How hard is it safe to launch w/ a stock GVR4 trans & tcase? If the trans and tcase are getting freshened up, are there any (cheap) upgrades that really improve launch strength?
-TJ
-TJ
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Brianawd
Well-known member
Quote:
How hard is it safe to launch w/ a stock GVR4 trans & tcase? If the trans and tcase are getting freshened up, are there any (cheap) upgrades that really improve launch strength?
I launched the sh*t out of my car with a stock trans. 6k studder box on the e316g. Did it for 2 years. I then took out the weak gay galant vr4 1st gear. If you are rebuilding your trans. You can put in a evo3 1st gear or a dsm 1st gear. Both are stronger. The evo is the best. You can also so a double cone 2nd.
Here is what is in my trans.
dsm 1st gear
double cone 2nd
Big 3/4.
Now when I say big 3/4 I mean the syncro's. Earlier trans have stonger gears but the syncro's and junk. So if you move to a later 3/4 gear you get the better syncro's but with weaker gears. If you want to stay with the earlier gears then you have to double syncro them if you want them to shift right. Right now I am at the point with my power leave that I need to step up to the evo 3 gear set.
How hard is it safe to launch w/ a stock GVR4 trans & tcase? If the trans and tcase are getting freshened up, are there any (cheap) upgrades that really improve launch strength?
I launched the sh*t out of my car with a stock trans. 6k studder box on the e316g. Did it for 2 years. I then took out the weak gay galant vr4 1st gear. If you are rebuilding your trans. You can put in a evo3 1st gear or a dsm 1st gear. Both are stronger. The evo is the best. You can also so a double cone 2nd.
Here is what is in my trans.
dsm 1st gear
double cone 2nd
Big 3/4.
Now when I say big 3/4 I mean the syncro's. Earlier trans have stonger gears but the syncro's and junk. So if you move to a later 3/4 gear you get the better syncro's but with weaker gears. If you want to stay with the earlier gears then you have to double syncro them if you want them to shift right. Right now I am at the point with my power leave that I need to step up to the evo 3 gear set.
slobra
Well-known member
Good info, I was wondering the same thing. I just bought a chip with a 6k stutterbox. I'll probably upgrade the trans before I start using the stutterbox for safe measure.
atc250r
Staff member
On the flip side, I made about a dozen passes down the strip going high 12's on my small 16G when I first built my car and it spit a piece of a center diff spider gear through the case. Anytime you go and beat the crap out of your car like that you have to be prepared for the possibility of consequences like that.
John
John
Brianawd
Well-known member
Oh also forgot to add that I have a welded CD
atc250r
Staff member
doh! Withholding vital info, eh? /ubbthreads/images/graemlins/rofl.gif
John
John
slobra
Well-known member
Quoting Brianawd:
Oh also forgot to add that I have a welded CD
Welding the center diff locks everything 50/50 correct? Is the only downside the tires skipping or skidding a little while you are trying to park?
Oh also forgot to add that I have a welded CD
Welding the center diff locks everything 50/50 correct? Is the only downside the tires skipping or skidding a little while you are trying to park?
Brianawd
Well-known member
Quote:
Welding the center diff locks everything 50/50 correct? Is the only downside the tires skipping or skidding a little while you are trying to park?
Correct diff is locked 50/50. That is one of the down sides. It also makes the car harder to turn when in parking lots. You will also brake more axles and u joint's. I would rather brake those than the CD. When the CD brakes it can sent chunks out the case of the trans.
One of the things my friends and I have learned is that in the HP cars with a open CD the car will porpus front to back because the car will hook in the back then the front making the car buck. By welding the CD it has made the come out of the hole much better.
Here first vid shows open CD and the secend shows a weld CD
click
click
Welding the center diff locks everything 50/50 correct? Is the only downside the tires skipping or skidding a little while you are trying to park?
Correct diff is locked 50/50. That is one of the down sides. It also makes the car harder to turn when in parking lots. You will also brake more axles and u joint's. I would rather brake those than the CD. When the CD brakes it can sent chunks out the case of the trans.
One of the things my friends and I have learned is that in the HP cars with a open CD the car will porpus front to back because the car will hook in the back then the front making the car buck. By welding the CD it has made the come out of the hole much better.
Here first vid shows open CD and the secend shows a weld CD
click
click
tsiboy
Well-known member
^^^ wow ive never seen it in slow motion like that. that was great!
bazeng
Well-known member
I'm not actually sure if it is 50/50
I have had my car on the dyno and here is the power difference between front to rear with a TRE spool.
E39A is my car making 330kw's at the wheels
Proevo has a viscous centre making about 310kw's at the wheels.
The dyno was set on locked 4wd..
I'm thinking that our cars when locked are more rear biased.... as the dyno displays
I have had my car on the dyno and here is the power difference between front to rear with a TRE spool.
E39A is my car making 330kw's at the wheels
Proevo has a viscous centre making about 310kw's at the wheels.
The dyno was set on locked 4wd..
I'm thinking that our cars when locked are more rear biased.... as the dyno displays
turbowop
Well-known member
It is 50/50 with a welded diff and with the stock viscous coupling. If it weren't 50/50, with a welded diff, you wouldn't be able to drive the car on pavement as it would tear apart the drivetrain from the front/rear wheels spinning at different speeds.
slobra
Well-known member
Im thinking about getting my center diff welded. I have an E316G, 560cc injectors, 2gmaf, ETS FMIC, 3" TB Exhaust all bought and ready to go on the car. I was planning on running the 14B and all supporting mods until I'm more familiar with the car before slapping on the 16G. Would you guys recommend me waiting until I have the bigger turbo on to weld the center diff? I'm guessing it wouldn't matter but this is my first turbo awd car I've ever had so I'm researching EVERYTHING. Thanks for the info guys.
Quoting turbowop:
It is 50/50 with a welded diff and with the stock viscous coupling. If it weren't 50/50, with a welded diff, you wouldn't be able to drive the car on pavement as it would tear apart the drivetrain from the front/rear wheels spinning at different speeds.
+1, Bazeng they are referring to the front axle being 50/50 side to side, not front/back.
This is why the tyres "skid" horribly in parking lots.
It is 50/50 with a welded diff and with the stock viscous coupling. If it weren't 50/50, with a welded diff, you wouldn't be able to drive the car on pavement as it would tear apart the drivetrain from the front/rear wheels spinning at different speeds.
+1, Bazeng they are referring to the front axle being 50/50 side to side, not front/back.
This is why the tyres "skid" horribly in parking lots.
Last edited:
bazeng
Well-known member
It is 50/50 with a welded diff and with the stock viscous coupling.
I'm running a TRE spool without a viscous coupling.
If you look at the dyno graph, it shows that the rear makes quite a bit more power than the front wheels.
I'm not sure why, I would have thought that if it were 50/50, I would have exactly the same power front to rear.
Anybody have access to a dyno who can dig up a old run with a locked centre, and set the graph to show front and rear power?
I'm running a TRE spool without a viscous coupling.
If you look at the dyno graph, it shows that the rear makes quite a bit more power than the front wheels.
I'm not sure why, I would have thought that if it were 50/50, I would have exactly the same power front to rear.
Anybody have access to a dyno who can dig up a old run with a locked centre, and set the graph to show front and rear power?
Lonewolf64
Well-known member
Quoting slobra:
Im thinking about getting my center diff welded. I have an E316G, 560cc injectors, 2gmaf, ETS FMIC, 3" TB Exhaust all bought and ready to go on the car. I was planning on running the 14B and all supporting mods until I'm more familiar with the car before slapping on the 16G. Would you guys recommend me waiting until I have the bigger turbo on to weld the center diff? I'm guessing it wouldn't matter but this is my first turbo awd car I've ever had so I'm researching EVERYTHING. Thanks for the info guys.
I wouldn't weld the CD unless you are building a drag car. Honestly, for a 16g, you will probably not break the diff unless you launch multiple times on a drag strip. If you are launching on the street you'll most likely never have a problem with that (I'm not saying something else won't break). At most, I would upgrade to a spider differential because that doesn't hurt day to day driveability and handling.
Im thinking about getting my center diff welded. I have an E316G, 560cc injectors, 2gmaf, ETS FMIC, 3" TB Exhaust all bought and ready to go on the car. I was planning on running the 14B and all supporting mods until I'm more familiar with the car before slapping on the 16G. Would you guys recommend me waiting until I have the bigger turbo on to weld the center diff? I'm guessing it wouldn't matter but this is my first turbo awd car I've ever had so I'm researching EVERYTHING. Thanks for the info guys.
I wouldn't weld the CD unless you are building a drag car. Honestly, for a 16g, you will probably not break the diff unless you launch multiple times on a drag strip. If you are launching on the street you'll most likely never have a problem with that (I'm not saying something else won't break). At most, I would upgrade to a spider differential because that doesn't hurt day to day driveability and handling.
Brianawd
Well-known member
If you have the money do a 4spider. If you don't, weld the diff. I don't car if your launching your car on the street or at the track. If you get any little bit of wheel hop and do not get off the gas fast enough, say good buy to you CD.
atc250r
Staff member
I agree with Brian. If you can't afford a 4 spider then at least have it welded. Like I said in my previous post, I spit a spider gear out after about a dozen launches at the track and none on the street. I never wheel hopped or anything, the car left very nicely but it didn't matter. When the CD pukes a spider and makes a hole in your case you'll wish all you had was some minor binding when parking.
John
John
Is the GVR4 1st gear really that much weaker?
If my trans is getting built locally is there somewhere I can order a 4-spider?
I hear such mixed things about going with a center spool/welded diff. The car will be 99% street driven getting the occasional use for a rainy AutoX.
-TJ
If my trans is getting built locally is there somewhere I can order a 4-spider?
I hear such mixed things about going with a center spool/welded diff. The car will be 99% street driven getting the occasional use for a rainy AutoX.
-TJ
Lonewolf64
Well-known member
A welded diff is pretty terrible for autox where a lot of the maneuvering is tight and low speed. It's your choice though.
atc250r
Staff member
If you're going to AutoX it then you'll want to either buck up for a 4 spider or keep the stock CD but DO NOT launch it.
John
John
