyno.pdf, it has both data sets right next to each other. Otherwise I can get the actual sheets posted at some point this week.
no sorry Andy, i didn't know to click on there..the car feels faster mid and up top. wonder what happen with peak tq. changes were no synthectic oil, was running a little richer, timing set back 2*. bigger tires, cam retarded 2*. what helped top rpm hp was Bob did more head work and cam retarded 2* any one have any feed back about the lower tq and higher rpm horsepower ? peak tq came in 140 rpm higher and peak hp came in 80 rpms higher.
Old post wouldn't let me change attachments. Here's an updated graph Joe. I think the scale is why it looked funky. View attachment Joe Dyno Final.pdf
You do have some changes, tires, timing ect. Question is does it run better ? I am not sure you lost any peak numbers with the changes that you made.
I think I'd start by leaning it out a hair. If the AFR figures from the dyno sheet were correct, that would be a good move. Like Bob said, lots of things changed. It's hard to make meaningful comparisons that way. Obviously retarding the cam a few degrees certainly influenced the top end, while likely sacrificing a little low end. And at some point, with heads, you get to a point where they can support additional high RPM airflow, but increased port volume and decreased port velocity can hurt low end. Either way youve built one helluva stout piece! I know I gave up a lot of low end torque with my cam choice, but the mid-high RPM increase makes for a fun combo.
Andy, again thanks so much for posting the test. yes it was rich at 3600rpms it was at 12.5 ratio and after 4800 it went to 11.9 ratio, I will lean it out. dyno guy said taller tires take a little more power because it hurts the gear ratio. 2* should timing might help tq a little. not sure what Bob did with the heads, I think it had to help a lot with mid and top end. first dyno run at the engine, peak numbers came out 426hp and 549tq... this run was 425hp and 533tq. but like I said avg hp and tq were both up which should make faster track times.