8.8 Power Limits

to be clear, the 8.8 in it is already braced and setup well and running mid 5's, looking for some
examples of people running in the high 4's on a 8.8.

We have a customer that runs 4.70's with an 8.8 in a 2920lb car on a radial that goes 1.08-1.10 every pass.  We have to put gears in every 30 or so passes to make them live.  I'll post pictures of the bracing on it.

It likely has to a lot to do with the safety margin of it, who want's to risk wrecking at those speeds to save a few bucks on the rear end.

supervel45 wrote:It likely has to a lot to do with the safety margin of it, who want's to risk wrecking at those speeds to save a few bucks on the rear end.

What would break on a built 8.8 that would wreck you that wouldn't wreck you with a 9"?

I would suspect the pinion gear would let go first on a 8.8". If it does, I don't see that being a good thing, especially if the car is loose when it happens by chance, like some of the no prep pedal fest races.

Alex Hayes is a n/a BB guy and said he was breaking the pinion gear

and thats why you upgrade to a 9"

Yeah that's the hole point of this post lol

The 8.8 will live with serious power but you will have to stay on top of the maintenance to keep it happy... just like anything else hi-performance. The question is how often do you want to down it and check on parts

He puts rear ends in a unique situation that most on this site dont see: rpm.

I was really thinking structurally but I see your point about the gears. We get about the same use out of 8.8 gears and small pinion 9" gears. If I was building a rear end fo a car running faster than 5.20's or so it would have a big pinion 9". It'll last a long time. For heavy radial cars running deep into the 4's id run 9.5" gears. Cars on slicks can run 9" gears forever it seems.

I tune a car for a friend with an 8.8" in his Fox. When it was a high to mid 5 sec. car all was well....pretty much normal life for a raced 8.8". Now that it's a 5.0 car, soon to go 4.90's, the pinion gear climbs the ring gear and occasionally comes out looking like a chicken leg. He's fixing the 8.8 one last time and shopping for his 9" now.

Marcus Warwick is building me a chromoly fabricated 9 inch

Here's the junky ole 9" housings we put out. This one is in a mopar if you are asking about the backwards shock brackets.  Custom jig built fabricated housings.  Jig itself is pretty cool but we're not posting pics of it.  

https://www.facebook.com/2JMFab/photos/a.967041470003473.1073741846.416404781733814/967041656670121/?type=3&permPage=1

https://m.facebook.com/groups/1525133584437397?view=permalink&id=1671482023135885
This is my new rear end

We have an 8.8 in our car that is built and braced. 35 spline axles and 9" ends. Car has been mini tubed. The car weighs 3250 lbs and we run a turbo 400 and also a pg. Best so far has been a 4.90 @ 146.8, with nitrous. This is a BBF combination. We have broke one gear, that was a 4.30 ratio. In talking with others for some reason the 4.30s break. We have not had any problems with 3.73, 3.90, or 4.10. We have run 275 drag radials as well as 28 x 10.5 slicks.

Also know someone that runs nitrous x and/or ultra street with an 8.8 and runs 4.70s-4.80s with a nitrous sbf set up.