Mainly to make up the weight difference for HHR, and also less stress on the trans due to the extra weight.

On a small turbo like the K04, shorter gear really doesn't hurt.

 

What about the HHR though, it got the 4.05.

 

Um, my post explains that... What don't you understand?

It was directed towards the HHR.

 

I was responding to Wert and your post wasn't there yet. That makes sense though.

 

Troof 300 lbs is a lot of weight.10% of overall mass pretty much.

lol@ wes resurrecting the " u need tall gears to let the turbo spool up" debate.

short-= qwik. whatever you got.
short = crummy fuel mileage whatever you got
short= longer trans life whatever power you got
long = (-) the above

 

Has anyone mentioned straight cut gears yet?

I know GM owns their helical gear design, but why not go with a more common helical cut? If the ring and pinion gears are cut the same way (as in not mixing a GM gear with a common cut gear), there shouldn't be an issue, right?

 

Except cost would be huge.

If you're gonna live at or below 500whp, the 4.45 is fine for you. If you want 600, 700. Well I'd go F40. Although I am convinced the gearing ratio on the 4.45 is the shiznit.

 

I had kept seeing so many ZFR blow up their transmission cause of torque. What I would do is upgrade clutch and put in transmission cooler in. That's just Me, cause I would want to cool that bitch down since it will create stress and heat in transmission. If there's a way to put in transmission cooler ? I don't see why not.

 

Cooling the trans isn't the issue, its just stress on gears

 

Ok, I was thinking if stress on gears with hotter trans fluid. That may cause trans gears runs even more hotter cause of hitting the gas with all of those stress. Right ? If You run trans cooler by putting extra trans fluid in then You hitting gas and Yeah that may stress trans but when You finish racing or whatever. Then that give transmission to cool down with all of that stress ?

 

I don't think it's the ZFR causing these issues so much so as it's the aftermarket clutches people are running....

A stock/GMPP clutch will slip before the trans says "I'm out!". An aftermarket clutch will not and therefor, the next weakest link is the trans.

Either way, if it were me, I'd toss in an HHR/LSJ 4.05 and stick with a full faced disc clutch.

 

Ok, I got it.

 

Good point

 

Surprised at most people who got a zfr didn't change out the geatlrs before they break.I know this is what I am doing. Hell of a lot cheaper that's for sure. Anybody cryodip the gears?

 

I think fmsr does. I think most people just want the all out power before try think of breaking anything lol

 

Tell me about it. It was my mistake. Somehow I thought that the reason ppl were blowing trannies was the same reason people are frying clutches, i.e. stupidity...

To anyone that is considering the zfr turbo I would say get the tranny before it breaks. It will save you at least $1,000 plus the aggravation of having the car be down for weeks or longer

 

Every time I look at your signature I just see the 359 WHP and 4148 TQ and know why the transmission died. You have to be making more than that now too.

 

Should be quite a bit more
I actually never had issues with those numbers on the stock turbo, and I did many "***** to the wall" track days. Remember though that I'm at 5,400 feet so the components never actually get to see those torque numbers due to the thinner air...

 

It would be good to do if there were actual gears to swap into the trans, but there isn't anymore around. Whole reason why they are scarce. Should just swap a lsj trans to be on the cheaper and s bit safer side.

Sent from my Samsung Galaxy S4 using CobaltSS

 

Like this?
Not sure its worth it, but we know how to make them and install them




also you would cryo the case and RIM finish the gears. We did one for mongorat, but I am not sure if it makes it any more durable. Mongo rat loves it. costs a lot of money to do. complete strip down to the last nut and bolt.
dont forget the market is limited for cost/benefit/performance

 

Do these rattle in neutral before they grenade? If so...

 

rare for an sc to grenade the trans.
clutch rattle on idle for you would not be a surprise to me based on what that imposter tech was doing to your car lol

 

You should hear my car going down the road when it's 20 degrees F outside. Sounds awful

 

They wanted me to leave it and get into another rental when I called about the squeaking in neutral lol. I was like no thanks, you're just going to ruin it even further lol

 

Or they spent all their money making the car go fast and a new trans isn't in the budget until it pops.