Rear Gear with a th350
01-29-2011, 09:24 PM
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Rear Gear with a th350 I am currently on a stock 10 bolt with 3.23's in it, and I have another 10 bolt with a set of 3.90's. My ? is I have been told that our Fbodies, don't like a lot of gear. I have a 4100 TS converter and im spraying 150 shot. As long as I can run 1/8 mile Im totally fine with that. I understand that street is gonna suck flying up and down the hwy, but honestly its not so great now. Can someone explain to me why this would be a bad move for me.
01-30-2011, 07:18 PM
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i have a standard gear set th400, 325 radials, 4.11 gear. only spraying 100. best 60'- 1.35 best et 10.29@132. it goes through the 1/4 at about 7k rpms.
01-30-2011, 10:07 PM
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Whoever told you these cars dont like some gear, is full of ****. That would definitely be a big upgrade for you. I ran 4.10s with my TH350 and 4500 stall through a 1/4 mile.
01-30-2011, 11:22 PM
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ok then whats your take on it, would it hurt me to go to the 3.90 gear over the current 3.23? stock ls1 bolt ons with ms4 cam, 150 shot, and I spin the car 6800-7k. I really don't think that its gonna kill my rpm range. I go thru the 1/8th in 2nd gear
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01-31-2011, 06:33 AM
#10
Gearing choice, next to converter choice are two of the biggest ones you will ever make. When it comes to racing Fbodies, the "Race Weight" is certainly on the heavier side (unless you want to gut the car), and having that gearing (coupled with proper suspension and tire setup) will help the first 60 feet greatly and when it comes to your cam.
MS4 cars have no bottom end so basically you need to get moving as quickly as one possibly can.
You run 1/8th mile so beleive me its a good move. The person who mentioned this to you POSSIBLY is talking about the car as a overall package. NOT having a O/D sucks but thats racing.
MS4 cars have no bottom end so basically you need to get moving as quickly as one possibly can.
You run 1/8th mile so beleive me its a good move. The person who mentioned this to you POSSIBLY is talking about the car as a overall package. NOT having a O/D sucks but thats racing.
01-31-2011, 12:27 PM
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thank you guys for that bit of information. this kinda info is what I was looking for. If anyone else has anything to add I would certainly appreciate it. I know that hwy is gonna suck, which actually it does now so Im cool with that. I was just looking for some people who have actually done it, because to me it makes sense, especially i think it would help put me up in the higher rpm's and that's where my car seem to like to be. Car weighs 3200 lbs without me in it, im 300 so 3500 it is on race weight. Hope to get some more outta it this year, but main thing is to dial my susp in. New drag bar, adj tq arm, lca relo, coil overs with adj qa1's up front, and rears. alot to do just gotta wait for weather to break
01-31-2011, 03:32 PM
#13
I run 4.11's, 28" tire, th350, and run 127mph in the 1/4. I also have an MS4 and I can assure you that a lower gear ratio will help. If it was a track only 1/8 mile car I would tell you to slap some 4.56's in it and really wake it up.
Maybe the person you spoke to was referring to the 10 bolt not liking the lower gear? The smaller pinion gear reduces contact area and increases the chance of popping teeth off the ring gear. So there would be some truth in it if that were the case.
Maybe the person you spoke to was referring to the 10 bolt not liking the lower gear? The smaller pinion gear reduces contact area and increases the chance of popping teeth off the ring gear. So there would be some truth in it if that were the case.
01-31-2011, 03:58 PM
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About what RPM are you at crossing the line? I'm running 4.10s and a th350 and I think I'll be trapping at or near 140mph with the new setup and I'm wondering if a 28" tire will be enough.
Sorry to hijack the thread
Sorry to hijack the thread
01-31-2011, 06:38 PM
#15
With 3.90's cruising around on the street will be fine. Once you get on the highway you'll see 3000rpm-3200rpm doing around 60ish give or take a little. You won't want to make any voyages, but a short little trip here and there will be fine. This is assuming a 26" tall tire, again give or take a little. If the converter is loose the rpm will be higher. In the 1/8th mile your car will love it. I'm assuming you are trapping 97-100 based on your 7.0 ET. Swap it out and have some fun.
02-01-2011, 12:51 PM
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Im trapping 98mph right now. Car had low bottle pressure so im sure there is more in it. Think ima go ahead and throw it in and see what happens. I run a 28 " tire. Im not worried bout the hwy trips, I got nothing but time.
03-14-2011, 02:40 PM
#20
That 10 bolt won't hold up very long at all with the 3.90 gear. You definitely need more gear with the t350. It has a 2.40 first gear whereas a 4l60e has a 3.07 first gear. That is why A4 cars run good with 3.23 gears. If you get a rearend under it I would def go with 4.10 -4.30 for 1/8th mile. You 60 ft would improve alot. Get you a bottle heater too so you can get that pressure consistent 950 psi. If you want your tuneup to be right and stock bottom end stay together bottle pressure is just as important as timing, plugs, and fuel.