spare tire & drag racing Q

LaZy4zNbOi · 09-07-2003, 02:36 PM

I was told by the dealership to remove a fuse when i use the spare tire so i don't screw up the differentcial. that way it makes the car FWD instead of AWD. If we were drag racing would we go faster if we had it AWD or FWD? I imagine FWD would give us a slower start but a faster time. AWD will give us a faster start but a slower time. Any inputs?

crazytrain · 09-07-2003, 02:53 PM

I really don't see how that could help. 2wd cars have less drivetrain loss because they have less drivetrain. Just becayse you don't actually turn 2 of the wheels doesn't mean that you have removed any loss from the drivetrain. On the contrary, you lose the ability to put power to the pavement at all possible points. The only possible thing you might help would be the cluth or tranny by being able to spin the tires on the launch. Of course, that's a big speed loss compared to what you get with the AWD.

I would check in the manual anyway, just to double-check what your dealer is saying. It sounds fishy that a fuse could have all that much impact on your differentials. Plus, the spare is nearly the same diameter as the stock tires, which minimizes the negative impact on the differentials in the short period of time that you should ever use it.

***MKIVSupra*** · 09-08-2003, 06:16 AM

I believe that fuse is only used for cars with automatic trans. Do we even have a fuse like that? I neve looked.

Hank__Scorpio · 09-08-2003, 07:45 AM

FWD sucks for racing. First theres the fact that when your car is accelerating the weight naturally shifts back, lessening the amount of weight pressing the front (driving) tires to the ground. Second, torque steer would be worse with FWD than AWD. Plus AWD is just more fun.

Xman · 09-08-2003, 07:50 AM

Quote:

Originally Posted by MKIVSupra

I believe that fuse is only used for cars with automatic trans. Do we even have a fuse like that? I neve looked.

There is no electrical way to make the STi a fwd car. the only way to do this is to physically remove the propeller shaft (driveshaft) that goes to the rear differential.

CloNeGTS · 09-09-2003, 06:01 AM

What the heck kinda question is this???

You might be told to remove the fuse for the DCCD when using the spare so that the differential stays open, but I don't even see the need for that. The spare is full sized. I still don't think it would be a good idea to throw the diff in full lock with the spare on, but.....

What would using the spare and FWD have anything to do with each other??? I'm baffled by this one....

***MKIVSupra*** · 09-09-2003, 06:09 AM

All Subarus with an automatic trans come with a place to put in a fuse that puts the car in FWD mode. You are suppose to use this when using a spare and maybe for other reasons, I don't remember. Subarus with manual trans do not have this. I think it is something to do with manual trans subarus being more of a mechanical AWD system and automatics not. My old automatic Legacy had a power split of I think 90 front 10 rear until it sensed slipping, then it would transfer the power. Manual trans have a 50/50 power split all the time. I am pretty sure the STi has no such place for a fuse that is why I was wondering why the salesman said to do that.

SnowbordrWRX · 09-09-2003, 11:50 PM

Quote:

Originally Posted by CloNeGTS

...The spare is full sized...

Really??? I always thought the STi had a donut?

CloNeGTS · 09-10-2003, 04:59 AM

yeah....didn't say that quite right. Full sized as in it is big enough to clear the calipers and it is the proper running diameter. Not full sized per say....

09-07-2003, 02:36 PM	#1
LaZy4zNbOi Junior STI Driver Posts: 136 IWSTI Addict since: Sep 2003 Trader Rating: (0)	I was told by the dealership to remove a fuse when i use the spare tire so i don't screw up the differentcial. that way it makes the car FWD instead of AWD. If we were drag racing would we go faster if we had it AWD or FWD? I imagine FWD would give us a slower start but a faster time. AWD will give us a faster start but a slower time. Any inputs? This ad is not endorsed by this member. Please register or login to hide this ad.

09-10-2003, 04:59 AM	#9
CloNeGTS S204 Racer Car: Solo II, WRC Location: Overland Park, KS Posts: 2,776 IWSTI Addict since: Oct 2002 Trader Rating: (1)	yeah....didn't say that quite right. Full sized as in it is big enough to clear the calipers and it is the proper running diameter. Not full sized per say.... This ad is not endorsed by this member. Please register or login to hide this ad.

New To Site?	Need Help?	More
REGISTER FOR FREE! IWSTI Rules/Signature Rules Create a Member Journal Bookmark IWSTI Tell your friends about IWSTI	Frequently Asked Questions Did you forget your password? Make a suggestion or report a bug Mark Forums Read Contact Us	Member Journals Forum Pictures & Photography Forum GR Series (08+) Marketplace GD Series (03/04-07) Marketplace Hot eBay Deals Forum Beyond Off Topic

09-07-2003, 02:53 PM	#2
crazytrain Senior STI Driver Location: Kansas City Posts: 348 IWSTI Addict since: Mar 2003 Trader Rating: (0)	I really don't see how that could help. 2wd cars have less drivetrain loss because they have less drivetrain. Just becayse you don't actually turn 2 of the wheels doesn't mean that you have removed any loss from the drivetrain. On the contrary, you lose the ability to put power to the pavement at all possible points. The only possible thing you might help would be the cluth or tranny by being able to spin the tires on the launch. Of course, that's a big speed loss compared to what you get with the AWD. I would check in the manual anyway, just to double-check what your dealer is saying. It sounds fishy that a fuse could have all that much impact on your differentials. Plus, the spare is nearly the same diameter as the stock tires, which minimizes the negative impact on the differentials in the short period of time that you should ever use it.

09-08-2003, 06:16 AM	#3
*MKIVSupra* Moderator Elite Car: 04 Subaru WRX STi, W Fav Mod: KartBoy SS & Bushings Location: Illinois Posts: 8,746 IWSTI Addict since: Jan 2001 Trader Rating: (0)	I believe that fuse is only used for cars with automatic trans. Do we even have a fuse like that? I neve looked.

09-08-2003, 07:45 AM	#4
Hank__Scorpio Amateur STI Driver Location: Rochester, NY Posts: 15 IWSTI Addict since: Sep 2003 Trader Rating: (0)	FWD sucks for racing. First theres the fact that when your car is accelerating the weight naturally shifts back, lessening the amount of weight pressing the front (driving) tires to the ground. Second, torque steer would be worse with FWD than AWD. Plus AWD is just more fun.

09-09-2003, 06:01 AM	#6
CloNeGTS S204 Racer Car: Solo II, WRC Location: Overland Park, KS Posts: 2,776 IWSTI Addict since: Oct 2002 Trader Rating: (1)	What the heck kinda question is this??? You might be told to remove the fuse for the DCCD when using the spare so that the differential stays open, but I don't even see the need for that. The spare is full sized. I still don't think it would be a good idea to throw the diff in full lock with the spare on, but..... What would using the spare and FWD have anything to do with each other??? I'm baffled by this one....

09-09-2003, 06:09 AM	#7
*MKIVSupra* Moderator Elite Car: 04 Subaru WRX STi, W Fav Mod: KartBoy SS & Bushings Location: Illinois Posts: 8,746 IWSTI Addict since: Jan 2001 Trader Rating: (0)	All Subarus with an automatic trans come with a place to put in a fuse that puts the car in FWD mode. You are suppose to use this when using a spare and maybe for other reasons, I don't remember. Subarus with manual trans do not have this. I think it is something to do with manual trans subarus being more of a mechanical AWD system and automatics not. My old automatic Legacy had a power split of I think 90 front 10 rear until it sensed slipping, then it would transfer the power. Manual trans have a 50/50 power split all the time. I am pretty sure the STi has no such place for a fuse that is why I was wondering why the salesman said to do that.