MadMarv
May 8th, 04, 4:28 PM
I posted this in the trans forum like a week ago and really didn't get any help.
So sorry about the cross-forum stuff.
I have a turbo 400 with a gear vendors. I used the "Jake" method of 6d nails and some grinding and in 4 tries I got a good enough (actually, dead on if you ask me) for me shift governor based rpm of 6275 1-2 and 2-3, (2-3 I am pretty sure on) if I got a good enough glimpse at my tach when the 2-3 shifted. I checked the 2-3 shift @ 10am this morning after driving up and down this industrial park known for street racing three times checking for cops, then some utility workers were like "just do it!" So I warmed the tires up for them and then went down the road which is entirely too bump and ill taken care of for people to race on, (I suspect this is why they don't repave it) but I let off after the 2-3 shift because I was just checking RPMs and didn't want to go all the way to the stripe painted on the road for the street racers. Anyway... It was close-- Shift light came on (set for 6200), car shifted, light off, so I figured it was dead on.
But here is the problem, and I don't know if this is related to the governor or not. When I floor the car, it downshifts and immediatley hits the rev limiter (6500) and won't shift. This engine hits the rev limiter so easy its unreal, I don't think I ever hit the rev limiter in my hyd. roller engine, with this thing i hit it all the time and I don't know if its because something is screwed up in the trans or gear vendors or if the tires light up.. I have turned around to look for strips but never see any, but I don't know if you would be able to see strips like that. I don't think 6500 is going to hurt this rat, but I hestitate to put a higher rev limiter chip in there to see if that is whats holding it back from shifting again-- besides, even though it looked like the dyno runs could have kept going, he stopped my runs at 6200 because hp at tq had started to decline from 564hp (engine dyno) and 519/511 @ 5700/5800 to 473 ft-lbs and 559hp @ 6200. I am not quite sure why he didn't keep going to see how fast the hp dropped, but he said he used valve springs that were borderline light for a solid roller because my car is used almost always on the street. I don't like how I have to wait to like 2500rpm for the engine to "kick in" because I was used to instant torque of a smaller cam at like 1500rpm, and the car feels exactly as fast as before, but feel and track are two different things.
It's a long-rod 454 so its got the guts for higher RPMs, I want to keep it at the 6200 mark because thats what the cam swap guy told me to try to keep it near, but said my 6500rpm rev limiter is fine. He said the problem is that the engine will pull to 7500 without even hesitating, so the rev limiter is key.
A major problem here was the first run I tried I got on the gas too hard and before I even realized what happend the butt end of my car was literally in the other lane of the road and I had let off, but when I got back on it, the trans downshifed and as I gassed it, it spun to the rev limiter w/o going anywhere. I didn't hear any screeching, so I don't think it was the tires? but I honestly have no idea.
What always used to happen when I had my 1st cam (5700rpm shift points) was that I'd slam the gas, it would downshift, rip through those RPMs, shift, and keep on cooking through the next gear.
Does anyone have any idea what is going on here? Is my tranny cooked somehow? It was just rebuilt a few weeks ago, but when I floor it just downshifts and hit the rev limiter and sits there. Even without a full-throttle slam the gas down shift it does it. I don't think the tires are spinning, I don't hear the noise of them doing it, and I really doubt I make enough power to do that (440rwhp).
Did I somehow make my shift points with the governor so high that the trans can't deal with it? Or is something else going on here?
Matt
So sorry about the cross-forum stuff.
I have a turbo 400 with a gear vendors. I used the "Jake" method of 6d nails and some grinding and in 4 tries I got a good enough (actually, dead on if you ask me) for me shift governor based rpm of 6275 1-2 and 2-3, (2-3 I am pretty sure on) if I got a good enough glimpse at my tach when the 2-3 shifted. I checked the 2-3 shift @ 10am this morning after driving up and down this industrial park known for street racing three times checking for cops, then some utility workers were like "just do it!" So I warmed the tires up for them and then went down the road which is entirely too bump and ill taken care of for people to race on, (I suspect this is why they don't repave it) but I let off after the 2-3 shift because I was just checking RPMs and didn't want to go all the way to the stripe painted on the road for the street racers. Anyway... It was close-- Shift light came on (set for 6200), car shifted, light off, so I figured it was dead on.
But here is the problem, and I don't know if this is related to the governor or not. When I floor the car, it downshifts and immediatley hits the rev limiter (6500) and won't shift. This engine hits the rev limiter so easy its unreal, I don't think I ever hit the rev limiter in my hyd. roller engine, with this thing i hit it all the time and I don't know if its because something is screwed up in the trans or gear vendors or if the tires light up.. I have turned around to look for strips but never see any, but I don't know if you would be able to see strips like that. I don't think 6500 is going to hurt this rat, but I hestitate to put a higher rev limiter chip in there to see if that is whats holding it back from shifting again-- besides, even though it looked like the dyno runs could have kept going, he stopped my runs at 6200 because hp at tq had started to decline from 564hp (engine dyno) and 519/511 @ 5700/5800 to 473 ft-lbs and 559hp @ 6200. I am not quite sure why he didn't keep going to see how fast the hp dropped, but he said he used valve springs that were borderline light for a solid roller because my car is used almost always on the street. I don't like how I have to wait to like 2500rpm for the engine to "kick in" because I was used to instant torque of a smaller cam at like 1500rpm, and the car feels exactly as fast as before, but feel and track are two different things.
It's a long-rod 454 so its got the guts for higher RPMs, I want to keep it at the 6200 mark because thats what the cam swap guy told me to try to keep it near, but said my 6500rpm rev limiter is fine. He said the problem is that the engine will pull to 7500 without even hesitating, so the rev limiter is key.
A major problem here was the first run I tried I got on the gas too hard and before I even realized what happend the butt end of my car was literally in the other lane of the road and I had let off, but when I got back on it, the trans downshifed and as I gassed it, it spun to the rev limiter w/o going anywhere. I didn't hear any screeching, so I don't think it was the tires? but I honestly have no idea.
What always used to happen when I had my 1st cam (5700rpm shift points) was that I'd slam the gas, it would downshift, rip through those RPMs, shift, and keep on cooking through the next gear.
Does anyone have any idea what is going on here? Is my tranny cooked somehow? It was just rebuilt a few weeks ago, but when I floor it just downshifts and hit the rev limiter and sits there. Even without a full-throttle slam the gas down shift it does it. I don't think the tires are spinning, I don't hear the noise of them doing it, and I really doubt I make enough power to do that (440rwhp).
Did I somehow make my shift points with the governor so high that the trans can't deal with it? Or is something else going on here?
Matt