Dyno Run

[coolblue65]

Looks like I am going to finally get my stang on to a dyno this Saturday. I am hoping for numbers in the mid 300s at the wheels.

Anyone want to take guess what kind of power she will put down?

Here are the engine specs below:

DSS 347 Shortblock
(compression is supposed to be ~10.5:1 if I remember correctly)
AFR 185s Heads
Comp XE274HR Cam
Victor Jr
650 Mighty Demon
Fidanza Al. Flywheel
Hooker Comp LT's
Magnaflow 2.5 exhaust

Tremec 3550, Aluminum driveshaft, 3.55 gears

 

[dodgestang]

Lower

 

[classic boost]

yeah, 350ish is very optimistic.
275. good luck and keep us posted.

 

[coolblue65]

yeah, 350ish is very optimistic.
275. good luck and keep us posted.

I almost made that much with my old 289!

Yeah, I know 350rwhp might be a bit optimistic, but I would think it should at least break into the 300's, I have seen several very comparable builds with engine dyno numbers into the 400's.

oh well we'll see Saturday

 

[iskwezm]

i'll say the 330's

 

[Decurion]

317

I'd say more, but thats a fairly small carb.

 

[classic boost]

coolblue65,
is the engine combo them same as when you ran 109mph? that's partly what i'm basing my guess off of.

 

[coolblue65]

coolblue65,
is the engine combo them same as when you ran 109mph? that's partly what i'm basing my guess off of.

mostly- the mighty demon is new vs. my old Edelbrock, exhaust is new, 2.5", x-pipe, magnaflows vs old 2.25" with flowmasters

That trip to the drag strip was plagued with problems, mainly having traction issues off the line, and my clutch peddle kept sticking to the floor so I would physically have to hit with my foot to get it to pop back up..... so I expect better times with the spring removed and my new drag radials.

 

[blown65]

I'll say 325. Good Luck!

What kind of dyno though, that will make a diff.

 

[HookandLadder]

317. 332 after you dial it in.

 

[coolblue65]

RESULTS

oh the joys of hot rodding.....

While I am not thrilled, I am not completely disappointed, here are the results from the one and only pull (not even a full one) I was able to make today:

303 RWHP & 339 RWTQ, it was only spun 4750 RPM

Basically its way lean, ~14.2:1, so they cut the first run short and wouldn't do anymore. Although HP #'s were still climbing at a fairly quick rate, which makes me feel good so I know there is still plenty more power there. To clarify, this was not a tuning session and it was a group dyno day so there was no opportunity for tuning at that time.

I am glad it at least got into the 300's! I am going to make an appointment with them for a full tuning session.

Here is the video: YouTube - '65 Mustang 347 Stroker Dyno Pull 1


Oh, the dyno was a brand new DYNOJET

 

[blown65]

Ya, thats way way lean. Better throw some jets in it next time at the strip, heck Id probably go up 3 or 4 sizes all the way around and then start there with you being that lean.

Was anyone elses A/F readings wacky? Since they were new, how far in was the o2 sensor into the tailpipe?

Thats why I love the engine dyno, find that stuff out before throwing it in the car. All the pulls you want, easy access and about 300 bucks, really cant beat it.

 

[coolblue65]

Ya, thats way way lean. Better throw some jets in it next time at the strip, heck Id probably go up 3 or 4 sizes all the way around and then start there with you being that lean.

Was anyone elses A/F readings wacky? Since they were new, how far in was the o2 sensor into the tailpipe?

Thats why I love the engine dyno, find that stuff out before throwing it in the car. All the pulls you want, easy access and about 300 bucks, really cant beat it.

I am going to contact Barry Grant and see what kind of recommendation they would make as far as jets just to get me started. From their website it looks like the primary jets are #71 and the secondaries are #79.

The sensor was stuck pretty far in there, we saw a problem like that earlier in the day on a C5 vette, so it was one of the first things I looked at. No one else seemed to have any problems.

They quoted my a flat rate of $350 to put the car on the dyno and get it tuned right- which seems fairly reasonable.

 

[blown65]

Ya, thats not too bad, locally I did 3 pulls and tuning for about 200-250 but they were hungry for work so cut a deal. Its funny though, most with demons end up running rich out of the box not lean. BUT that was the basic demons.

Personally I'd just throw about 3 sizes up in jetting, and then go visit that dyno again and make a pull. See where that gets you on a/f. I really dont think you need to spend 350 bucks to get your fuel set. A few runs at the strip and you'll know what your car likes for timing pretty quickly.

More fun at the strip though, just jet up, make a pass, jet up again. If your mph increases it still wants more fuel.

 

[brianj5600]

Did you run it with the air filter on? Mine leans out one full number removing the air filter. From 12.1 with filter to 13.1 w/o. Also most people say an inertia dyno does not load a motor as much as real world and end up going faster at the strip by richening up the tune from a dyno. I use the mph at the strip to get best performance and don't worry about A/F ratio. I data log almost all my runs plus some tuning pulls on the street. The best info from A/F for me is cruise and the curve accross the rpm range at wot.

 

[coolblue65]

Did you run it with the air filter on? Mine leans out one full number removing the air filter. From 12.1 with filter to 13.1 w/o. Also most people say an inertia dyno does not load a motor as much as real world and end up going faster at the strip by richening up the tune from a dyno. I use the mph at the strip to get best performance and don't worry about A/F ratio. I data log almost all my runs plus some tuning pulls on the street. The best info from A/F for me is cruise and the curve accross the rpm range at wot.

yeah i ran it with the air filter on. I saw a kit jet kit for 40 bucks, that I think I will pick up.

 

[classic boost]

I saw a kit jet kit for 40 bucks, that I think I will pick up.

best money a carb guy can spend.

 

[coolblue65]

I have two questions for everyone then,

1. Is 3 jet sizes up a good start?

2. Any tips on changing the jets? (I used to have an edelbrock, this Demon is new to me)

 

[10secgoal]

Ahhh good ole lean Demon. I'd go 5-6 only based on the one I just did. It was almost 15-1 on a 378. Picked up 10 rwhp per jet. Ended up with like 9 more jets than we started with. Search on google for pics....demons are like holley's in that aspect.