ok, here are dyno graphs, one so you can see the hp/tq better, and one so you can see a/f better. Let me know if anything looks out of the ordinary, and I also felt these numbers were a little low for my combo (its a 306 w/ AFR 185's, 10.4:1 comp, f-303 cam, explorer intake, 1.7rr, LT, o/r x-pipe, magna flow c/b, tremec 3550, 3:73 gears) what do you think?
a little input on my dynoe graph please
- Thread starter machstang23
- Start date
jd-hart
Member
After about 3,100 rpm you seem to start running "rich". I know not all tuners are the same, but on a n/a engine I was thinking they wanted you around 13:1 or so.
I think you gave up some power there running so rich. I am thinking that A/F line should be a lot straighter than that......
I am sure the dyno gods will chime in soon though....
I think you gave up some power there running so rich. I am thinking that A/F line should be a lot straighter than that......
I am sure the dyno gods will chime in soon though....
well, it was just a dyno day at a meet, no tuning, but the tuner did say that it was running rich and that 13 to 1 would be better for it. He didn't really have a whole lot of time to discuss it with me because there was a line of cars waiting to go behind me that is why I seek advise here. the initial timing is at 14 with the spout out, don't know what total was because it was just 2 quick runs and then off the dyno, no tuning. I figured my intake would hold me back some, but I didn't think that much. So how can I lean it up some right now the fuel pressure is set at 43ish with the vacuum line off, and I have 30lb injectors with matching maf. would turning the FP down help?
man, this is great... I'm getting real time advise, thanks bentley... so short of a tune, there isn't really much I can do other then just turn the f/p down a little and see where I am at... Would a better intake (like an RPMII) that allowed more air help to lean it out some, or would the computer just compensate for the added air and dump even more fuel?
I am thinking 24# injectors would have worked better but that should easily be fixed with the tune. The explorer intake is basicly the same thing as a gt40 which should be fine for your setup, but yes a RPM II would be a nice intake to swap out for. Set the FP to 39 and then check your plugs, its pretty hard to determine where you are at without a wideband or tuner. Like I said before with as it sits I see no reason why it cant make 300 rwhp, a cooler day with really help things out also. Last time my car was on the dyno getting tuned it would lose 15-20 hp after two runs just because it was getting warm. 92 degrees and a turbo inside arent a good mix. Just trying to show you how much temps can affect things, clearly your car will react different to the temps thought. I am sure someone else will chime in and give you even more help, not completely up to date on NA cars.
Injectors aren't too big at all and are not the problem. Try backing the FP to 40 psi. The problem is when you rely on a 'calibrated' mass air to trick the eec to make the injectors work, doesn't always work. Try more timing and maybe backing the FP a tad will help straighten it out.
95Cobra302
Founding Member
My brother had his mach 1 dynoed at VMP. It's only about 15 min from our house. Hopefully I can get the cobra down there too. Justin is a cool guy. He could probably tune that thing up pretty good for you.
yeah, he tuned my mach 1 as well... I tried to schedule an appointment for him to do my car, but he didn't want to do such an old car, he told me that he would tune it if I converted it to an EEC-V computer and I don't really plan on doing that so...
My 2 cents
The intake dosn't match the AFR's very well. I'm guessing 20 hp. gain or more going w/ systemax or edlbrock 2, even trick flow track heat.
The cam could be improved for another 15 h.p aprox.
Run the best fuel you have hopfully atleast 92 octane, move your base to 18 deg.
Your injectors seem ok but I would change them to 24's for better driveablity and keep your presure up for a better spray 40 plus.
All those changes I bet you will make 330- 350 rwhp .
Your A/F ratio looks not to bad, not perfect ,I don't think you will gain a whole lot from a good tune at this point.
I'm not an expert but every time one of my cars didn't make big power on the dyno I never gave up and sure learned alot.
The intake dosn't match the AFR's very well. I'm guessing 20 hp. gain or more going w/ systemax or edlbrock 2, even trick flow track heat.
The cam could be improved for another 15 h.p aprox.
Run the best fuel you have hopfully atleast 92 octane, move your base to 18 deg.
Your injectors seem ok but I would change them to 24's for better driveablity and keep your presure up for a better spray 40 plus.
All those changes I bet you will make 330- 350 rwhp .
Your A/F ratio looks not to bad, not perfect ,I don't think you will gain a whole lot from a good tune at this point.
I'm not an expert but every time one of my cars didn't make big power on the dyno I never gave up and sure learned alot.
joel5.0
Member
306 CID + AFR 185 heads signing off before 6000 rpms? .......... yep, you got problems there. And the F-303 is one of them.
the cam and intake are holding it back. The stock Explorer flows ~205cfm peak and the heads flow 275 cfm peak. Porting the lower intake will get intake flow up to 230-250cfm but for best peak power you want a RPMII or Holley that both flow ~260cfm stock.
