Do I need to beef up my drive train.

[AKA Speedy]

Hey everyone. I am going with a TSP 224r cam, stage 2.5 patriot heads, headers, 3" ORY and exhaust, lid, and a tune. Projected power is anywhere between 360-400 rwhp and based off a 20% drive train loss some 450-500 bhp. Someone the other day told me that stock our cars drive train is only rated for a measely 400 bhp which raises the question for me...

Is this true? Should I be concerned about a drive shaft or my rear end?

I'm not going to frequent the track and I drive like a grandpa about 5-10mph under the speed limit. However Im not going to say I won't take it out to the local 1/4 mile and see what she'll do once everything has been installed. Help me out guys....

[35th-ANV-SS]

Stock rear end breaks with stock power. A4's are less harsh on the rear than a M6 will be. Some people have better luck than others with the stock rear end, but in general, it fails for most people with moderate bolt-ons.

I would suggest start saving up for a 12 bolt or 9".

Also, what tires are you running? The stickier the tire, the worse off you will be. If you plan on upgrading the rear, I would do the DS too...as it will now be your weak link.

[AKA Speedy]

Stock rear end breaks with stock power. A4's are less harsh on the rear than a M6 will be. Some people have better luck than others with the stock rear end, but in general, it fails for most people with moderate bolt-ons.

I would suggest start saving up for a 12 bolt or 9".

Also, what tires are you running? The stickier the tire, the worse off you will be. If you plan on upgrading the rear, I would do the DS too...as it will now be your weak link.

I have an auto so yeah I figured it wouldn't be as bad on me. My tires are street tires... Firestone firehawk wide ovals. Not like drag radials...

[35th-ANV-SS]

I have an auto so yeah I figured it wouldn't be as bad on me. My tires are street tires... Firestone firehawk wide ovals. Not like drag radials...

It's basically a crap shoot IMO. You can probably make it last awhile being an A4 with street tires though....however, having all that power and just spinning the tires isn't what you really want to be doing

[AKA Speedy]

It's basically a crap shoot IMO. You can probably make it last awhile being an A4 with street tires though....however, having all that power and just spinning the tires isn't what you really want to be doing

Yeah... I just don't have the extra money to do the drive train mods yet. I'm doing all this stuff right now all at once. I just wanted to make sure if I decided to bear down on it after it was done to feel the difference that I wasn't going to break something right then and there. After talking to that guy about stuff I started looking at rear ends and drive shafts. It seems like I can get a 9" for around 1200 dollars versus 2500 for a 12 bolt. I may go on ahead and do a drive shaft now since it's only a couple hunded dollars versus a few grand

[35th-ANV-SS]

If you can get a 9" for $1200, I'd say break his leg and run off with it! A 9" is normally around 2250-2500, installing it yourself. The 9" is stronger than the 12 bolt.

[Z28boy2000]

dont forget about your tranny too. i did my cam swap then almost a year later the tranny was dying. just something to think about. it also depends on the driver...apparently i play a bit too hard. how many miles on the car?

[AKA Speedy]

dont forget about your tranny too. i did my cam swap then almost a year later the tranny was dying. just something to think about. it also depends on the driver...apparently i play a bit too hard. how many miles on the car?

Only about 65000 miles

and did you do any mods to your drive shaft or rear end before your tranny started to die?

[AKA Speedy]

If you can get a 9" for $1200, I'd say break his leg and run off with it! A 9" is normally around 2250-2500, installing it yourself. The 9" is stronger than the 12 bolt.

Yeah that's what I've been told a 9" is better, but every 12 bolt I've looked up has been solidly a grand more over the 9". I'm talking in the same sites.... Sorry I think when I said 1200 that was without the differential. This one was housing, 31 spline axles, bearings, studs, And heavy duty retainer plates.

[NoscamaroSS]

FYI, the only upgraded drivetrain parts that I have are a built tranny and stall. Everything else, including the suspension is bone stock, and I run times in the sig and have yet to have a problem. Some say im lucky, but Ive yet to break one of these rearends on my many dragstrip launches.

[Z28boy2000]

Only about 65000 miles

and did you do any mods to your drive shaft or rear end before your tranny started to die?

Nope it was all stock, but i had 135k on it when i did the swap...so im pretty sure miles played a factor too.

[35th-ANV-SS]

I put my Moser 9" in along with my LCAs, Torque Arm, PST DS, and SFCs all at once. Two weaks later my transmission synchronizer keys broke so I ended up sending it to get built by RPM. It was an expensive summer

I am at 330rwhp and 342rwtq on a Mustang DYNO. When I swapped out my 10 bolt for the Moser at 12K miles on my car, the differential was leaking a little already.

[AKA Speedy]

ugh... I think I'm going to get a drive shaft safety loop for now until I can afford to do any other mods to the drive train. Hell who knows I might be a lucky one and not have any problems.

I was planning on doing a gear swap, but I'll probably hold out on that encase I do grenade the rear end. Then that's $400 I can put towards a 12 bolt or 9"