Horsepower axles transmission strength

[4wheelspin]

How much horsepower and torque could a WRX transmission and FFR axles take before they let go?

[Canadian818]

Only one breakage so far. 340hp, slicks, 3rd gear failure.

[07FIREBLADE]

We also don't really know the condition go the trans prior to install and usage. So it may be able to take more... But to be safe 300 will most likely be reliable on a 06+ trans and mid to high 200s for 02-05. Lgt trans may take more or the same as the 06. And we will soon have the sti trans to play with.

[BrandonDrums]

We also don't really know the condition go the trans prior to install and usage. So it may be able to take more... But to be safe 300 will most likely be reliable on a 06+ trans and mid to high 200s for 02-05. Lgt trans may take more or the same as the 06. And we will soon have the sti trans to play with.

I for one happen to be somewhat confident that the 5mt will be able to handle a bit more power in the 2wd lightweight setup in the 818. I have over 350 whp and tq in my 05 wrx and well over 100,000 miles on the original transmission with no issues.

The secret I've used is the tinyrex 'launch control' patch for the ECU. All its doing is setting a 2 stage rev limit. At 0-3mph (you can set the range) my rev limiter is set to 3700 rpm. I can floor it and the engine won't go over that. It's where I get spool and it's just below where I make the max torque. Due to the much lower engine speeds I don't shock load the transmission on drop as much.

http://www.ecu-mods.com/online/index...iewCat&catId=6

That being said, I do believe that the lower weight of the 818 will increase the margin for failure on the 5mt's. In addition, the gearing for the 5 speed is so much more appropriate for the 818. The 6mt's gears are a bit too short. You'll spend more time shifting than going.

Perhaps a 6mt with a final drive swap would be best.

[07FIREBLADE]

I agree with you Brandon. It really depends on the build and the driver to be honest. My 06 is at the same level your 05 is at and I do not have any tranny issues. I personally can't afford to break anything since it's still being paid off. But if you drive the car like you stole it no matter what trans that happens to be in it will be prone to failure. The 5sp is definitely geared better it's just not as strong unfortunately.

[Joe Scott]

hey guys just some food for thought, on our R model, we had custom chromoly half shafts made. this, with the race slicks, were the reason all of the stress went into the transmission for hammer time. if we didnt have slicks on, the tires would have spun, if we didnt have the chromoly shafts, chances are those would have broke. we are not expecting to have issues with using the 5MT if you go stock with the kit. if you plan on beefing up TQ and HP numbers, you will obviously want to make the safety precautions of the other items delivering said power. Joe@FFR

[fateo66]

hey guys just some food for thought, on our R model, we had custom chromoly half shafts made. this, with the race slicks, were the reason all of the stress went into the transmission for hammer time. if we didnt have slicks on, the tires would have spun, if we didnt have the chromoly shafts, chances are those would have broke. we are not expecting to have issues with using the 5MT if you go stock with the kit. if you plan on beefing up TQ and HP numbers, you will obviously want to make the safety precautions of the other items delivering said power. Joe@FFR

So...can we buy those fancy chromoly shafts too?

[SixStar]

As someone who has killed an RA box with only 260/260 there's always a weak link, these days I chose to make it my clutch. No issues so far, only cost me two transmissions to learn that lesson.

[fateo66]

Alot of it IMO is how you drive it. I know multiple people running 400-450 WHP on a stock 5mt but they actually release the clutch instead of just dropping it. However on the flip side I also know of a bunch of people who have destroyed several transmission on stock power because they just slide their foot off the clutch pedal sideways.

[Lou]

Alot of it IMO is how you drive it. I know multiple people running 400-450 WHP on a stock 5mt but they actually release the clutch instead of just dropping it. However on the flip side I also know of a bunch of people who have destroyed several transmission on stock power because they just slide their foot off the clutch pedal sideways.

Yes I can vouch for this. Im in the mid 400s and my 5 spd was holding up. Granted, it was upgraded with LGT gears. And i switched from 6 puck clutch to a full disk.

[rtz]

So...can we buy those fancy chromoly shafts too?

Try some of these:

http://www.driveshaftshop.com/import-axles/subaru

[SixStar]

Our's are already custom.

I can't see DSS retooling for a production run of 40 axles, even at their bargain prices of $500 per axle.