Heavy E body maximum HP for 8 3/4 rear axle - Moparts Forums

Register Log In Moparts Forums Corners Are Best - Handling Tech Heavy E body maximum HP for 8 3/4 rear axle

Print Thread

Heavy E body maximum HP for 8 3/4 rear axle #1664551 08/28/14 12:06 AM 08/28/14 12:06 AM
Joined: Nov 2005 Posts: 3,456 Fly Over States P PHJ426 OP master
PHJ426 OP master P Joined: Nov 2005 Posts: 3,456 Fly Over States	In a big block E body for street and some high speed driving events what is the maximum HP you would toss at an 8 3/4 rear end. This should be a lot more than an all out drag car leaving the line of a dragstrip treated with VHT and slicks on the car. Currently there is a Dana in the car and shedding it for an 8 3/4 will save some weight but is the trade off in HP capability worth the extra weight in the rear of the car? 8253529-SCAN0035.JPG (55 downloads)

Re: Heavy E body maximum HP for 8 3/4 rear axle [Re: PHJ426] #1664552 08/28/14 10:29 AM 08/28/14 10:29 AM
Joined: Jan 2009 Posts: 813 Ontario,Canada brads70 super stock
brads70 super stock Joined: Jan 2009 Posts: 813 Ontario,Canada	I don't know the answer to your question but I went with DrDiff (strange S60) because it was lighter than an original Dana and I get everything new , upgraded taper roller bearings, truetrac etc... Sold the 8 3/4 before I owned 2 of them....

Re: Heavy E body maximum HP for 8 3/4 rear axle [Re: PHJ426] #1664553 08/28/14 11:14 AM 08/28/14 11:14 AM
Joined: Dec 2003 Posts: 22,696 Bitopia J jcc If you can't dazzle em with diamonds..
jcc If you can't dazzle em with diamonds.. J Joined: Dec 2003 Posts: 22,696 Bitopia	I don't think anybody posting here can exceed the power capability of a well built 8.75 in a road race environment, and if they did, they would be at the top of the list for bragging rights. The original twin turbo Cuda in "projects" forum would be an exception. Big Sticky tires, upgrade/optimized suspension, some aero, and big motor for salt falt runs would IMO start to reach the limits. And a 8.75 vs most others saves a few hp in friction losses and at that level might be important. Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.

Re: Heavy E body maximum HP for 8 3/4 rear axle [Re: jcc] #1664554 08/28/14 11:25 AM 08/28/14 11:25 AM
Joined: Jan 2007 Posts: 780 Woodinville, WA Viol8r super stock
Viol8r super stock Joined: Jan 2007 Posts: 780 Woodinville, WA	Quote: I don't think anybody posting here can exceed the power capability of a well built 8.75 in a road race environment, and if they did, they would be at the top of the list for bragging rights. The original twin turbo Cuda in "projects" forum would be an exception. Big Sticky tires, upgrade/optimized suspension, some aero, and big motor for salt falt runs would IMO start to reach the limits. And a 8.75 vs most others saves a few hp in friction losses and at that level might be important. I am at 550hp+ with plenty of road course and autocross time. Stock everything, taper bearings. No issues in 5 years of hard running. 1968 Pro-Touring Dodge Charger *2011 Optima Ultimate Street Car Challenge Invitee http://www.popularhotrodding.com/features/1203phr_1968_dodge_charger/index.html

Re: Heavy E body maximum HP for 8 3/4 rear axle [Re: PHJ426] #1664555 08/28/14 02:30 PM 08/28/14 02:30 PM
Joined: Jan 2003 Posts: 5,388 Pikes Peak Country T TC@HP2 master
TC@HP2 master T Joined: Jan 2003 Posts: 5,388 Pikes Peak Country	My drag car was 400+ hp, launching at 4200 rpm with slicks, 4:30 spool rear in an 8.75 rear. No issues in the decade I ran it. For a higher powered engine on a road course, it should be no big deal as the shock loading of dumping a clutch is whats hard on them. Way back when, dragster were pushing 800+ horsepower through them and the Olds equivilent. Of course they were cut down to be no wider than a few feet, and they smoked the tires the entire quarter mile. IMO, the 8.75 Banjo rear is pretty stout for most applications. Even the maligned 741 units have a larger pinion shaft than a number of other brands rear ends.

Re: Heavy E body maximum HP for 8 3/4 rear axle [Re: TC@HP2] #1664556 08/28/14 03:11 PM 08/28/14 03:11 PM
Joined: Nov 2005 Posts: 3,456 Fly Over States P PHJ426 OP master
PHJ426 OP master P Joined: Nov 2005 Posts: 3,456 Fly Over States	The current engine I have currently built for the Challenger is 512 RB stroker 4.25" crank 13.5 cr B1BS cylinder heads mechanical cam from my friend Scott Brown. Engine was built by the late Kenny Stafford funny car driver. I still remember when he called me with the dyno results from breaking the engine in. It made 700 flywheel hp. Granted I have become bored with drag racing. I enjoy driving the cars and not waiting around all day. Ill probably pull some compression out of the engine and knock a little power out of it. Might get it down to 650?

Re: Heavy E body maximum HP for 8 3/4 rear axle [Re: PHJ426] #1664557 08/28/14 10:44 PM 08/28/14 10:44 PM
Joined: Nov 2005 Posts: 3,456 Fly Over States P PHJ426 OP master
PHJ426 OP master P Joined: Nov 2005 Posts: 3,456 Fly Over States	Talked with Scott Brown today about pulling the CR down to pump gas levels around 10.75....he says with the correct combination of parts this engine will be still around 700HP.....guess I will keep the Dana rear end in the car. Next thing I need to figure out is if I will keep that 727 or go with a T56 so I can then calculate what rear axle ratio to run in this heavy barge....

Re: Heavy E body maximum HP for 8 3/4 rear axle [Re: PHJ426] #1664558 08/29/14 03:47 PM 08/29/14 03:47 PM
Joined: Jan 2003 Posts: 5,388 Pikes Peak Country T TC@HP2 master
TC@HP2 master T Joined: Jan 2003 Posts: 5,388 Pikes Peak Country	Don't overlook the possibility of using methanol injection. Snow Performance makes a nice unit that can use windshield washer fluid.

Re: Heavy E body maximum HP for 8 3/4 rear axle [Re: TC@HP2] #1664559 08/29/14 04:16 PM 08/29/14 04:16 PM
Joined: Nov 2005 Posts: 3,456 Fly Over States P PHJ426 OP master
PHJ426 OP master P Joined: Nov 2005 Posts: 3,456 Fly Over States	I was also hashing over the idea of running E85 since there is so much of it here in Illinois. It appears problems arise if the car sits for long periods of time. I am going to get Scott the build number for the pistons and we will see if there is enough to give the pistons a haircut to drop the compression down a few points. The head gaskets are Cometic and a thicker gasket can be used but its $$$$. Who knows maybe a 200TW tire will hold the power coming out of a corner? If not there are stickier tires out there to allow for more throttle.

Re: Heavy E body maximum HP for 8 3/4 rear axle [Re: PHJ426] #1664560 08/30/14 12:27 AM 08/30/14 12:27 AM
Joined: Jan 2009 Posts: 813 Ontario,Canada brads70 super stock
brads70 super stock Joined: Jan 2009 Posts: 813 Ontario,Canada	Quote: Who knows maybe a 200TW tire will hold the power coming out of a corner? If not there are stickier tires out there to allow for more throttle. Don't count on that. I have a somewhat healthy 451"(550ish HP) and 615k's and I can still steer with the throttle if I want. I've run water injection before, works great. In the winter I added in isopropyl alcohol to keep it from freezing. There was no doubt when the water tank was empty.

Re: Heavy E body maximum HP for 8 3/4 rear axle [Re: brads70] #1664561 08/30/14 12:43 AM 08/30/14 12:43 AM
Joined: Nov 2005 Posts: 3,456 Fly Over States P PHJ426 OP master
PHJ426 OP master P Joined: Nov 2005 Posts: 3,456 Fly Over States	I prefer not to rely on alcohol and water injection to keep the engine from pinging and knocking. It's going to be a blast that is for certain.

Re: Heavy E body maximum HP for 8 3/4 rear axle [Re: PHJ426] #1664562 08/30/14 08:34 PM 08/30/14 08:34 PM
Joined: Jan 2003 Posts: 5,388 Pikes Peak Country T TC@HP2 master
TC@HP2 master T Joined: Jan 2003 Posts: 5,388 Pikes Peak Country	Quote: I was also hashing over the idea of running E85 since there is so much of it here in Illinois. It appears problems arise if the car sits for long periods of time. I thought about the E85 route, but...if I drive much outside of my immediate geographic area, I run the risk of not being able to find it or getting diluted mixes down around E75. Its much easier to find washer fluid anywhere you drive than it is to nail down good E85, so I went injection instead. Then again my engine was all together and swapping out pistons was not a consideration I would make.

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer, tommoparts

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1