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final gear 1/4 mile finish in a t56???


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im just curiouse what gear do you t56 guys finish the 1/4 with...my 1st gear climbs and spins tires without even reving...the rpm clibs way too fast. im cruising on the highway in 6th at 3800-4000k rpm at 75-80mph. i think thats a little high isnt it? if i leave it in 5th, its at 5000-5500k at 70-75mph... the car for some reason idles at 1500k. hasnt been tuned yet though but i was just curiouse cause it doesnt feel too fast to me.

i have the lt4 cam with 1.6rr. and lt4 springs. im going to say it redlines at 6400k. my r200 is a 3.90...what do you guys think?

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I'd check the tach and the rear end gearing first.

 

Justin

 

I agree. My car runs at 2000 rpms in sixth at around 85MPH. I have a 3.54:1 rear ratio and a .50 6th gear. I run 225-50-16 tires.

 

You should be able to tell approx. how fast you are turning the motor at 4000 rpms by how loud it is.

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im just curiouse what gear do you t56 guys finish the 1/4 with...my 1st gear climbs and spins tires without even reving...the rpm clibs way too fast. im cruising on the highway in 6th at 3800-4000k rpm at 75-80mph. i think thats a little high isnt it? if i leave it in 5th, its at 5000-5500k at 70-75mph... the car for some reason idles at 1500k. hasnt been tuned yet though but i was just curiouse cause it doesnt feel too fast to me.

i have the lt4 cam with 1.6rr. and lt4 springs. im going to say it redlines at 6400k. my r200 is a 3.90...what do you guys think?

 

Something is very wrong. Don't know if the tranny gears are right but still......To get 5500 prm at 75 in 5th with a 3.91 you'd have to be running a 13.5 inch tall tire.

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maybe my tach is off??? and the pcm for sure needs to be retuned. when i shift at 6500k, it hits pretty hard in all the gears like its suppose to, or maybe it can hit even harder? the tach is an autometer 5inch tach suposedly made for 4-6-8 cyl vehicles. it idles at 1500k but the motor sound like its at 7-800rpm. you can hear its not too high but then again, its my first v8 so im not too sure either. my tires are 225-55-16 rears and 205-55-16 fronts. the rpm on this thing just jumps so fast that it looks like im not getting all the hp out of the gears. im running a t56 from a 95 lt1 camaro. the rear end is off of a 82zx with 3.90 gears. im not sure its the diff because it wasnt so high with the stock datsun 5spd. believe it or not, in 5th on the highway, it sounds like its high in 5th, just the sound, its almost believable the rpm is correct. but i have no carpet so the sound is extremely loud, its just bare floorboards and that also interfears. to think of it, it almost sounds like ill be done with the 1/4 mile in the end of 5th gear. sounds like the cars going to fall appart @ 90mph and its also a negative feeling and ill put it into neutral for my own safety. ill be checking into the tach and looking into purchasing tuner cat...thanks for all response...

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I don't think your tach is wired up right or you've got it set on 6-cyl or 4-cyl idling at 1500 is awfully high especially in something with some decent cubic inch and small blocks don't normally rev extremely fast though their are exceptions but my bet is still on a tach issue hope you get it fixed.

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Well the T56 in my car is from a 1993 so the 6th gear is .62:1. I have 25.3" tires and a 3.54 rear end. I am also runnin the LT4 hotcam kit and running it out to 6500 rpms is just asking for floating a valve. I dont rev mine past 6200 at most but usually shift at 6000 when really on it. You aren't making any more power up there anyways.

 

At 75ish I'm in the 2200rpm range. 1500 RPM's at idle is possible, no vacuum leaks on the intake ports right? Back down your throttle body adjuster screw if its cranked all the way in that should help your idle. My car idles at about 900rpms and if I hold it at 1500 rpms its pretty loud and sounds like its really turning some rpms just for an idle speed. I would think you would notice a 1500 rpm idle. I also have the 5" tach from autometer(phantom series) and I could see that little switch on the back being set wrong pretty easy. That's what I would check first.

 

Guy

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