The problem is both are to small. unless I get a racing lockup and all billet overdrive components. Even then, it is sketchy.

10,000 rpm is a little fast, If it were shorter I should be o.k. though.

It's going to take more than 1k hp to run 200 with the weight of your car,but thats been dicussed before,build it for abuse is the onlt way it will hold,If run a race tranny fuild that has a high temp rating it shouldn't boil at all.

i had just shy of 7k in my 4l80e,convertor,controller and all,the tranny was as bulletproof as you build right now

Looking like the 4l80 is way out of the budget right now. I have been getting lots of trade offers for T56's, so that is what I might do.

My car has WAY more power then it needs to do 200 mph. In the standing mile, I may only get to 195 or something on pumpgas, but thats fine with me on 93 octane. That will make me happy.

If this brick (picture below)will do 188 with the supercharger belt flipped over 9 seconds from the finish, I feel confident I can do close to 200 also in the standing mile. I could always put race gas in and run way over 200 mph in the standing mile, But I would be happy just to try a 93 octane run at it!

http://i8.photobucket.com/albums/a50.../Stevescar.jpg

I have a 4L80E in my pick up truck and it holds wot in 4th for freeway blasts. The longest one involved a AMG benz and was under 20 seconds. My engine makes 900ft lbs and 800hp at full boost and the trans has been great. I have burned up a few converter clutches in short order locking at wot. I now don't lock anytime above 70% throttle just to be safe.

Kurt

Top speed?

interesting picture of the Ford Granada. Who's car is it as I don't recognise it as being a 188mph car?. The car's British & is photographed at Santa Pod in Bedfordshire & is street registered. To be running 188mph it would be the quickest street legal car out there as the quickest street legal car is this:-

http://209.85.135.104/search?q=cache...ient=firefox-a
hope that helps ;)

didn't you say you have not even gone 155 as of now, but you know it will???? kinda jumping alittle quick.
also 200 mph and budget should not be used in the same sentence.

btw, for top speed i wouldnt use an OD tranny, there is a small but significant powerloss in any transmission, and with slant cut gears it will be in the 5% range in 6th. gear.. with 1000 Hp churning through tour transmission, you are generating 50Hp or 36KW if heat in your tranny... not to mention loosing 50 Hp that could propell you to go faster.... if top speed is your only goal .. try and find a liberty 4 speed with straight gears from a nascar chop shop.. there are a bunch of them on ebay

i am not sure about the aerodynamics of a 70 chevelle, but with a small nascar wing to atleast keep the rear end from lifting (if you dont do bonneville style holes in the decklid) 200 mph should be reachable with yuour 800 rwHp.. (it will do 100 mph with 200 rwHp easy!)

but you are putting an enormous strain om your parts running WOT and big load for long periods... your turbos will be RED hot, perhaps ypu should run some water injection just to keep the combustion temperature within a reasonable range

i still say that a 4l80e with lockup should get you there.. and if you only break 190mph??... i have a feeling you would up the boost 5 or 10 lbs and try again?? correct?

My speedometer quits at 120 so I am not sure. I have run 5000 rpm in overdrive many times. It goes into overdrive just after the 1/4 mile mark (about117). My guess is over 130 for sure, possible over 140. I am sure it will run over 140 in a mile, so I don't take it to Maxton as it has no rollcage.

Kurt

Overdrive is very common in land speed cars although it would be nice if we did not need it. The car I drive has a Jerico 4 speed trans. The first two gears are normal, when you put the shifter into third you are one to one (trans fourth), when you put the shifter into fourth the trans is in what we would call third, it is geared .85-1 for the overdrive. Some cars run a one-one box with a overdrive on the back that shifts once or some use the over as a splitter.

Kurt

Very interesting reading and completely out of my league!!

But don't the big M/B cars run 1 to 1 and get the equivalent of OD by using really high rearend gears for the same overall affect except no problems with driveshaft over-rpm'img?????

And that's why they do it...............

pdq67

Well, luckily I will not be overspeeding my driveshaft. It has a critical speed the way it sits of about 10,000 rpm and if shortened for an overdrive, would go to over 12,000 rpm+.(3.5" Aluminum MMC).

That Granada is from Ireland and has a top speed of more then 188 mph. That's just what he did in the standing mile from a dead stop to a 1 mile marker. If he did not run into belt issues I am sure he would have been real close to 200 mph. Pretty good for a 3600 lb barn door either way! :)

Boy, sounds like the 4l80 might handle the power, but would need 5k invested to last. I would be real worried about a stock trans and how it would last for the time being. A T56 setup will not cost a thing if I trade my current setup even up for one, but I have to rebuild it once a year with real heavy beatings. I will also take much more time for a swap. I already have a pedal set, but will need to do some tunnel work and get the clutch setup installed and working correctly. Plus, my wife can't drive stick, so that is another bad factor.

I guess I will keep looking into both options for now and try to make a choice sooner or later.

Thanks for all the input.