4k shutoff

Topic: 4k shutoff (Read 5055 times) previous topic - next topic

Reply #15 – May 23, 2009, 04:35:39 PM

I'm`curious what tach you have as well. The E7 that mustangs have are the exact same as e6 minus the "high swirl" parts. If you factor in the cam, you have a turd. I have gotten my car over 4000 rpm in the past. It has no power. From about 1 to 2.5k rpm, the car feels decently fast, everything after that, I had to let up to let it shift.

I have had a couple of these cars faster then I will admit, but I went 13 miles in 7 minutes. About 7 minutes anyways. I used to live 13 miles away and moved when I turned 17. My dad would call me at 11pm and ask why I wasn't home, So I'd tell him I was on my way and get back less then 10 minutes later. I knew the road very well. It had a 60mph speed limit, and is dead as anything after about 5 pm. It uses for gravel trucks and thats pretty much it. I quit speeding after I got pulled over. I actually didn't know I got pulled over...

I got home and turned on the tv and started watching cops. Went and started a $1 pizza in the oven, and heard a knock on the door. There was a Utah highway patrol officer there. I asked him if there was something I could help him with and he said come outside. I did. He asked who drove the black car. I said I did. He asked me how fast I was going and I tried to play stupid and pretend I wasn't driving. He told me that he didn't clock me, but flipped around and did 110mph trying to catch up to me and couldn't. I told him my speedo only read to 85. He laughed and said the old 5.0 were alot better then the new 4.6's. He said if he ever saw me again I would get pulled over. Never saw him again.

4k shutoff

Reply #16 – May 23, 2009, 08:59:18 PM

Quote from: V8Demon;273879

Like Tom said, I'm doubting it's the springs as well -- at 4K RPM anyway...
Anyone know if there's a difference between the springs from HO to non HO? Part #'s or anything like that?

Also remember that a BONE STOCK AOD WILL NOT GIVE 4th/OD @ WOT....

Gotta back off it a bit.

I dunno about part numbers, but Mitchell ONDemand has different specs for HO VS non HO springs, so I'm guessing they're different parts. I've posted the spec table below.

I know my stock non-HO engine (only mods that would affect power are removed silencer and off-road style [no cats] true dual exhaust) falls on its face at about 3500 RPM, and that's with the T5 standard tranny. It pulls like a freight train to 3500, but trying to rev past that is futile, it's time to grab for another gear. It doesn't "hit the wall", so to speak, but it definitely stops making power. Given that the power peak of the non-HO engine was 3200 RPM, and my true duals and removed silencer might bump the peak up a few hundred RPM, that seems quite normal to me.

4k shutoff

Reply #17 – May 23, 2009, 10:52:45 PM

Quote from: TurboCoupe50;273877

Well I'm calling BULL shiznit on this... Six miles of stop/go & 45 mph averaged into 19 miles would probably mean you'd have to be running 150-160mph the for the 19mi... AS I SAID, BULL shiznit...

As far as prev turning 6500 another BS, the computer limits RPMs to 6250... Ain't happinin' with STOCK ford valve springs anyway...

Wanna try another story???

no "story" my friend. maybe something is messed up in my computer or my VSS, the speedomter is wrong.

i was turning 4k in OD which is .67:1, right? i have 2.73 rear gears, and 215/60-15 tires which measure out to 25.25" tall. if you do the math, it comes out to roughly 160mph. it took a long time to get to 4k, but it was there, in OD.

what reason do i have to lie? i'm not trying to impress anyone, it's likely that i will never meet anyone from this site. believe me or not, it's the truth.

anyways, thats beside the point. i need to figure out whats wrong with it causeing it to not rev over 4k

4k shutoff

Reply #18 – May 23, 2009, 11:09:46 PM

O/D is not engaged at more than approx 80% throttle... It ain't run 160mph even if you had a tail wind...

4k shutoff

Reply #19 – May 23, 2009, 11:11:25 PM

maybe trans was slipping and it was revving higher than it should have been at the speed it was going? i do know that i was passing cars like they were tied to stumps.

4k shutoff

Reply #20 – May 23, 2009, 11:11:43 PM

are 88 mustangs also limited to 110?

4k shutoff

Reply #21 – May 23, 2009, 11:15:01 PM

Quote from: Dougy_Fresh;273953

no "story" my friend. maybe something is messed up in my computer or my VSS, the speedomter is wrong.

i was turning 4k in OD which is .67:1, right? i have 2.73 rear gears, and 215/60-15 tires which measure out to 25.25" tall. if you do the math, it comes out to roughly 160mph. it took a long time to get to 4k, but it was there, in OD.

what reason do i have to lie? i'm not trying to impress anyone, it's likely that i will never meet anyone from this site. believe me or not, it's the truth.

anyways, thats beside the point. i need to figure out whats wrong with it causeing it to not rev over 4k

Your tire diameter is way off...a 225/60R15 measures out to a hair under 24.5" when mounted and on the car...do NOT use tire manufacturer specs for diameter, 9.9 out of 10 times, they're fubar.

I had a similar problem with my old HO equipped 'Bird...at approximately 4k rpm it would stop accelerating...in any gear...like it was the 6250rpm fuel shut off...full tune-up, still did it...new coil, still did it...MSD coil and wires, went away, but felt like it lacked a little power...I believe it was a high rpm lean miss...the reason I think that is because a few weeks later my stock fuel pump went, when I pulled it, the strainer was laying in the bottom of the tank....I think my pump was just on it's way out and the higher output of the coil was just a temporary band-aid of the actual problem.

But a SO 5.0 has no balls @4k rpm... I have swapped to a T-5, mustang shorty headers 2.5" OR-H, glass packs, HO upper and TB and bumped timing....1st gear...max is 4200 and that's pushing it...2nd gear is done by 4000 and all gears after that need to be yanked before 4000.

4k shutoff

Reply #22 – May 23, 2009, 11:30:43 PM

i'm going to check the fuel pressure again tomorrow. should it remain steady or should it drop/rise?

4k shutoff

Reply #23 – May 24, 2009, 08:41:54 AM

Idle/cruse is usually around 30-32psi... At WOT F/P should rise to 39psi and hold... If it never makes 39psi, either the pump is foobar or the regulator is faulty...

If pressure rises, then starts to fall as the RPMs climb, you have a weak pump or a restriction on the pressure line...

Mustangs did not have a speed limiter...

4k shutoff

Reply #24 – May 24, 2009, 11:03:09 AM

if i'm not mistaken, i believe it has 39 psi at idle....

i've had a few people tell me to check the pressure line for kinks. i will be putting it up on the lift today or tomorrow to check.

4k shutoff

Reply #25 – May 24, 2009, 08:38:52 PM

didnt get a chance to check fuel pressure today. anyone else care to give me ideas so that i can check more than one thing when i check stuff?

4k shutoff

Reply #26 – May 26, 2009, 01:12:07 AM

no kinked fuel line, but it did run out of gas in my girlfriends driveway. didnt get to make it to the shop.

bad thing about all this is that i am a mechanic and have pretty much any tool i could ever need at my brothers shop.

4k shutoff

Reply #27 – May 26, 2009, 12:20:45 PM

Quote from: TurboCoupe50;273956

O/D is not engaged at more than approx 80% throttle... It ain't run 160mph even if you had a tail wind...

Mine won't even do 160 :hick: I think a stock Turbo Coupe maxed out at around 145 or so. Being that these cars are 20+years old do you really want to do 160 mph on the stock suspension......

4k shutoff

Reply #28 – May 27, 2009, 12:59:21 PM

checked fuel pressure. roughly 32 at idle and 40 from just off idle all the way till it stutters. holds 40 and doesn't drop

4k shutoff

Reply #29 – May 27, 2009, 01:34:34 PM

Is this under a load or in park? Under a load @ WOT will use more gas than in park...