This is topic Guess my dyno numbers... in forum Tech Talk at Northern California Ford Owners  .


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Posted by Jeff S (Member # 371) on :
 
I'm reposting so that I may acutally get some guess's since i'm heading to the dyno in a few hours. [Big Grin]

I'd like to hear what you guys think this combo will make on the dyno. Here are the specs:

306ci 8.5 to 1 compression
TFS heads with port work by a random shop
TFS Stage 1 cam
Edelbrock RPM intake (unported)
1 5/8" LT's with 2.5" offroad exhuast
Vortech S-trim @ 12psi
100 octane

The car is a 5-speed.
 
Posted by LAST302 (Member # 808) on :
 
489rwhp 453ftlbstorque
***Let us know later. I am very curious!!
 
Posted by AaronC (Member # 86) on :
 
I'll guess 525-550 but I have no idea. Good luck!
 
Posted by shade-tree (Member # 298) on :
 
just to be a pain [Wink] 325 rwhp (belt flying off at 3k [Big Grin] )
 
Posted by st5150 (Member # 51) on :
 
511 rwhp. Make sure you post your results ASAP [Smile]

Is Byron tuning it?
 
Posted by Jeff S (Member # 371) on :
 
Byron? [Roll Eyes] I'm tuning it myself with a PMS
 
Posted by st5150 (Member # 51) on :
 
quote:
Originally posted by Jeff S:
Byron? [Roll Eyes] I'm tuning it myself with a PMS
Oh yeah, I forgot... I Private Messaged you my "how to" on tuning power adder cars [Big Grin] [Wink] [dance]
 
Posted by 66 AC COBRA (Member # 904) on :
 
jeff, i will be running a similar combo, what size tb/egr spacer are u running, i hope for good numbers out of u, that will give me hope
 
Posted by bunchmyfunky (Member # 360) on :
 
Are you going to Apex if so what time? I might run over and check it out, I'm in SJ today
 
Posted by Jeff S (Member # 371) on :
 
st5150,

Yup, however the reason I asked for your theory is becasue you stated that it was different then the typical "internet theory". It looked pretty conventional to me, what are your main gripes?

66 AC COBRA,

It has a 70mm TB.
 
Posted by st5150 (Member # 51) on :
 
Jeff S- Got any links? I haven't read/found anything about tuning online, then again I was out of the scene all of last year.
 
Posted by Jeff S (Member # 371) on :
 
[Frown] Well I have the dyno result and they're not quite what I expected. For some reason the car is making peak power really early and then falling off fast! I'd expect this combo to peak around 5800-6000rpms. If anyone has any suggestions on what to look at please let me know. Here are the result with a super rich A/F and 23 degress total timing:

-
 
Posted by 93PONY (Member # 60) on :
 
What valvesprings are you using?
Peak torque at ~5000rpm....HP should peak ~6100-6300.
 
Posted by onesicklx (Member # 285) on :
 
quote:
Originally posted by Jeff S:
[Frown] Well I have the dyno result and they're not quite what I expected. For some reason the car is making peak power really early and then falling off fast! I'd expect this combo to peak around 5800-6000rpms. If anyone has any suggestions on what to look at please let me know. Here are the result with a super rich A/F and 23 degress total timing:

-
hey jeff is this panchos coupe...
 
Posted by Jeff S (Member # 371) on :
 
93PONY,

I'm almost positive that the springs have 135# seat pressure, since the heads were mine a few years back and I *think* I had Gromms install them.

Another thing the car has been doing the past few days is that when you start it up after sitting for a few minutes it will make a ticking sound in the valvetrain almost like a lifter is not pully pumped up. This doesn't always happen upon startup but does maybe 50/50 at random times and the sound seems to go away after 10 seconds or so.

onesicklx,

Yes.

[ February 06, 2003, 07:23 PM: Message edited by: Jeff S ]
 
Posted by LAST302 (Member # 808) on :
 
I think it may be your choice of cam. Before I put my blower on and during the process of building a new motor I was going to reuse my tfs stage 1 cam on this new low compression blower motor and alot of people told me including trick flow that that cam was not a good choice for a blower motor. Just a thought.
 
Posted by 93PONY (Member # 60) on :
 
I think the cam is a fine choice. I've witnessed a 5mph gain from the swap on a blower car....from a 212/224 114LSA comp cam to the TFS 1. By the power graphs, it also looks to be installed on a good ICL.

135lb seat is a little low for the amount of boost it's running. But max lift pressure is were you really need the spring. Too bad you don't know the spring part #....I'd be able to find/figure out the max open pressure.

Figure this:
A 2.02 valve has roughly a 3.2sq inch surface area. Multiply that by 12psi & the force on the intake valve is 38lbs. So, in effect under full boost the seat pressure of those 135lb springs is ~97lbs....& that's if the springs aren't fitiqued.

Stock lifters can take a little over 400lbs before they collapse. I'd spring a combo like that in the 350lb+ range at max lift.
Something like the Comp 978 or 914's would work okay.
 
Posted by SIR Paint Job w/ '84 Tercel Sr. (Member # 1708) on :
 
any belt slip?
 
Posted by Jeff S (Member # 371) on :
 
93PONY,

The boost pressure reducing spring pressure makes sence to me mathematically/logically, but at the same time confuses me. Are you saying that a cam which requires 125# seat pressure on a NA setup will then need to have 163# seat pressure if you add 12psi to that engine?
 
Posted by Jeff S (Member # 371) on :
 
I wouldn't be suprised if the belt was slipping because before we dynoed the car I was looking at the belt and noticed the rib's were royally jacked! My friend swore that the belt has never slipped on the street, so I shrugged and said "ok, but get a new belt asap". One one or two of the pulls someone did watch the gauge and it did make 12psi, FWIW.
 
Posted by 93PONY (Member # 60) on :
 
quote:
Originally posted by Jeff S:
93PONY,

The boost pressure reducing spring pressure makes sence to me mathematically/logically, but at the same time confuses me. Are you saying that a cam which requires 125# seat pressure on a NA setup will then need to have 163# seat pressure if you add 12psi to that engine?
Yes. That is essentially what I'm saying. Although seat pressure isn't as important as open pressure. Valvefloat occurs at max lift & boost will hang the valves open on the down-stroke of the lobe. So you can use springs with 130lbs seat, as long as they have 350+lbs open at max lift. The benifits of dual & triple spring setups.

I would also think the more likely culprit would be belt slip. Torque should have been much higher at 5000rpm.
 
Posted by st5150 (Member # 51) on :
 
Well it looks like shade-tree was the closest again [worship]

Jeff--Here is what I can tell from the graph:

- There is almost 10 rwhp to be gained from leaning her out.

- Those heads aren't ported. Maybe a "stage 0.5"

- Spark blow out maybe?

- Belt slip... probably. Watch the boost gauge throughout a 4 gear pull.... it should build up build up build up, and then "slip" down a few psi and say there. This is a typical sign of belt slip.

-23 degrees with 100 octane? Why? [Confused] There is a lot of RWHP on the table here. How did the car respond to more timing.

-The peaks sound about right. A blower doesn't push up the power band much. It does keep it from falling after the power peak though. I think with the belt, air fuel and timing issue adress, it will peak around 5400-5600 where its suppose to. NA this motor would peak at 5200-5400.

-You should race 93PONY with that car [Big Grin]
 
Posted by Jeff S (Member # 371) on :
 
st5150,

-Yes I realize the A/F could be leaned out and I also thought that more timing would help. I went from 23-25 and noticed no gain so I kept it at 23. I wasn't trying to perfect the A/F ratio since I knew there was a problem with something causing the early drop in power.

-The heads are ported/opened up enough to match to a 1262 gasket. Maybe it's just a shitty port job.

- Plugs are 3923's gapped at 32

-Belt slip is a definite possibility and if you saw the belt you'd be suprised that it was making any boost. He swears no slip though. I tried calling him earlier to go re-verify with a 4th gear pull but I was unable to reach him.

-Blowers do push the powerband up a decent amount, in my experience atleast 400rpm and I was expecting a peak of atleast 5800-6000rpm and then a slow drop off from there.

Another interesting fact about the car is that later tonight while driving around he noticed he was only getting 3-4" of vacumn which ended up being due to a vacumn cap being blown off of a intake fitting. I'm sure boost was being lost through that if it was like that on the dyno.
 
Posted by SIR Paint Job w/ '84 Tercel Sr. (Member # 1708) on :
 
what do you mean ONLY?
my car idles at 4" with no vacuum leaks. [Cool]
 
Posted by Jeff S (Member # 371) on :
 
Fixed vacumn leaks and put a new belt on.

Results: 14psi at 5800 and lots of tire smoke in 3rd! We'll be heading back to the dyno to make sure the A/F up top is in check and hopefully we'll get closer to that 500hp goal.

[Big Grin] [burnout]
 




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