Ok It's time to fix the rear...

I need to know what gears to install....

Moroso speed calculator puts me here:

28" Tall Tire w/ 4.56's =111MPH @6k RPM
28" Tall Tire w/ 4.56's =120MPH @6.5k RPM
28" Tall Tire w/ 4.11's =122MPH @6k RPM
28" Tall Tire w/ 4.11's =132MPH @6.5k RPM

Motor Tranny Combo"
400 .030
Comp Mag 280 (6k shut off)
Vic Jr
Double Humps
Holley 750dp
Gutted HEI
Full MSD 6A w/ SS Coil 8.5mm Wires
1 3/4" Hooker S/C
3" Pipe 3" Borla XR-1's

TH350
2200 Stall
B&M Shift Kit


What gears should I use????

Question #2
Nitrous???

What part will this play on my gear selection?
I will start w/ a mild 100shot but will bump to 200 or so...

Thanks again
BADASS

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1974 Camaro
Some stuff, Still too slow...

[This message has been edited by BADASS2001CHEVY (edited October 20, 2003).]

I'm not a ratio expert, I only install them. You would probably need to use a computer program like desk top dyno or others to determine the right ratio. Finding someone who has a similar combination would also be helpfull.

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'69 RS/SS396 Pro Street
427 4 speed 9"
Byars Performance
High Performance Drive Train Parts And Service
www.lubedealer.com/biggearhead (http://www.lubedealer.com/biggearhead)

Ok buddy thanks anyways

BADASS

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1974 Camaro
Some stuff, Still too slow...

I ran your set up through Drag 2000 and you really don't have a choice but to run the 4.11's. The 4.11's put you at about 6300 RPM at the end of the 1/4 mile with a 28" tire assuming your motor has the stones to pull it. The 4.11's are just about perfect for strip performance. The 5.56's have you at redline by the 600 ft. mark so they would be fine if you are running an 1/8th mile track and had a ton of traction. Did you mean 4.56?

Either way N20 just makes the matter worse with either gearset and IMHO you should be going the other direction if N20 plays a major role.

.......

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1974 Camaro
Some stuff, Still too slow...

Yes 4.56's I have no idea why I said 5.56's...I will be racing 1/8th no 1/4


Does that help better?


BADASS

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1974 Camaro
Some stuff, Still too slow...

Your converter will have less slippage than mine, but I am seeing 6600 through the traps with 4.10 gears and a 26" slick at 115 mph.
I would stick with 4.10s as well, and consider going with a stall in the 2800 to 3400 range. (10" diameter)
Let your final RPM determine the power level of your nitrous kit. It may be 100, 125, 150, 175, or 200. (your internal components also determine this choice, namely pistons)
Off the topic a little, but a 200 horse kit engaged at 2200 RPM will likely splatter your engine due to the extremely long "hit" of nitrous that would enter the cylinders at such a low RPM. Plan on adding a window switch if 200 is in the plans.

hehe then 4.56s would work if staying 1/8, but beware of traction problems with that much gear and that little of tire.

Umm ok back on subject of GEARS...

some are saying yes some say no...Why the YES and why the NO?

Nitrous will be fine, I have the parts to hold it, The stall will change to a 10" after I get the dyno to figure out the power band..

Now why YES and why NO on 4.56's

BADASS

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1974 Camaro
Some stuff, Still too slow...

The only negative with the 4.56's is the possible traction problems off the line. I assume you are running a 9 or 10 by 28" full slick with proper traction devices, etc.
My first response was assuming 1/4 mile runs.
If this was a full drag car you could probably step up to 4.88's or even in the low 5's.
Keep in mind you should add between 5 and 10 percent for converter slippage once you install the new converter.
Expect that camshaft, depending on your head flow numbers, to be signing off at around 5500. Nitrous will usually LOWER your shift point.
Wow, look at all my contradictions, hehehe. http://www.nastyz28.com/ubb/redface.gif
Bottom line, are you planning to run this engine forever or do you plan to step it up? Will the N2O be used on a regular basis, or just once in a while.
These are questions you have to answer prior to choosing a gear ration.
If you plan on staying with your current combination and only plan to use the N2O the odd time go with the 4.56's,
If the N2O addiction seems like a real picture, go with the 4.10s as a 400 isn't too fussy and will drive through whatever gears you give them.
I ran 3.42s behind my 408 small block with a 5000 converter on 26" slicks, running 113.5 mph at an 11.96, 1.69 60' time, all engine in the quarter.
If you have a funtional rear end now, you may want to try it with the high stall before deciding what gears to run.

Ok here goes:

Rear is busted now thats why the gear change..

I will spray..I guess a lot its a street car but..Big BUT im not real worried about all the cry baby stuff involved w/ street cars. Gas mpg ect...

I will have to add more stall later after the dyno so I can get her in the TQ band.

Motor will go 6k easy, so thats the shit point, 1/8th mile is just fine for me.

The slicks are M/T ET Streets 28x12.5x15
Im running SSM bars w/ a 1.7 60' w/ the 2200 stall and the 3.42's.
I get good traction, lol


Here is my main questions..

#1 Will I run outa RPM on bottle in the 1/8th??

#2 Will the 4.11-4.56 be a big difference? If not I can save face w/ 4.11 and get same results.

#3 Still need die hard negatives on 4.56's

Thanks for your time, BTW where is Marv when you need him???


BADASS

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1974 Camaro
Some stuff, Still too slow...

I'm guessing the 1.7 60 time is on the spray with that converter and gear.
I just can't see you hitting 111 MPH with your current engine combo in the eigth even with 200 of nos and a 3000 stall with that tall a tire and 4.56 gears.
That being said, I doubt there would be much difference between them and 4.10s on the bottle. Off the bottle I would guess maybe a tenth or two difference between the two ratios.
Going from 3.42s to 4.10s, along with l/w spool, Cal Trac bars, cam change, etc only netted me 3 tenths improvement and 1.5 MPH in the QUARTER, along with about 800 RPM increase in trap RPM.
What was your trap RPM on the bottle with the 3.42 gears? I'm guessing you could make it through in second gear, am I correct?
Until tomorrow.....cya

I havent sprayed yet buddy. Thats an all motor 1.7 60' my trap was a 7.9@86 w/ a 2200 stall and 3.42's on a 28x12.5x15 ET Street
I shift into 3rd and pass the traps but I CANT keep it in 2nd threw the traps it backfires (floats the valves--I think)

Thanks

BADASS

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1974 Camaro
Some stuff, Still too slow...

Nice run on the engine, those double bumps are really helping you in the torque department.
I still feel the difference between the 2 ratios is minimal.

I hope you didnt think the 1.7 60' was on juice, lol

Ya Im almost set on 4.11's

BADASS

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1974 Camaro
Some stuff, Still too slow...

Geez, ya' run the guys combo on two different programs and ya' end up gettin' punk'd.

Anyway, here are the answers to your most recent round of questions. Keep in mind, these are simulations. You can make relative comparisions but not absolutes. My simulation of your set up assumes an AFR 190 head, 10:1 compression, Victor JR and 750 cfm carb. 3700 lb race weight. It runs about .1 faster than the numbers you have posted with your present combination.

1)Yes, you will run out of RPM on the bottle with the 4.56's. Launching with a full on 200 shot results in big time tire spin and crossing the 1/8 mile mark at 6600 RPM in 7.16 seconds. Your 2500 stall is now stalling in excess of 3500 RPM. BTW, the 4.56's have you at 5500 on motor. 7.79ET

And No. With 4.11's your cross the line at 5800 RPM and have less tire spin on your way to a quicker 7.08 ET. Still stalling high but not enough to loss traction in second gear with the 4.11's. BTW, the 4.11's have you crossing at 5300 and a 7.66ET on motor.

2) Yes, there will be a difference. The 4.11's are more streetable and put less strain on your motor. However, increased traction may make drivetrain parts breakage a greater probablility. All appearances are that you would be quicker in both the eighth and the quarter with the 4.11's as they get you a 11.9ET over the 12.01 with the 4.56s. You will not just save face but you will be faster with the 4.11's while enjoying much more relaxed seat time and your engine should last longer. When on spray, you run less danger of over-reving due to either lost traction or extended time at or over your redline.

3) See answers number 1 and 2. I don't know what to tell you if you cannot conclude that the 4.11's are the best choice of the two.

With all of that said, I'll mess with you a bit and tell you that the 3.42 gear that you have is faster than either the 4.11 or the 4.56 on spray.

Im sorry buddy I ment no harm at all....I really appreciate all the time you and other have taken to answer my questions...I have eventually decided on 4.11's due to your's theirs and others advise I once again thank everybody that helped me on my quest, lol

Thanks ZEE for that usefull info that help a lot actually you pushed me over the top w. that last post its 4.11's!! Thanks

BADASS

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1974 Camaro
Some stuff, Still too slow...

Don't worry I'm just giving ya' a hard time. Glad to help.

ZEE!!!
What programs do you use? Man, I ran my combo on desktop dragstrip and what a load of crap!! Apparently my combo is a total turd, it's supposed to run 10's at over 120.
I was hoping to provide some insite with my different combo's, not an absolute. http://www.nastyz28.com/ubb/smile.gif
I had mentioned that my combo only improved 3 tenths going from 3.42s to 4.10s in one of my posts.
Good luck and happy spraying!!!

I used both desk top drag and performance trends drag race analyzer. Desk top drag IMHO gives you 95% of the data you need to make decisions like this.