NMRA Factory Stock Build

[Bobco]

Well it's on. I am going to run my new GT in the NMRA factory stock class. Kooks is making a set of 1 5/8" headers. I will get a 2.75 exhaust built for it. Getting the one piece driveshaft and convertor for it next week. I am going to wait and do all the bottom stuff at once while it is up on the rack. Remove the back seat and make a cover to upholster the space left. 6 pt Chrome moly cage. Bolt in so I can take it out in between races. Plastic race buckets. Front skinnies probably Race Star wheels. 10" wide Race Stars in the back with drag radials.

Now for a diet. Any ideas? It has to weigh 3450 minimum with my 200lb butt in it.

Thanks,
Bobco

 

[wbt]

Check out my sig...

I would recommend CHE for all your chassis/suspension needs. The front sway bar delete is the lightest/best made unit I have seen for the S197.

Small battery, remove all engine covers, wheels/tires make a huge diff., seats like you mentioned, sound deadener under the factory carpet, hood liner, smaller front brakes, rear seat betls, spare tire/jack, exhaust, etc...

Adding weight will include roll bar, rear girdle, and axle-tube brace kit.

 

[Bobco]

wbt,

The rules state that you must run front and rear sway bars.

Chrome Moly weighs 1.36 lbs per foot. I guessed I will need roughly 23 ft. That adds about 30 lbs.

Do you think a rear end back brace is really necessary? The problem being is the pan hard bar is stupid close to the diff. cover. When I put the gear in my car I bought a Strange aluminum cover with the cap supports. I wont fit cause of the panhard bar. I could make a bar with an offset in the middlebut will NMRA not like it?

Never heard of CHE. What's their website?

The only other thing I thought of was the A/C compressor and condenser. That will be a last resort.

What do you think about gear. I need to go through the traps at low to mid 120's. Maybe I should get it dynoed and see where the power band is and gear accordingly. Using all 6 speeds. 4.88?? 5.12??? More??

Bobco

 

[wbt]

wbt,

The rules state that you must run front and rear sway bars.

Chrome Moly weighs 1.36 lbs per foot. I guessed I will need roughly 23 ft. That adds about 30 lbs.

Do you think a rear end back brace is really necessary? The problem being is the pan hard bar is stupid close to the diff. cover. When I put the gear in my car I bought a Strange aluminum cover with the cap supports. I wont fit cause of the panhard bar. I could make a bar with an offset in the middlebut will NMRA not like it?

Never heard of CHE. What's their website?

The only other thing I thought of was the A/C compressor and condenser. That will be a last resort.

What do you think about gear. I need to go through the traps at low to mid 120's. Maybe I should get it dynoed and see where the power band is and gear accordingly. Using all 6 speeds. 4.88?? 5.12??? More??

Bobco

Arg....forgot about the sway bar...poopy.

Expectation for weight on the roll bar will be around 60lbs. with chrome moly. Here is the one I will be using: Wolfe Race Craft - Detail

Good friend of mine who is a member here, kdanner, runs one and it was roughly 60lbs.

CHE's site is: Carriage House Engineering CHE Performance Products

Yes on the axle tube brace and girdle. Total weight is minimal and will help keep the rear end from grenading. Here is a pic of my setup:

Gear is dependent on converter and tire choice.

With the 275/60/15 limitation, you are looking at the following:

28" diameter
87.9" circumference

Looking at the auto 5th and 6th transmission ratios:

5th - .87
6th - .69

Remember the first gear in the auto is truck like at 4.17.

Personally I would like to be able to reach the 61st foot mark before shifting but it isn't mandatory...

Plugging in the numbers for rear gear:

120-125 MPH in 5th gear @ 7,153-7,453 RPM = 5.71 rear ratio

With the horribly low 1st gear, you will hit about 25MPH then shift into second. The good thing is, second on the auto is like being launched out of a cannon.

Just some thoughts and certainly should not be considered as the only option. Hope that helps.

 

[Bobco]

wbt,

Thanks for your input. You have been most helpful.

I haven't seen a brace like in your picture. The one I was thinking of had heims that went over the studs that push up against the bearing caps.

Wow! The 5.71 seem a bit radical and it is only using 5 gears. Will the transmission shift that fast?

I saw the pics of your car on the corral site. Any idea on the weight difference between the Race Stars and the Pro Stars?

Bobco

 

[wbt]

wbt,

Thanks for your input. You have been most helpful.

I haven't seen a brace like in your picture. The one I was thinking of had heims that went over the studs that push up against the bearing caps.

Wow! The 5.71 seem a bit radical and it is only using 5 gears. Will the transmission shift that fast?

I saw the pics of your car on the corral site. Any idea on the weight difference between the Race Stars and the Pro Stars?

Bobco

Anytime! :beer:

The 6R80 auto is the best ever seen in a Mustang from the factory. I may be going out on a limb here but with the right tune, I think you will have no issues with it and handling the quick shifts.

Good friend of mine's auto:

[youtube_browser]STmlGMANS0Q[/youtube_browser]

What stall are you looking at running?

Regarding the wheels, I couldn't tell you the weight difference. I haven't found them posted.

 

[Bobco]

Not sure on the stall yet. I have been talking with Rick LaBlanc at Livernois Performance. He is recommending a 3200 stall. I am wondering with the relatively small exhaust if a little tighter convertor won't work better. What do you think?

This all has to happen soon to be ready for the first race in Bradenton the first week of March.

I am going to ask him about the gear and rear suspension stuff. He went 10.90's with their 2011 auto. It had 12 to 1 pistons and ported heads. And big exhaust. He didn't think the pistons made much difference with the stock heads.

Bobco

 

[SID297]

Very cool. I look forward to seeing you run at the races this year.

 

[kevinp]

Biggest gear doesnt always get you to the end quicker.

Dont forget if you arent locking up the conveter at WOT you are going to to pull about 4-5% more rpm through the traps due to converter slippage. I would also check with a trans builder if the trans will do WOT shifts from 4th-5th-6th. Usually the OD parts are pretty weak.

Also I notice the 6R80 isnt on the transmission list, mmight be an oversight but I'd check with them.

They are really whacking these hard on weight, they tend to do that so the newer engines dont come in and start setting records. 3450 raceweight is going to be tough on one of these and keep everything for daily driving plus a roll bar.

FWIW a 5pt bar is NHRA legal to 9.99 so save an extra 10lbs and do a 5pt, my guess is you are going to need every 10lbs you can get.

Good luck and have fun with it..

 

[Bobco]

Looks like the BF Goodrich drag radials are the way to go. The Nitto's last longer and have better street manners especially in the rain. But the BFG's hook better at the track. The question now is Comp T/A or G-Force T/A. Any input? They have different tread design. I will run 275/60/15's. The most sidewall out of the three sizes you can run. On a 10" Race Star wheel.

Bobco

 

[Bobco]

BFG doesn't make a Comp T/A Drag Radial anymore. I bought a set of BFG G-force T/A.s mounted them on 10" Race Stars. Talked to Rick today on other isssues. He said he will get back to me tomarrow. Ordered a set of headers from Kooks. I will have Earl at Watson Engineerig make a 2.75" catless X-piped exhaust for it.

Hopefully get the convertor, driveshaft loop and one piece driveshaft installed in the next week or so. Wish I had more time. lol

Bobco

 

[assasinator]

tubular steeda radiator/swaybar mount. remove the z-brace.


for the power level you are talking, i bet the stock diff cover is ok. i would stall it just below full loaded converter rpm where the shifts drop it. ie, if it shifts and drops to 5500 in each gear id flash the converter to 4500-4700 rpms. leave the line at max torque.

because you are dealing with the best of all worlds, id gear it for everything. the pcm will handle the shift point, and im sure massaging the oil holes in the valve body can make it shift instantaneous. id tune it to lock up hard after it gets to shifting a few times.