what hp/tq should my 306 have?

Hey guys,

Just built my 306 and have been running it for about a month, the motor feels great, but i wanted to know about how much horsepower it would make based from your guys experience. I would also like to know what ETs could be realistic as well. I plan on putting it on a chassis dyno, but my budget is near none, due to my expenses. Here is the combo,

- 306 --
- flat top pistons 10.2:1 comp
- 66 289 heads, 54cc 1.84/1.5, gasket matched exaust, removed lips in the bowls
- Tri-y headers, cant remember tube diameters
- Comp cams 270H cam 224/224 duration 500/500 lift hydrolic flat tappet
- Performer intake manifold (want rpm air gap for this combo)
- holley 600cfm vacume secondary (want 650 double pumper)
- Accel Dual points [img]/phpBB/images/smiles/icon_frown.gif[/img] (want...need MSD)
- 2.5in dual exaust flowmaster 40series

The car-----

- 66 Mustang coupe
- Aprox 3100lbs (read it as stock weight from factory)
- 3speed manual tranny, YES its a stick car, not auto (plan is a race built T5 tranny)
- 8in rear w/mini spool and 3.00:1 ratio (plan is a 9in w/4.11s)
- Tires 195/70/14, 24in tall, for ET purpse, assume it gets traction [img]/phpBB/images/smiles/icon_smile.gif[/img]
- Slapper traction bars

Should be it, I would be happy with mid 13's on this combo, I wonder what a T5 and a 9in rear would do as well. I want to take the car to irwindale very soon to get some ETs, its only a 1/8th mile, but i would like to get into the 8.6-9 range with tunning and great driving, with the last motor i ran 2.25 60foot times on a open peg leg rear end and a 2.79:1 ratio. Not bad for the poor traction i would get anytime i would hit the gas.


Thanks guys any in-put would be great

---Anthony
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Well I will take a swat at it.

I will estimate you have 240 HP at the tires, that puts you just barly in the 13`s around 100 mph. I dont think you can get in the mid 13`s without a few changes. Most of them you already have mentioned.

The only way you will know is take it to the track, it is much cheaper than the dyno, and MPH is a very good indicator of HP. With MPH you can estimate many things, granted they are estimates but can get you close none the less.
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With the 3:00 gears and performer intake, I'd guess more like low 14's.
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- - - - Track Times - - - -

Hey guys, raced the car at irwindale dragstrip this last thursday and have some impressive results.

1st run (best one of the night)----

RT -.730's very poor
60'- 2.1
ET - 8.87
Mph- 83

2nd run (pushed the car and got no traction, seemed to be water or some liquid on the line too though) - - -

RT - 700's
60'- 2.5 or so
330- still spinning em [img]/phpBB/images/smiles/icon_frown.gif[/img]
ET - 10.1 [img]/phpBB/images/smiles/icon_evil.gif[/img]
mph- 80 or so, dont understand that though, with all the spinning and all

3rd run (barly got in line to prove my cars worth, close to closing time) - - -

RT - 580's
60'- 2.3
ET - 9.06
mph- 82's


[addsig]

That's good! I didn't think it would be that quick. Congrats! [img]/phpBB/images/smiles/icon_biggrin.gif[/img]
[addsig]

Ok,

Man, the car ran better than i have imagined, i was hoping for times like this but started to think that i would be lucky for low 9's. I seriously think that on driving alone i can get the car down a couple of tenths. Further tunning, maybee another tenth. And thats not adding any other parts.

I wouldnt be surprised to see 8.5 on my next slips. If i could get a 2.25 with an open rear end. That 2.1 60' can probably go down to 1.9, on a good day maybee 1.8 with traction bars which i dont have installed.

Doing the math, 8.87 is a 13.67 in the quarter mile.

With a t5, rpm airgap, 650 carb, slicks, and some gears, i cant even wait to see what the car will do. Im going to say mid 7's are realistic.

Obviously you guys can see i am very happy and optamistic, basically because a lot of people were telling me my expectations were too high, and usually they are, but i think when racing the stang with the 289 helped me make realistic expectations on this motor, since i was hopping for 8's and thats what i got.

I'll keep you guys posted on my progress, i guess this is for all the guys in highschool or those of us that have a limited budget. Im only 19 and on a super tight budget, seriously i thought it would take a lot more money to just hit 8's on the 1/8th. Heh heh, i just cant wait to go faster.

---Anthony
[addsig]

That is awesome man, i know what its like building a stang on a tight budget. im 19 also and am building a 357w for my mustang. but its great fun. its my 3rd motor and im excited to see what it will do in the 1/4. good luck with hittin them 7s.

Your mph is your HP indicator. 83 mph is pretty good for a stocker! I was looking at some of my old timeslips from an old stock headed 306 bracket car that I once ran and my average 1/8 mi. time was 8.60 @ 79 mph. I could get a 1.90 60 ft time pretty consistently by using about 100 lbs of ballast and 8" street tires on a 9" posi. You should be able to get your 1/8 mi. times in the mid 8s with a little better traction. [img]/phpBB/images/smiles/icon_smile.gif[/img]

btw, 1.90-1.95 60ft times are about the limit without switching to some kind of sticky tire, positive traction, and decent gears.

_________________
1966 Mustang, Custom glass hood, 331 stroker, 5.4 H-beams, Probe pistons, ported TrickFlow heads, ported Stealth 8020, XER solid roller, Holley 750 HP, Hedmans, 4spd, 9"/3.50, BFG DR

"Too much for the street, not enough for Pro Stock"

<font size=-1>[ This Message was edited by: bluestreek on 1/27/03 11:12pm ]</font>

Yeah,

I hope to get it a little deeper into the 8's on my driving. Hope i get a chance to go out and race this thursday.

Anthony
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<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2003-01-26 20:15, 66Racer wrote:
Ok,

Doing the math, 8.87 is a 13.67 in the quarter mile.

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Looking at some old timeslips, an 8.87 is more than likely closer to 13.90s in the 1/4, and that's with a 4 speed. And for the life of me, I don't see how you managed 83 mph with your mild setup! It may take a little more than good driving to get it into the mid 13s. Ask anyone that's been there in a street car. That low geared 3 spd will help you out in the 1/8th but you'll wish you had another gear if you ever get a chance to go the full distance. When you hit 3rd with a 2.79 rear behind a 3 spd it's gonna be like dropping an anchor.


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