408ci and TH400 combo = 70mph @ 4000rpm. Can I safely drive at this high of an RPM?
03-17-2005, 12:13 PM
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408ci and TH400 combo = 70mph @ 4000rpm. Can I safely drive at this high of an RPM? With my 408 and th400 4K stall combo, I took it up to 70MPH and it was at 4000rpm, I quickly got off the highway and took side roads home.
But will I damage anything (springs, etc) by reving it this high for an extended period of time/miles?
But will I damage anything (springs, etc) by reving it this high for an extended period of time/miles?
03-17-2005, 12:24 PM
#5
you absolutly put more wear on the valve springs, so if you have a HUGE cam, id replace them once a season, $200 is cheap insurance. that is, id replace them every season if you do a lot of 4000rpm driving for long disanctes often. if its just once or so a month it sees highway duty, then every other season should be fine. i have a 400 in mine and i replaced the springs after one season but i also had a g5x3 which is hard on the springs period.
edit, i just noticed, we have the identical trans setup, same stall and everything. if you havent had it to the track yet, youre in for a big suprize. haha i love this trans!
edit, i just noticed, we have the identical trans setup, same stall and everything. if you havent had it to the track yet, youre in for a big suprize. haha i love this trans!
Last edited by Camaro_Zach; 03-17-2005 at 12:32 PM.
03-17-2005, 12:45 PM
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cam specs are 238 244 .605 .612 112 + 4
Yes, I was sure it's in 3rd; 1st and 2nd gear is useless. I am in them for about 2 seconds before I need to get into 3rd gear
My speedo has to be off
Yes, I was sure it's in 3rd; 1st and 2nd gear is useless. I am in them for about 2 seconds before I need to get into 3rd gear
My speedo has to be off
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03-17-2005, 01:04 PM
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Was there any traffic? if so were you flying by them? keeping up with them? getting passed by semi's?
My 67 with 400 (pontiac) and th400 cruises at ~3k with 3.55 rear gears, with the stock 14 inch rallye 2's.
I would get back on freeway and try to pace with someone where you can see their speedo or have someone pace in front of you.
My 67 with 400 (pontiac) and th400 cruises at ~3k with 3.55 rear gears, with the stock 14 inch rallye 2's.
I would get back on freeway and try to pace with someone where you can see their speedo or have someone pace in front of you.
03-17-2005, 01:12 PM
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3.73s with a 26" tire with a "good" converter will be 3500-3700 rpm at 70 so your speedo is a little off. 4.10s will be 3800-4000 at 70, at least thats what it has been with the cars I have had. You should be fine, the engine will let ya know if it doenst like it- the water or oil temp guage will let ya know that.
03-17-2005, 01:19 PM
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it seems to be a bit off. try to get your speedo checked with a tap software or pacing someone you know. i wouldnt drive for to long on the hw like that....it just to much premature wear on your motor, no matter wat kind of materials used..
03-17-2005, 03:19 PM
#14
no th400 ls1 car is a daily driver. at least i hope to god no one would do that.
gas is fine as long as you arent on the highway.
i got a 4k stall, trans brake, manual valvebody, 4.11 spool, i wouldnt have it any other way on a drag car. i love it.
oh and fyi, gas is the least of my expenses when owning a race car haha. seriously.
gas is fine as long as you arent on the highway.
i got a 4k stall, trans brake, manual valvebody, 4.11 spool, i wouldnt have it any other way on a drag car. i love it.
oh and fyi, gas is the least of my expenses when owning a race car haha. seriously.
03-17-2005, 05:40 PM
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70 mph was roughly 3800rpms in my TH-400 with 275/40/17's and 3.73's, right at my stall speed, so it doesn't seem that far off.
Mike, while nice, they make a heavy trans even heavier, and are a bit over $2,000 if I remember correctly. I'd look into a 4l80 before I dropped that kinda coin plus the cost of the original built trans.
Mike, while nice, they make a heavy trans even heavier, and are a bit over $2,000 if I remember correctly. I'd look into a 4l80 before I dropped that kinda coin plus the cost of the original built trans.
03-17-2005, 10:41 PM
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i just spoke to a guy on the 4l60.com site, anyways, he told he can build me a 4l80e with all the needed hardware, capable of 1000hp, for 5K...i think if your gonna spend tons of cash for a 1000hp motor might as well go for a bullet proof tranny....
03-17-2005, 10:50 PM
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Originally Posted by obZidian
i just spoke to a guy on the 4l60.com site, anyways, he told he can build me a 4l80e with all the needed hardware, capable of 1000hp, for 5K...i think if your gonna spend tons of cash for a 1000hp motor might as well go for a bullet proof tranny....
