Well, I have learned a lot during my 5.0 build-up. The two main things that stick out in my accumulation of knowledge are-Mustangs are slow. Period. Nothing you can do short of a stroker or forced induction will make them fast.
The second thing I have learned is that all these mythical combinations are just that, and I must say I never SAW a fast NA302 with my own eyes. But I blindly went on building one. Anyways, it ran about what my old-school technician said it would, mid 14's in the mid 90's. He was not suprised as he had informed me I was being fed crap by all those who said a head/cam 5.0 with only GT40p's would do different. Anyways. I digress to his superior knowledge. The only thing I have left to do is play with the carburetor, which I intend to pull the holley 670CFM Vac secondary carb and put on a smaller doubble pumper style carb. Other than that, im out. Yes, I suppose I would sell the car, its perfect inside and out and has all new everything except sheet metal and interior and both are near perfect. Only problem it has is that its a 302 (albeit with a new motor and block) and thusly slow. My timeslip on my best pass read

2.15 60'
14.4X 1/4
97.?? (high 97 trap, cant recall exactly)

And here is what I wasted money on to get there.

FMS aluminum DS
UPR tubular upper/lower control arms
Probe forged pistons
GT40P heads
10.5:1 compression
4.10 gears
TKO500 transmission
FRPP Strut tower brace
50/50 lakewood shocks
4-way KYB AGX struts
245/60/15 cooper cobra gt's
670 CFM Holley Avenger
Holley Red Pump
1989 140mph speedomoeter
MSD ignition
MSD Pro Billet Dizzy
MAC shorty headers
BBK X-pipe
Flowmaster force II cat-back
Steeda full length subframes
3-core radiator
Stainless flex-a-lite fan
Underdriven crank pully
X303 cam
1.6 aluminum RR's
Edelbrock RPM Intake
Mallory return regulator
Upper/lower tq box reinforcements
New quad shocks
2.75" cowl hood
High volume oil pump
King Cobra clutch
Adjustable billet clutch quadrant
Billet flywheel
Audiovox CD player
TKO short throw handle
Moroso Valve covers

This ends my domestic related vehicle endevours and if I can find a buyer who will allow me to re-coupe some of what I spent, I plan on purchasing something that gets more than 20mpg. Probably a 5th gen prelude or something until I graduate and can afford something that doesnt need a laundry list of mods to hit mid 14's. Maybe something ///M powered or perhapse a Z06 or the like. Anyways, just thought I would reassure you LS1 guys that yes, a 302 ci motor is impossible to make fast no matter HOW MUCH money you throw at it unless you just REALLY break the bank doing it. Also, if someone wants to buy my failed creation, albeit althought its a new car, but slow, PM me with a REASONABLE offer and we might work something out. If not, it will do fine until I graduate college.

 

You have something wrong.... my BONE stock '89 5.0L GT ran a 14.1. With a few bolt-ons and a Cobra intake, it went 13.6 @ 101. Both times on regular street tires.

With TW heads, an E-303 cam, 3.55 gears, and full bolt-ons with LT headers it went 12.7 @ 108 on Nitto DRs w/stock suspension on a 1.9 60ft. I pulled M6 LS1s from a roll regularly.

 

You can say it all you want but I didnt see it. I guess that was my problem when I built this car, I listened to too many people. Anyways, my compression is great, all cylinders fire, I dont have any misses, and it pulls clean all the way up to 6K rpm. It will spin like mad on launch upon demand, and so on and so forth. The car appears to be running to its max potential, 302's just dont have the guts apparently, but if someone things I have something "wrong" I would love to hear what it is. Maybe I can fix this pile of $14K parts plus labor. Anyways, if not I am either selling it or just leaving it alone as its very streetable and reliable. So, shoot me an offer or some suggestions. I give up.

 

Oh, and this was on a stock short block with all bolt-on parts. Didn't mill the heads or anything. Also with no tuning other than timing via the distributor, and an adjustable fuel pressure regulator (notice the backfire on the 12.87 vid).

Here's a vid of the 13.6 pass (stock internals).

Here are vids from after the heads/cam swap:
Idling w/ no tailpipes
Playing around w/ no tailpipes

Burnout w/ full exhaust
A 12.87 pass w/ full exhaust

 

^sounds ike you must have gotten a freak or something. As for mine, its running as hard as it can I suppose. I am going to rip off the 670CFM carb and spend another $400 on a Barry Grand 575 speed demon mechanical carb. I that doesn't do it, then nothing will. Everything has been tripple-checked already. Its just a 302.

 

So was mine... just a 302. It sounds like your car has all of the right parts, and a good gear for the X-303. There's nothing wrong with the GT40p heads, even out of the box. They don't flow as well as AFR or TW heads, but they aren't that bad.

Have you had your car on a dyno yet? I'd be interested to hear the HP peak. You mentioned shifting at 6k RPM, but with your cam I'm thinking you should shift even higher as I shifted my E-303 at 6,200rpm. Also, you should be making close to or above 300rwhp. Unless your car is a heavy pig, it should be running mid-low 12s with any kind of traction.

 

I agree with LS1 Sounds, something is not right with your car. My bone stock 94 Cobra ran 14.4 @ 96 with 120k miles on it. That was on street tires with a 2.00 60'. Your 2.15 60' is killing you. Borrow some tires and test out that built drive line.

There's still hope for the 302s though. With a TTI single 63mm turbo my car went 12.04@119, 1.74 60' on pump gas. At that time it had 135k on the clock. Car was completely stock except for driveline and injectors.

 

What altatude Stanger?

 

His trap speed below 100 is not right though. Sparetire could be onto something with the altitude, but even then he should be trapping ~10 mph higher.

 

Wow! man I am sorry to hear that your car is only running 14's, after all that work. My 1991 notchback ran a 13.98 bone stock powershifting it. with 4.10's intake and slicks, front swaybar removal, more aggressive timing and unplugging the fuel pressure regulator it went 13.35. with 125 shot ZEX went 12.2's. 302 motors can be made to have power it is all in the Combo. I just finished building one and it should be right around 320-330 RWHP

Look at your 60 foot time you are obviously not getting any traction, buy a pair of Bfg Drag radials or borrow some slicks. your car should be in the high 12's to low 13's. 60 ft times should be around 1.8-1.9 or better also raise your shift points.

I do wonder why you went carb?
Any Dyno #s?
the weight of your car?
How much track experience ?

Give feedback, and try again, I would like to see this car in the 12's!

 

we are pretty close to sea level i was with him at the track in northwestern Lousiana

 

I just dont get that trap. Even if its runnign strong and clean, its not making the power it should. I wonder about how the cam is degreed and about the timing. Im also curious what kind of AF its running. A really rich car run just dandy and feel great, but be way down on power.

And even though nobody wants me to post it:
Is the throttle linkage all A OK? TPS sensor?
How good/acurate is the tach?


Dyno time might be the answer.

 

something sounds wrong. When I was in high school my friend had a 91 5.0 with just flowmaster exhaust, 3.73 gears, shifter, underdrive pulley, and maybe 1 or 2 other minor boltons and that car felt like it pulled hard. I think he ran like a 14.0 or something like that, remember he couldnt drive for **** then either, so that car could have probably ran mid 13's easily. It felt like it pulled really hard to me.

 

Why don't you spray it?

 

must have a problem, I know an 88 gt with bolt ons, gt40 intake, 4.30 gears and the ever important good driver mod and he was hitting 12.9s at the track

 

I would take your car to Houston where there are plenty of Mustang performance shops (unless you know of one close by) and have it checked out. There is no way those times are correct for those parts.

 

you have a serious problem that combo should run mid to high 12's easily. and i'm not a ford man but i have enough friends with 5.0's that would agree you have a decent combo with a problem somewhere. as far as a 302 being gutless a guy i know has one the runs 10's N/A

 

My 96 Mustang GT ran a 14.4 with only a catted magnaflow X-pipe, and a K&N filter.


Something is wrong with your car.

 

Ah, im sticking w/my mechanic. Its just a little motor and the heads arent that great. I am getting one of the better race-car builders to look at it this week and check my carb. All in all, not bad for the parts I have. Just not that great. I have accepted its fate as a pathetic venture and a horridly mis-matched combo.

No, I will not spray it. I have spent over $14K in parts etc. etc. and putting a bottle on a slow *** 302 just to hit mid 13's isnt my idea of respectable. I would rather just use it as a daily driver. So what if a civic beats it? its old technology I guess. Anywho, The secondaries sound like they are opening up. The motor sounds solid, I got 150 psi cranking compression across the board (stock 5.0s get 140ish or so, and I have higher compression but a larger cam and more valve overlap so 150 makes sense). Car idles great, accelerates cleanly, in good working order.

I shifted my best run at 6K on the stock tach (500rpm optomistic) and my second best run (down .5 mph and .2 seconds to a 14.6) at 6300 on the stock tach. IT cuts off at 6500 on the stock tach (6K MSD chip and inaccurate tach).

As stated, we were at sea level.

I dunno guys, every SERIOUS race car builder (people who run 8's all motor) has told me the car was gonna be a dog and I just kept listening to what I kept hearing from people telling me it would be "high 12's" and the company who sold me the motor claimed 290whp and "high 12's" But they are since out of business. I guess fraudulent claims pushed them under. Anywho, I will have the tuner guy look at my car sometime this week (tuesday maybe) and see what he uncovers. I doubt he will find anything meaningfully out of whack, Holley tune's their carbs pretty well from the factory (surely not 80whp off) and my MSD ignition fires great. Compression is good. No tapping or anything. The car is just slow. It needs a 408 or something big to make her go. Thats about all I can think of.

Kinda sad noone has shot me any numbers lol. I am looking to get into a Prelude or something that I can justify for college. A mid 14 second car that makes 20mpg and wakes the neighbors just isnt what I wanted. I was under the illusion of mid 13's to high 12's. Oh well, 3-4 years away from a Vette or something that doesnt need 14K to hit 14's. I will let you know what the tuner says, hopefully he discovers a reason, but I am a terribly unlucky person, always have been, and I think its just a bad combo and a lot of wasted money/magazene racing.

 

Its always "a guy someone knows" never "me" or anyone I see do it, lol. My friends cousins grandsons step brother in-law will race him in his time machine


Just a little tired of having everyone's favorite combo and doing just as my old-school tech said--stock. Kinda gets old always having to tell the guy he is right and that I was mis-led.