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MrJoshua
MrJoshua UltimaDork
4/3/22 9:25 a.m.
te72 said:

........ Also reminds me of what could have been, had Toyota paired the 2ZZ with the AWD option on the old Matrix...

Noooo! The 2ZZ is too peaky for AWD in that porky chassis. Now if you gave it a shorter final drive, or boost,  AWD would be a riot.

(Also need to fix the dumb 1-2 gear spacing and/or lift threshold)

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
4/3/22 9:40 a.m.

In reply to MrJoshua :

Indeed, the benefit of a revvy engine is that it is easier to pedal in a traction limited vehicle.  Turbos and all wheel drive go together like biscuits and gravy.  You can exploit the mid range pull and the nonlinearity of the power delivery does not need to be minded for traction.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
4/3/22 10:52 a.m.

That was the justification behind the cammed 5.3 in my original Targa Miata build. Supposedly easier to drive because it had to be revved to perform. That turned out to be horsepucky. No problem at all managing traction with the torquey 6.2 and massively more speed. 

Predictable power delivery is easy to manage. It's unpredictable delivery that you've gotta watch for, and non linear is not unpredictable. 

te72
te72 Reader
4/3/22 3:06 p.m.

In reply to MrJoshua :

Those cars definitely needed a shorter final drive, or perhaps a really tall 6th gear and close 1-5 to really take advantage of that engine's fun characteristics. Ever try driving an automatic 2ZZ? Yuck.

te72
te72 Reader
4/3/22 3:08 p.m.

In reply to Pete. (l33t FS) :

That's kinda what I'm looking forward to. The Supras can put the power down, but you are somewhat surface limited, and around here the surfaces aren't usually good. You learn to drive around it, and learn to handle a car with the rear wheels always spinning, but I've never had an awd. Good friend of mine says it's practically cheating how easy it is to drive in the snow and ice.

te72
te72 Reader
4/3/22 3:12 p.m.

In reply to Keith Tanner :

Generally speaking, that linearity is why I prefer naturally aspirated engines, but at 6500' elevation, it has to be a big one, or it's gonna be beyond slow.

 

That's also why I swapped out my old mid frame turbo for a Garrett G25-660. Much more fun to drive, and it's not like it lacks theatrics when you have 80% of your peak torque, all the time. Hmm... I wonder if that G16 on the Corolla would be amenable to a turbo swap... I have a spare G25, hmm.

NickD
NickD MegaDork
4/3/22 3:14 p.m.

Those cylinder walls are stout. Should be stable with the boost turned up

Berck
Berck Reader
4/3/22 4:36 p.m.

In reply to NickD :

According to one of the videos in the thread, the head gasket starts leaking around 450hp...  Once you figure that out, it does look like there's a potential for more power, if that's your thing.  When I build a computer, I buy all the highly-reviewed overclocking parts, but then I don't actually overclock anything so that I know I've got something that will be reliable with margin for error.  I want the same thing out of my cars.

In reply to te72 :

The turbo is integrated into the manifold. Turbo upgrades are doable, but it's not as simple as a turbo swap, fueling adjustments and remapping the ECU. 

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
4/3/22 4:44 p.m.

In reply to Berck :

That is why I was happy to hear that the engine in the S60R was basically a 600hp engine detuned to 300.

Some people can break a crowbar in a sandbox, though.

fidelity101
fidelity101 UberDork
4/3/22 6:06 p.m.
Berck said:

In reply to Keith Tanner :

The Focus RS is similar, but a little more fancy using a computer controlled dual clutch pack in the rear and a fixed power takeoff unit instead of a center diff. Modern clutch materials are impressive, but of course these are wet clutches which makes dealing with constant slip easier.  I suspect that worry about those clutch materials at high temps is why the Focus RS only lets me drive about 20 minutes on the track before it decides the rear drive unit is too hot, opens the clutches and turns it into a 350hp FWD machine which is funny, but not particularly fun.

this is why I hate the focus RS. huge let down - the Toyota should triumph gloriously in this area I hope. 

Berck
Berck Reader
4/3/22 6:20 p.m.

In reply to fidelity101 :

I mean, it depends on what your desires/expectations are.  The RS is great for what I bought for--fun street car that can handle snow.  I didn't find it particularly fun on the track, and it's so clever at correcting for bad driving it actively got in the way of my wife learning how to drive on the track.  I'd much rather drive the Miata on the track any day.

But it was absolutely advertised for track use, (though only 30 minute sessions!), and its performance in that area was disappointing.  In addition to the RDU disconnect after 20 minutes, the oil temperature was nearing the 300F redline and the brakes went squishy on the factory fluid.  On a fairly cool day in Colorado.  Track use (especially at altitude) is just brutal, and Ford should have been more up front about the limitations.  I don't know if the Corolla will do any better in terms of track longevity, but I doubt it'll do any worse.

Mr. Lee
Mr. Lee GRM+ Memberand PowerDork
4/3/22 9:33 p.m.

Our '21 XSE hatch came in at 29k. That's fully loaded. Actually got a letter from the dealership offering purchase price for trade in the other day so while I was at the dealership getting it serviced I looked around the lot. They had less than 10 new units on the lot. 1 Camry an Avalon a fully loaded tundra and a handful of Tacoma's and highlanders.  They asked if there was anything that would possibly interest us to trade in the rolla. RAV4 hybrid is the only thing SWMBO would consider so that was the answer.  They can't find one. 
 

So unless they sort this crap out. Good luck finding one. The core edition in 2wd would tickle me to death. But awd never hurts. The other issue We've got 0.9% financing on our 21. That was the reason for going ahead with with the XSE trim. Not sure it will happen again anytime soon. 
 

To answer the first question. 35-40k though if they start the core edition at 32 I'll be in line. 

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
4/3/22 9:52 p.m.
te72 said:

In reply to Pete. (l33t FS) :

That's kinda what I'm looking forward to. The Supras can put the power down, but you are somewhat surface limited, and around here the surfaces aren't usually good. You learn to drive around it, and learn to handle a car with the rear wheels always spinning, but I've never had an awd. Good friend of mine says it's practically cheating how easy it is to drive in the snow and ice.

I had two all wheel drive cars before the Volvo, but they had dumb diffs and no power.  My HSQ moment was when I was at a light and punched it while making a right turn.  No sturm, no drang, just 300ft-lb moving the car, changing direction and accelerating in a way that felt like cheating.

Then I did the same thing in the rain.  That time I KNEW I was cheating smiley

turtl631
turtl631 HalfDork
4/3/22 10:44 p.m.

After daily driving s2000, c6 z06, and f80 M3 (in succession)  year round with snows here in Wisconsin, my current TT RS feels like total cheat mode with the used snows from the M3 on it.  Similar power: weight, but just puts it down in conditions the M3 was lighting them up.  I'm cheering for the GR Corolla... Was tempted by Golf R, STi, and Veloster N, but the ridiculous Audi I5 DAZA motor won me over for what will probably be my last pure ICE daily.  

AnthonyGS (Forum Supporter)
AnthonyGS (Forum Supporter) GRM+ Memberand UltraDork
4/3/22 11:14 p.m.

In reply to turtl631 :

Audi's are just totally amazing cars in crap weather.  In my S4 of old, I tormented every performance car on the planet whenever the roads were slick.  It was almost comically fun.  You can drive Audi's in plain silly fashion on crap roads.  The real danger is that an Audi is capable of mad acceleration in bad conditions, but stopping is about as terrible as any other car on similar tires. 

engiekev
engiekev HalfDork
4/4/22 8:38 a.m.
fidelity101 said:
Berck said:

In reply to Keith Tanner :

The Focus RS is similar, but a little more fancy using a computer controlled dual clutch pack in the rear and a fixed power takeoff unit instead of a center diff. Modern clutch materials are impressive, but of course these are wet clutches which makes dealing with constant slip easier.  I suspect that worry about those clutch materials at high temps is why the Focus RS only lets me drive about 20 minutes on the track before it decides the rear drive unit is too hot, opens the clutches and turns it into a 350hp FWD machine which is funny, but not particularly fun.

this is why I hate the focus RS. huge let down - the Toyota should triumph gloriously in this area I hope. 

The "GR AWD" system uses the same clutch coupling system as the Focus RS, but one clutch before the rear diff instead of a clutch after the diff at each axle (which allowed the RS to torque vector).   So in a way it is less complex and less capable than a "dual clutch" AWD system. Notably, both systems overdrive/overspeed the rear differential.

In that sense it is most definitely possible to overheat the clutch packs, just like the RS, and it also would default to a FWD drivetrain with AWD limp mode.  Most modern AWD Systems with a clutch pack use a temperature model for the clutches (sensor for the sump oil temp), and puts the system into limp or protection mode at a certain temp.  Even RWD based AWD systems do this.  How often it overheats and in what conditions depends on how the system was designed, the temp model is calibrated, and driving conditions.  More wheelspeed differential will drive higher clutch temps, so low-mu gravel/snow will increase clutch temps in general, this might not bode well for the GR AWD system in rally use.  Team O'Neil ran into these issues with trying to campaign the RS in stage rally.

From Yaris AWD System explanation:

"The system’s ECU controls the drive torque distribution to suit the driving situation, according to data gathered on vehicle performance such as speed, acceleration, braking and steering. Electronic control of the multi-plate clutch uses information from the wheel speed and G sensors and the clutch’s temperature sensor." - Not common to have a clutch temp sensor built into the clutche coupling themselves, so this may be marketing jargon and there might be a temperature model with a oil temp sensor.

https://www.autoevolution.com/news/toyota-gr-yaris-awd-system-can-overheat-this-is-what-happens-when-it-does-166717.html

The Evo X had a similar system as the RS (and Honda's SHAWD) with two clutch packs at the rear diff, but there aren't many reports from overheating the rear diff on those.

Compared to the RS: as mentioned it is a FWD trans with PTU, as opposed to an AWD transmission with center differential.  Rear diff is also oversped/overdriven.  The 

Yaris GR AWD has a single clutch pack before the rear differential, which is oversped from the front (so the clutch is constantly slipping with AWD engaged, except in the 30/70 split where the clutch packs are locked).

https://www.gr-yaris.co.uk/forum/threads/gr-yaris-awd-system-explained.916/

https://www.youtube.com/watch?v=uetY5CSckPg

NickD
NickD MegaDork
4/4/22 9:41 a.m.

Pretty interesting that the first motorsport debut of the Corolla GR was in Formula Drift this weekend, with Ryan Tuerck driving the Papadakis Racing Corolla GR, and it qualified first and won the event. The car actually began life as a Scion iM (remember those), then was reskinned as a Corolla iM, then as the Corolla Hatchback, and then this year was updated to a Corolla GR. It uses all the stock Corolla suspension pickup points and strut tower and firewall, but uses a 1000hp 2AR turned north-south feeding a sequential gearbox and then a MkIV Supra differential housing with racing guts (it also uses MkIV Supra rear wheel bearing/hub assemblies).

They had to have the car present for Media Day on Wednesday and practice on Thursday, and the Corolla GR hadn't been unveiled, so they had to camouflage the front and rear of the car, and then were able to unveil it on Friday for qualifying.

Toyota had a pretty solid presence at Formula D this weekend. There were three GR Supras (2 with the B58 engine and 1 with a 2JZ), the GR Corolla, and two of the new GR86s (one with an LS engine and one with the GR Supra B58 engine). 

z31maniac
z31maniac MegaDork
4/4/22 10:12 a.m.
fidelity101 said:
Berck said:

In reply to Keith Tanner :

The Focus RS is similar, but a little more fancy using a computer controlled dual clutch pack in the rear and a fixed power takeoff unit instead of a center diff. Modern clutch materials are impressive, but of course these are wet clutches which makes dealing with constant slip easier.  I suspect that worry about those clutch materials at high temps is why the Focus RS only lets me drive about 20 minutes on the track before it decides the rear drive unit is too hot, opens the clutches and turns it into a 350hp FWD machine which is funny, but not particularly fun.

this is why I hate the focus RS. huge let down - the Toyota should triumph gloriously in this area I hope. 

They sell diff coolers for the RS. 

They have to do the same thing for Mustang GTs because the diff overheats in track use for fast drivers and pukes fluid everywhere. 

te72
te72 Reader
4/4/22 10:12 a.m.
Captdownshift (Forum Supporter) said:

In reply to te72 :

The turbo is integrated into the manifold. Turbo upgrades are doable, but it's not as simple as a turbo swap, fueling adjustments and remapping the ECU. 

Long as the manifold isn't integrated into the head, that would be fine. From what I've seen, this isn't a concern here. =)

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
4/4/22 10:19 a.m.

In reply to z31maniac :

I thought the issue with the FoRS diff was that the temperature was calculated, not measured.  You can cool it all you like but the module will assume that it is overheating.

engiekev
engiekev HalfDork
4/4/22 12:27 p.m.
Pete. (l33t FS) said:

In reply to z31maniac :

I thought the issue with the FoRS diff was that the temperature was calculated, not measured.  You can cool it all you like but the module will assume that it is overheating.

That's exactly right, the clutch temperature and rear diff temp is modeled.  The power take off from the trans (PTU) temp has an oil sensor, but the rear diff (RDU) actual clutch temp is a model based off that and other inputs. So even if one were to improve the physical cooling, the model would not know and the limp mode would still occur (unless you have some ability to flash a diff controller, unlikely, or calibrate an aftermarket diff controller like Syvecs).  Reducing the oil temps might help, but it won't solve the root cause if the RDU is overheating.

EDIT: it sounds like both the PTU and RDU are overheating in the RS. PTU overheats, so the RDU model based on PTU temp goes into limp mode.  Some are experimenting with PTU cooling to avoid this (effectively cooling the temp input into the RDU model), and RDU coolers as well.

https://www.focusrsforum.com/threads/diffs-hot-take-it-easy-mishimotos-focus-rs-rear-diff-cooler-r-d.458/

Now the question would be how does this work in the GR AWD system?  There's likely a clutch temp model but what is it based on, and is there any fluid/hardware that can be cooled to reduce AWD shutdowns?

engiekev
engiekev HalfDork
4/4/22 1:09 p.m.

Our dreams of Corolla GR's taking over the streets is not aligned with toyota's goals.  This is pretty low, for reference the 2003 Evo8 was 7100 units, 2006 Evo 9 ended with roughly 8200 units.

"Toyota's maintaining flexibility for that reason, but Tripp says the company is predicting that a full year of sales will end up around 8000 units. Expect 2023 to fall shy of that number, with the production ramp and limited early availability limiting total sales to around 6000 cars."

https://www.roadandtrack.com/news/a39612033/gr-corolla-production-numbers/

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
4/4/22 1:09 p.m.

In reply to engiekev :

HPT claims ability to tune the FoRS's RDU.  The old tune repository is gone and I have not checked lately to see if anyone has uploaded a stock tune so I can poke around in it.

thashane
thashane GRM+ Memberand Reader
4/7/22 11:19 p.m.

4/06 Toyota Video is talking big talk. I am the excited - still

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