View Full Version : Question On Rear Gear
09-30-2003, 10:33:00 PM
My current rear gear is a 4:10 & i use a 28x12.5x15 M/T Et Street tire.
Now through the traps on the juice its trapping ~6750rpm. I'm not crazy about these revs. She doesnt seem to be pulling much more at that speed, kind of flattens out around that rpm.
The cam is the Comp #12-900-9 and has an operating range of 3200-6200 Comp says.
Now should I retard the cam (this winter, im done my projects for this season!) or should i go down to a 3.73 gear?
09-30-2003, 11:14:00 PM
If you plan on running the nitrous all the time I would do the gears.
09-30-2003, 11:43:00 PM
What about a little more tire? It would take the least amount of effort.
09-30-2003, 11:55:00 PM
<font face="Arial,Verdana" size="2">Originally posted by Cam73:
What about a little more tire? It would take the least amount of effort.</font>
I was thinking that as well but I don't think he could go much taller unless he went to a narrower tire which may hurt traction.
10-01-2003, 02:39:00 AM
You could always run less nossss. http://www.nastyz28.com/ubb/wink.gif LOL
If you have enough converter the change to 3.73s shouldn't hurt too much off the gas and will work nicely with the gas.
Rustbucket : doing a bunch of "stuff" to his camaro to make it quicker next year
10-01-2003, 04:16:00 AM
I say keep the gear and retard the cam plus a bit taller tire.
Most of the time a taller tire (even if its a tad more skinny) will hook up better as the tire itself will have more give/wrinkle on a hard launch.
10-01-2003, 04:25:00 PM
Well the converter is a 9.5" stalling ~4000 or so.
I'd like to keep the 4:10's but i am not too crazy about the revs.
I am going to put the 210 jets in this weekend, how much more RPM will i pick up from an extra 60HP of squeeze?
10-01-2003, 09:07:00 PM
OK Carm your running dead on a 10% slip through the convertor at 6100, with your latest boosted time slips. That's pretty average (if not a little tight) for a 9" with this much stall. Let's assume you gain 5mph on the top end (which I really don't see from only 60HP add) but at 129 you would be at 6980rpm given the current losses in the convertor.
Have you looked at the other lines of tires. For example the 14x31 Hoosiers are 32.2" tall. I'm sure there are other 12.5" tires out there that will give just a 1/2" or thereabouts help on height.
10-01-2003, 09:51:00 PM
I would like to reissue my vote for 3.73 gears and this is why.
1) The change will drop your rpms enough to put you back in the "relaxed" zone.
2) The gears will help your car hook better.
3) My change from 3.42's to 4.10's, along with many other changes, only picked my car up about 3 tenths. My car was an 11 second car even with the 3.42's, and your's certainly will still be with the 3.73's
10-01-2003, 11:13:00 PM
Gears is what i'm leaning to......
But if i can fit a 29" tall tire without any body mods, then i will do it.
Anyone using anything taller than a 28" tire without having any body mods?
10-01-2003, 11:16:00 PM
I wish Carm would have put his latest updated signature in this thread.
11.7's @ 116 on the motor, 10.8's at 124 hosed with the 150 pills.
If he's truely addicted to the N2o I gotta agree. He's got too much gear. But n/a,, I think he's in the sweet spot. with a 10% loss in the convertor he should be at 6200 n/a in the traps. Less gear is going to hurt those times IMO. I also think there is more in the motor anyways.
10-02-2003, 06:19:00 AM
LOL i thought my sig would be a little too cocky for you guys in here http://www.nastyz28.com/ubb/biggrin.gif
Through the traps N/A its ~6200-6300.
I think i am addicted to the N2O, it's great. I love the way the motor sounds!
This weekend if it's all good i am definetly going to try & get those motor ET's down. She's still quite rich....traction & a cage for next yr are #1 (1.71 60'ft N/A, 1.61 on the giggle juice)
10-02-2003, 11:05:00 AM
Stroked,I have 28.5X 9's that fit well and I also have a set of 29X10's that came off a 2nd so they fit also.
I love the juice as well,it's quite addicting but for consistancy and cost I plan on running on motor most of the time so I plan on keeping the 4.11's which is why I bought the other slicks to see if I can get my rpm to stay under 7,000 on the buttom.
I'm not worried about the motor staying together but my cam and heads quit after 6500 or so anyway.
10-02-2003, 06:24:00 PM
Well if those 29X10's fit without me having to do any body mods (rolling the lip on the rear quarters) then i will get those for next season.
I try & run on the motor but i've tasted this juice & mmmmm is it ever good!
'81 Viper Blue Z-28
Comp Solid Roller
750 Mighty Demon
4:10 Rear End
TH-400, 9.5" 4200 stall
N.O.S. Cheater 150-250
11.74 @ 116 motor
10.86 @ 124.5 150 shot
10-02-2003, 09:51:00 PM
I'll let you know by the weekend how they fit on mine.I do know you have to beat in the inside of the wheel well where the seatbelt retractor is but nothing serious.
I'm liking the juice so much the Vega's getting it too.
10-06-2003, 05:23:00 PM
So Craggar, how did it fit?
10-07-2003, 01:16:00 AM
I didn't do anything this weekend but took them off the Vega tonight so I will try them tomorrow and let you know.
10-07-2003, 12:50:00 PM
I put the tire on which by the way are 29X11 and it is about a 1/2" from the spring but did not hit my wheel well lip even when I pushed down on it.
A 29X10 would probably work perfect for fit with the same b/s.
Sorry I couldn't get any pictures as my cheap digitial packed it in a while ago.
10-07-2003, 03:39:00 PM
Hey no prob Craggar.
I've got a friend here with a 3.90 gear for this winter....and tires i cant find any 29x10's?
Who makes yours?
10-07-2003, 04:30:00 PM
The ones I have are Hoosier's.
10-08-2003, 09:05:00 AM
I notice Tuk Tuk has 30X9's so you may want to ask him how they fit and what brand as well.
10-08-2003, 06:01:00 PM
Thx, I'll send him an email!