TorqueFreaks with my new 1.7 rockers for my "stockish" 5.0

[Visceral]

Here's a poor pic of the dyno. Two afters and one before.

View attachment 523262

In David Vizard's book about 2 Billion 5.0 dyno tests or whatever, he notes that he *lost* 1hp form the 1.7 swap because of the stock springs. You now see some more information to back this up. I gained roughly 10 lbft accross the board with the rockers, and roughly 10rwhp peak. However with the stock springs you can see the valvetrain fall apart after 5600. The almost invisible "before" green line goes to 6000 without such trouble.

Other significant mods: Cobra intake (also in the before as well) and 4.10s (-8-12rwhp on dynojets generally, but on in both before and after)
Conclusion: 1.7 rockers are worth it (10rwhp/10rwtq) as a relatively easy swap, IF you swap the stock springs for something without 125k miles on them at the same time (about double the expense/work).

I put this up here because after searching all I found was supposition on these rocker's worth on a stockish 5.0

NOW, if it will cool off and dry up I will take the car to the strip and see if Im in the 12.7s or 12.8s and at what mph.

 

[Jon]

Very nice power for the mods you have!
You should run it at Woodburn tomorrow.

 

[Scooby5.0Doo]

im about the same in power minuse the 410s i got 327 just goes to show you have much gears will help

 

[Skoobie]

Dear god! You ran a 12.9 on those mods?!?!?! I think I need a new short block or something...perhaps some driving skills would help too Congrats man, would love to see her in action

 

[Visceral]

Dear god! You ran a 12.9 on those mods?!?!?! I think I need a new short block or something...perhaps some driving skills would help too Congrats man, would love to see her in action

Actually, 12.9 without any of the mods mentioned except the 4.10s. (stock intake, stock rockers) Its not so much driving IMHO, but non-engine mods that do it. Alot of folks go for the challenge to go 12s with a stock longblock, but generally only those with 5-speed coupes make it.

The prescription is something Bob Cosby put on the internet several years ago -> (I only can find it in text form... there are links somewhere )
------------------------------------------------------------------------

from:
My 'bolt-on' 12 Second ET Recipe, By Bob Cosby


Running a 12.9 with a nearly stock 5.0 is not as hard as it might sound. The main ingredients are: a fairly lightweight 5.0, a motor in good tune, the right mix of bolt-ons, slicks, and very aggresive driving.

Below is a list of mods, in no particular order, that I believe are capable of turning an average 5.0 into a 12 Second 1/4 miler. Keep in mind that this implies 12 Seconds on a drag strip, on slicks, not on the street on radials. Also, folks at a higher elevation will have a more difficult time breaking into the 12's:

- 26x8 Slicks

- 3.73 or 4.10 Gear

- Short accessory belt

- Off-road exhaust

- Headers (prefer long-tubes)

- Underdrive pulleys

- Remove the air silencer

- Ram-air/some sort of cold-air inflow, minimum K&N

- If a Mass-air car, a larger sensor

- 65mm TB with matching EGR plate

- Remove front swaybar

- Remove the clutch fan at the track

- Advance timing to approx 13 deg

- Good tune-up (new plugs, wires, rotor)

- Remove all loose items in car (spare tire, jack, etc)

-Courage. If you're scared of breaking it, you probably won't run the number!

The key to a 12 second ET with a near stock car is getting the car to launch hard and performing very fast shifts. Initially, launch the car around 5000 rpms. Do a hard power shift in all gears around 5200 on the stock tach. Cool the upper plenum with ice before a run, and push the car through the staging lanes as much as possible.

Some additional things that I would recommend include:

-Boxed upper/lower control arms with urethene bushings.

-Air bag in the passenger side rear spring.

-Move the battery to the trunk/hatch area

-Synthetic lubricants

-Pro 5.0 shifter

-Light-weight rims with skinnie front wheels/tires

-Remove any weight you feel you can do without

Some things I WOULD NOT BUY for a STOCK motor:

-"off-the-shelf" chips (ADS, Hypertech, etc)

-high-dollar spark plugs

-aftermarket ignition systems (2 steps are nice though)

-24# injectors

I can't stress how important it is to get the car to hook and launch hard. The 60 and 330 ft times are by far the most important. Work on the launch and shifting, the ET's will fall. I have personally seen several 5.0's run in the 12's with similar mods to what I have listed. In my opinion, there is nothing extraordinary about any of them, or my own.

If you like, e-mail me: [email protected]
-----------------------------------------------------------------------

 

[Visceral]

Very nice power for the mods you have!
You should run it at Woodburn tomorrow.

Seems "wet" out there. I dont think my 26x8s work quite so well in these conditions

 

[stock50LX]

Here's a poor pic of the dyno. Two afters and one before.

View attachment 523258

In David Vizard's book about 2 Billion 5.0 dyno tests or whatever, he notes that he *lost* 1hp form the 1.7 swap because of the stock springs. You now see some more information to back this up. I gained roughly 10 lbft accross the board with the rockers, and roughly 10rwhp peak. However with the stock springs you can see the valvetrain fall apart after 5600. The almost invisible "before" green line goes to 6000 without such trouble.

Other significant mods: Cobra intake (also in the before as well) and 4.10s (-8-12rwhp on dynojets generally, but on in both before and after)
Conclusion: 1.7 rockers are worth it (10rwhp/10rwtq) as a relatively easy swap, IF you swap the stock springs for something without 125k miles on them at the same time (about double the expense/work).

I put this up here because after searching all I found was supposition on these rocker's worth on a stockish 5.0

NOW, if it will cool off and dry up I will take the car to the strip and see if Im in the 12.7s or 12.8s and at what mph.

I like your approach -empirical evidence is the most convincing, especially in the automotive performance arena where there are so many claims. Did you replace 1.6 roller rockers or 1.6 factory-type rockers? I assume the answer is the latter. It would be interesting to see what roller rockers (same ratio) bring to the table over stock rockers.

 

[Scooby5.0Doo]

heres my dyno run. i still dont know how to get the pic in the message

 

[Stangler]

That's pretty good for a stock 5.0!! Nice numbers!!!

 

[Visceral]

I like your approach -empirical evidence is the most convincing, especially in the automotive performance arena where there are so many claims. Did you replace 1.6 roller rockers or 1.6 factory-type rockers? I assume the answer is the latter. It would be interesting to see what roller rockers (same ratio) bring to the table over stock rockers.

Being scientific and empirical is easy if you are poor and dont have alot of time to work on the car

The rockers were the stock 1.6 non-roller factory rockers prior to the 1.7s

 

[Visceral]

heres my dyno run. i still dont know how to get the pic in the message

With the rising A:F at the end, it makes me wonder if you arent having some small fueling issues. Could be an old tired fuel pump or an old fuel filter.

Otherwise looks good and try and do one thing at a time and keep the chassis and traction ready for each new item. Ive spent thousands of dollars on transmission, chassis, and suspension, but only about $600 so far on the engine It keeps me feeling fast for the power mods I have.

 

[Scooby5.0Doo]

with all the parts on the car i spent about 2500 +500 for car so, so far i think im doing good

 

[Bob Cosby]

http://members.cox.net/bobcosby/stang/12sec.html



FYI....I made 237 RWHP running 12.5x @ 106-107 mph at a raceweight of ~3150 lbs. This was before the days of tuning on the dyno. The dyno run above was made prior to a head/cam swap and dyno tune.

 

[Visceral]

http://members.cox.net/bobcosby/stang/12sec.html



FYI....I made 237 RWHP running 12.5x @ 106-107 mph at a raceweight of ~3150 lbs. This was before the days of tuning on the dyno. The dyno run above was made prior to a head/cam swap and dyno tune.

Thanks for the link Bob... I had found that it seemed missing for some reason.

You see I dont just debate politics on F-body boards

As far as your 236rwhp + 3150 lbs -> 12.5 @ 107.... if it was reasonable to expect that WE could do that too... you wouldnt be so famous round these parts, would you?

 

[WANNA_BE_GT]

Mods?

I was wondering what your complete list of mods was... Just curious so I have something to shoot for

 

[Bob Cosby]

You see I dont just debate politics on F-body boards

LOL. It's too bad you're a leftist, bleeding heart liberal. If it weren't for that, you'd probably be a pretty good guy.

As far as your 236rwhp + 3150 lbs -> 12.5 @ 107.... if it was reasonable to expect that WE could do that too... you wouldnt be so famous round these parts, would you?

LOL. Ya ok. I just step on the gas and pull a little black lever. The car does the rest.


WANNA_BE_GT....you looking for my mods or someone else's? My old 5.0 page is at http://members.cox.net/bobcosby/stang/ , and has lots of info. It hasn't been updated in 3 years though.

Bob

 

[Visceral]

LOL. It's too bad you're a leftist, bleeding heart liberal. If it weren't for that, you'd probably be a pretty good guy.

Ive often thought the same thing.

LOL. Ya ok. I just step on the gas and pull a little black lever. The car does the rest.

Yeah... exactly me----> <---physics and poor shifting.

At least I look good tires up launching a 1.65 60' with a stock longblock

View attachment 523216

Shame I cant power-shift to save my ass. I just wonder how much awesome shifting could get me 4mph

 

[Bob Cosby]

Believe it or not, a hard, smooth powershift will help both ET and MPH. I see an easy 2 mph difference between grannyshifting and powershifting.

PS....put an airbag in your passenger-side rear spring and air it up to ~22 psi.

 

[Visceral]

Believe it or not, a hard, smooth powershift will help both ET and MPH. I see an easy 2 mph difference between grannyshifting and powershifting.

PS....put an airbag in your passenger-side rear spring and air it up to ~22 psi.

It was at 14psi in the photo... I thought I was pretty flat

 

[Bob Cosby]

LOL. Perhaps it's just the pic angle? I used to run air bags in both sides. Passenger side ~22 psi, driver's side ~6-7 psi.

Air bags are often overlooked, but are a cheap and easy way to really help a car hook and launch straight. I pull high 1.5's on DRs in my 99 Cobra all day long with a very mild, street-type suspension....with air bags.