Balance of AWD's

[gsxeclipse97]

Ok i searched but i couldn't find anything that showed what i was looking for. My friend bought a 2007 350z and he was telling me that because the car was well balanced that it would out handle my car. he said that his car was 51% in front and 49% in rear with out driver. I couldn't find the weight distrubiton on our car's but from what I remember awd cars will always out handle a rear wheel. so the question is what is the weight balance on the 97+ cars?

 

[Talesin]

Uh, yes. Part of relocating the battery is securing it. :b Generally a sealed battery box with a vent tube for those that want NHRA/SCCA tech approval... I just went with an Odyssey dry cell and one of their custom battery boxes with clamp down ears. Wouldn't be any fun to have 30 pounds of battery saying hello to the back of your head during emergency braking down from 70-ish.

FWDers will want to keep the battery up front to help reduce wheelspin. For a GSX, it creates a decent difference in feel, especially if you already have upgraded your suspension. The car turns noticeably more easily and smoothly, both on turn-ins and while holding a line. Awesome mod for AWD guys, though it may feel a little 'squirrelly' at first, like you're on the edge of understeer, until you get used to how the car responds all over again.

 

[eldiabloz13]

I see everyone talks about a vent tube but what is it. Whats its place on that mod.

 

[nightspeed87]

I own fwd and awd dsms, and the awd is much more stable at all times than the front wheel drive... The front wheel drive to me sucks, I just hydroplaned it off the road yesterday ( it was raining) when turning around a long curve at 30mph with good new tires on. 2nd time thats happened since I owned the car ( 2years.) It basically kept going straight even though the steering wheel was facing the other way, and luckily I didn't hit a sign that was 3 feet away...

Also I cant boost into a turn ever without a high possibility of losing control on the front wheel drive were as all the awd dsms Ive drove can take a corner hard in 2nd gear full boost...

Not to mention the lack of traction on 1st and 2nd gear with the fwd at full throttle.
It could really use a lsd badly and better suspension upgrades to be truly safe.

The only advantages to fwd over awd dsms
weight difference, gearing feels better on fwd, and less drive train lose...

Other wise awd dominates...

( This isn't a good comparison between my two dsms considering my fwd has almost stock suspension set up
and my awd 1g has a rather "tuned" suspension set up *( can see awd mods in profile.)

To the op, the 350z will out handle you ( given wt balance and other stuff etc mentioned above ) and dsms were made in early 90s vs the new Z suspension which is more modern and set up to perform vs a old school dsm set up. Stock for stock, the z will carve circles around a dsm in the twisties given proper drivers.

Just my 2 cents though.

 

[Talesin]

A vent tube is a piece of tubing that goes from a sealed battery box to the outside world, usually just through a hole drilled down through the floor of the trunk, or one of the drain plugs. It's to allow the battery in the box to 'off-gas' safely to the outside world when it gets charged higher than a certain voltage (13.7v IIRC) an overcharging condition. If there was no vent tube, the battery would still off-gas, but the gasses would build up inside the sealed battery box, potentially popping the seal and sending all those wonderfully hazardous-to-your-health fumes into the cabin air. Same thing that happens when people don't bother to box their battery, and just secure it in the trunk, and have their alternator fail into overcharging mode. Not Good to breathe that stuff.
I have a dry cell battery (Odyssey 925), which doesn't EVER off-gas. Sadly the NHRA/SCCA rules are so archaic that if I want to pass tech, I still will need to shell out for a vented battery box and install it according to regs. Craptastic!


I'd love to get a GS-T again for DD use. The gearing is so much longer, it's a lot more fun on the freeway, and gas mileage is TONS better. But for technical/'fun' driving, it'd still take the back seat compared to the GSX.

 

[eldiabloz13]

Thank you for that i was going to buy a box that didnt vent. You saved me a good couple bucks.

 

[Talesin]

Moroso seems to be the one most people use. It's a little expensive, but it's worth it given that it passes tech perfectly, and has been reliable for many DSMers.

http://www.rpmoutlet.com/musv6batt.htm

 

[nightspeed87]

Moroso seems to be the one most people use. It's a little expensive, but it's worth it given that it passes tech perfectly, and has been reliable for many DSMers.

http://www.rpmoutlet.com/musv6batt.htm

Hmm... Yea I did it the cheap way and just got a 6 dollar unsealed battery box from walmart. Guess im going to be breathing gases for now... This definitly is a considerable thing to do for the future though. Or I can seran wrap the top to seal it and make a vent tube .... j/p

 

[GSX26]

Nevermind, I just searched it, the split is 50/50.

Not on a stock DSM... only with a welded center diff or an aftermarket center diff

 

[Dragon TalonTsi]

^^^^ Double check your sources GSX26...
Its a 50/50 Split for power distribution... I saw this in another thread and saved it. Of course, when the LSD kicks in, its a bit different. Credit goes to where its deserved...

 

[hi_psi_dsm07]

Not on a stock DSM... only with a welded center diff or an aftermarket center diff

Do a search of "power distribution" It's 50/50, even stock.

 

[dsm-onster]

One reason why guys go to a welded diff is because it takes TIME for the viscous coupling to lock. Welding the diff ensures that the axles are locked before any slippage between the front and rear.

 

[GSX26]

My bad, I always thought the front had more of the power and the rear got more as the tires slipped... Thanks for correcting me guys

 

[Talesin]

Would be nice to get a 35/65 (or 30/70) split to take some of the accelleration traction load off the front tires, but it doesn't seem to be in the cards for our cars. :b

 

[gsxeclipse97]

Well.. Its a nice setup as far as that goes.. but i would really like to have an active center diff like the evo 9 I think that would greatly improve our handling

 

[Nors]

Off topic, WOW that batter relocation kit is expensive!

 

[gsxeclipse97]

Yeah but if they are that helpful I will be getting one soon as my car is up and running

 

[Talesin]

Depends on what you're going with for the relocation. That kit is good if you want to pass SCCA tech without the inspector batting an eye. If you want to do it on the cheap (or with a smaller battery) it *can* be less expensive.

If you're sticking with a lead/acid battery, or anything other than a dry cell, that Moroso box is a VERY good idea, to ensure your personal health. A circuit breaker is also a good idea, to prevent the battery from burning if your main relocation cable grounds to the body anywhere. A power distribution box is good for under the hood, to get rid of the stock fusible links and neaten up the wiring harness considerably.

 

[Defiant]

Off topic, WOW that batter relocation kit is expensive!

And you just don't get that many flapjacks out of a batch, either.

 

[gsxeclipse97]

Well how much does the FMIC weigh in general? I'm trying to find a way to balance the car more than what it is. So far ive gotten carbon fiber hood relocate battery to rear. I have a 10" sub and box also in the trunk and the spare tire but I' dont want to take that out cause i live in houston and they are always doing constrution on I-10. Also when i do the battery relocation would it be better for me to have a stero shop like best buy install so they can hide all the wires as well? Auto cross is the goal im going for in my car not just top end drag power so i need to find other ways to im prove handling out side the basic spring struts and what not

 

[nightspeed87]

This is a bit off topic and may be a basic question but felt I had to drop it somewhere but out of curiousity how does the torque split in the dsm awd system work when your doing donuts or trying to drift it? Like how does it deal with those situations?
( I know its not good to try to drift or do donuts on dry ground i believe. )

 

[Talesin]

Uh... it doesn't. 50/50 locked, full-time. Sometimes you can weight transfer a drift, but all four are going, and all of them are getting the same power. Don't think I've ever seen an AWD (much less an AWD DSM) doing proper donuts. Trying to imagine how that'd work, as you'd generally just understeer out of it.

 

[pnishr]

Would be nice to get a 35/65 (or 30/70) split to take some of the accelleration traction load off the front tires, but it doesn't seem to be in the cards for our cars. :b

Actually there IS a 35/65 center diff for our cars. There's a link to one of the threads about it. And a link to ONE of the places that carries it. It's Cusco. I've been interested in this myself.


http://www.dsmtuners.com/forums/showthread.php?t=182272&highlight=35/65+LSD+cusco

http://www.napsusa.com/cgi-bin/napsusa/510-020-A.html

 

[Rob10_99]

back on topic,

I used to have several dsm's all AWD,
now I have an 03 350z, the thing is with the Z, it is WAY stiffer chassis, and weight distro islike 47/53 or something, that engine is tucked in there,
as for handling, I have non stock tires, 20" wheels with 285's and 245s,
for high speed cornering I can whip a dsm no problem, seriously,
I had sways and full suspension setulp on my 91, and it always wanted to kick the rear out or understeer. but theres always more throttle with a dsm.

it was weird at first going from a hard hitting turbo to a NA v6, but in the end I wouldsayits more reliable, but eats gas with a leadfoot,
any comments?
btw I recently got a gxsr1k and dumped it so im drugged up1

 

[nightspeed87]

Uh... it doesn't. 50/50 locked, full-time. Sometimes you can weight transfer a drift, but all four are going, and all of them are getting the same power. Don't think I've ever seen an AWD (much less an AWD DSM) doing proper donuts. Trying to imagine how that'd work, as you'd generally just understeer out of it.

Can somebody explain to me why its not good to drift or do donuts in a dsm then ( Perhaps when the grounds dry, I dont know if that applies to not doing them on wet ground.)
Not that Im looking to do this, but just in case I get carried away one day in the rain since it rains a lot in Fl, Id like to know... Its something I never thought about having an ill effect from before but would like to know just in case.. Thanks.

back on topic,

I used to have several dsm's all AWD,
now I have an 03 350z, the thing is with the Z, it is WAY stiffer chassis, and weight distro islike 47/53 or something, that engine is tucked in there,
as for handling, I have non stock tires, 20" wheels with 285's and 245s,
for high speed cornering I can whip a dsm no problem, seriously,
I had sways and full suspension setulp on my 91, and it always wanted to kick the rear out or understeer. but theres always more throttle with a dsm.

it was weird at first going from a hard hitting turbo to a NA v6, but in the end I wouldsayits more reliable, but eats gas with a leadfoot,
any comments?
btw I recently got a gxsr1k and dumped it so im drugged up1

I have a friend with a 350z and his car handles precisely ( far from stock )
And it feels like it can definitly out manuever both my dsms.
Its a 300 plus whp all motor soon to be turboed. Honestly though I feel there is more
entry and exit vehicle control when the motor isnt turbo charged, because the power band will tend to be more linear than in a boost applied vehicle where it can tend to have a dip, or a spike in the power band, but then again with proper control and throttle input it can also be an advantage. ( Not in all setups though of course. )

 

[Zenja]

Uh... it doesn't. 50/50 locked, full-time. Sometimes you can weight transfer a drift, but all four are going, and all of them are getting the same power. Don't think I've ever seen an AWD (much less an AWD DSM) doing proper donuts. Trying to imagine how that'd work, as you'd generally just understeer out of it.

Figures, considering you're in California I've done many proper donuts in my AWD in the snow here. It works just fine.

Also, even though the balance is normally 50/50, when some wheels start to slip, the amount of power being transferred to those wheels changes.