Classic Mustangs (Tech) Technical discussions about the Mustangs of yester-year.

sooo much tuning to do with my engine

Thread Tools
 
Search this Thread
 
Old Aug 23, 2009 | 06:42 AM
  #1  
kalli's Avatar
kalli
Thread Starter
6th Gear Member
 
Joined: Oct 2006
Posts: 6,417
From: Cork, Ireland
Default sooo much tuning to do with my engine

the engine is wellbehaved, but there's something I'm doing wrong.
The G-Tech tells me 9.5s 1/8 miles and every racing calculator under the sun certifies that with 150HP. edelbrock advertises the combo with 350fwhp and I'd be glad to get 250rwhp out of it. It is strong, but it defiently does not feel like a 250HP car.
I think the biggest problem is the ignition curve. i tried 12 initial with 34 max, then i tried retarding 2 degrees which seems to make it slightly worse.and i believe i hear something like a slight dinging going up a hill with light throttle. i think I'll disconnect the vacuum advance completely and then try a few different settings, springs

Any opinions on that g-tech output below ?i think the 150HP seems quite right :-(

Old Aug 23, 2009 | 07:49 AM
  #2  
kalli's Avatar
kalli
Thread Starter
6th Gear Member
 
Joined: Oct 2006
Posts: 6,417
From: Cork, Ireland
Default

then, according to http://www.theautochannel.com/vehicl...f65mcont.frame the K-code was putting down those numbers:
Axle Ratio 4.11:1
0-30 mph 3.0s
0-60 mph 7.5s
Standing 1/4 mi 15.7 @ 89 mph
Top speed 117 mph
Source: Sports Car Graphic 9/64

i only have 3.5:1, but trac loc, which should help plenty getrting off the line
So it seems I beat that, how far am I really off ???
how much more is there in my engine? plenty or am i really at 300HP already ???
Old Aug 23, 2009 | 08:25 AM
  #3  
wrenchturner75's Avatar
wrenchturner75
2nd Gear Member
 
Joined: Jan 2008
Posts: 313
From: pa
Default

try setting your initial timing to 14 and if you have pinging when pulling a hill dial some advance out by adjusting your vacumn advance, most are adjustable by inserting a allen wrench through the vacumn nipple. i had the eddy top end kit on a 306 with forged flattop pistons and i ran the 670 street avenger and had the heads ported and it only mustered 330fwhp, dont get me wrong that car was fast with 4:11s and a 5 speed but i was expecting more hp than 330, with aluminum heads you can run a lot more timing than with iron heads, i say run more initial timing and back off on the advance till it stops pinging, 14 initial and 36-38deg all in by 3000rpm sounds about right. i
Old Aug 23, 2009 | 08:38 AM
  #4  
wrenchturner75's Avatar
wrenchturner75
2nd Gear Member
 
Joined: Jan 2008
Posts: 313
From: pa
Default

by the way i later changed the eddy cam out for a roller cam, i wasent about to pull the motor to have it dynoed again but i will tell ya that cam and spring swap alone made a hell of a difference, felt like it added 50 more hp. i think the cam that comes with there kit is crap, just my opinion.
Old Aug 23, 2009 | 12:19 PM
  #5  
2+2GT's Avatar
2+2GT
6th Gear Member
 
Joined: May 2009
Posts: 5,232
From: PA
Default

Originally Posted by kalli
I think the biggest problem is the ignition curve. i tried 12 initial with 34 max, then i tried retarding 2 degrees which seems to make it slightly worse.and i believe i hear something like a slight dinging going up a hill with light throttle. i think I'll disconnect the vacuum advance completely and then try a few different settings, springs
You aren't really addressing the advance curve, just the initial (idle) timing and the max limit. The rate at which the advance operates is critical to performance, and is often ignored or misunderstood even by professionals. The best thing to do is pull the distributor and take it to an "old timer" who has a distributor machine and knows what to do.

A good starting point would be to use the stock BOSS 302 vacuum advance and centrifugal advance curves. You can ignore the vacuum retard curve.

Old Aug 23, 2009 | 08:34 PM
  #6  
67mustang302's Avatar
67mustang302
6th Gear Member
 
Joined: Apr 2007
Posts: 10,468
From: California
Default

I wouldn't trust a g-tech as far as I could throw it. Go to a real track and find out for sure, I'm sure you'll find the g-tech is probably way off.
Old Aug 24, 2009 | 03:05 AM
  #7  
kalli's Avatar
kalli
Thread Starter
6th Gear Member
 
Joined: Oct 2006
Posts: 6,417
From: Cork, Ireland
Default

wrenchturner: will try that. however the post from 2+2 is less agreesive with 36 all in at 4000.

2+2: I actually had it correct according to the BOSS302 chart with the Mallory distributor. But the box died, pertronix went in, so I have to start from scratch.
since crankshaft=2x camshaft, I just translated the numbers like:
2000rpm: 5 to 9.5 degrees centrifugal
4000rpm: 17 to 22 degrees centrifugal
etc
I'll re-try that, it's easy to do with a good timing gun and vacuum blocked.

67m302: the biggest problem is that there's no track in this country. i never heard of anyone dragracing. if i find out, I'll probably travel there to go down the strip. So the G-tech is all I have. I found the HP readings of it ridiculous, but somehow that thing is repeatable. So i can see improvements, even though I don't know how correct they are. it feels right though when i check on speed and gears in that chart. i once managed a 5.8s 0-60 and 1/8 mile of 9.5 seconds or so. and it felt quicker. stupid me never wrote down what I had as settings (ignition, jets .. etc)

I can't seem to find reliable info what the car actually should do in 1/8 mile. as said the K-code 271HP did standing 1/4 mi 15.7 @ 89 mph, which I should beat hands down. but racing calculators comment on this with 150HP ?!
So how much is actually really in there.
Old Aug 24, 2009 | 03:17 AM
  #8  
67mustang302's Avatar
67mustang302
6th Gear Member
 
Joined: Apr 2007
Posts: 10,468
From: California
Default

Hmm, it might almost be more accurate to mark off an 1/8 mile and run it and check your mph on the speedo.
Old Aug 24, 2009 | 04:19 AM
  #9  
kalli's Avatar
kalli
Thread Starter
6th Gear Member
 
Joined: Oct 2006
Posts: 6,417
From: Cork, Ireland
Default

Originally Posted by 67mustang302
Hmm, it might almost be more accurate to mark off an 1/8 mile and run it and check your mph on the speedo.
LOL. need a new speedo for that. the torque shoves the needle so it sticks. I only get a quick glimpse at speed when shifting. or cruising. There's very little police here, but I guess I'll be the unfortunate one caught with a yardstick out in the middle of the night :-]
Old Aug 24, 2009 | 04:27 AM
  #10  
kalli's Avatar
kalli
Thread Starter
6th Gear Member
 
Joined: Oct 2006
Posts: 6,417
From: Cork, Ireland
Default

actually, i used google maps and marked it off there. there's a straight stretch that's 1/8 mile plus|minus 10 yards.i'll try that

Last edited by kalli; Aug 24, 2009 at 05:20 AM.



All times are GMT -5. The time now is 11:25 AM.