Turbocharged vs supercharged

[Irace86.2.0]

Originally Posted by Ultramaroon

Basically, the compressor is geared low for the displacement so it becomes the limiting factor in the system. It spools later in the game but when it does, it's super responsive and is literally unable to overspeed the compressor. The combination is tuned for play above the vvt crossover speed.

So how are people seeing higher boost levels?

[Grady]

Originally Posted by Irace86.2.0

So you plugged the port on the wastegate or left it to atmosphere, and you plugged the bung on the turbo, so you weren't bleeding boost to atmosphere, and you took the car to redline to see what the turbo would do, and 10 psi was the max? All you had was an AVO kit on the car?

Uhhh, really?

Yep, Was tuning the car with Zach(Mike you are so lucky to have him in house now!!!!) and could not get the boost to quit tapering off at red line. Zach was sure the stock exhaust was the limiting factor, I wanted to verify before spending a ton of money on exhaust.

[Irace86.2.0]

Originally Posted by Grady

Yep, Was tuning the car with Zach(Mike you are so lucky to have him in house now!!!!) and could not get the boost to quit tapering off at red line. Zach was sure the stock exhaust was the limiting factor, I wanted to verify before spending a ton of money on exhaust.

Maybe you could answer the last question too, which was how are others extracting more boost on this platform and others with the same turbo if the turbo is maxed at 10 psi?

More power mods have a feed forward effect on the turbo, so maybe if someone didn't have anything else going on for power or E85, and they could keep IAT down, but even then, we have examples of people doing 14 psi on pump gas.

https://www.ft86club.com/forums/showthread.php?t=53124

[Ultramaroon]

Originally Posted by Irace86.2.0

So how are people seeing higher boost levels?

I guess let's wait for his reply. I understood that he mated an oversized turbine to a small compressor.

[86TOYO2k17]

OP is going to be so confused if he makes it this far.

[Irace86.2.0]

Originally Posted by 86TOYO2k17

OP is going to be so confused if he makes it this far.

He was asking specifically for his automatic. We don't know if he has access to E85 or not. We don't know what his power goals are. It really doesn't make much difference if they are low.

Typically the autos aren't holding as much power as the manuals, so maybe a supercharger for reliability and less low end torque, but the autos have longer gears, so a turbo would be nice.

[Grady]

Originally Posted by Irace86.2.0

Maybe you could answer the last question too, which was how are others extracting more boost on this platform and others with the same turbo if the turbo is maxed at 10 psi?

More power mods have a feed forward effect on the turbo, so maybe if someone didn't have anything else going on for power or E85, and they could keep IAT down, but even then, we have examples of people doing 14 psi on pump gas.

https://www.ft86club.com/forums/showthread.php?t=53124

That post if from 2013, all those engines have blown up!

[Irace86.2.0]

Originally Posted by Grady

That post if from 2013, all those engines have blown up!

Ok. Thanks for the non-sequitur.

H-O-W D-I-D T-H-E-Y G-E-T M-O-R-E B-O-O-S-T?

[86TOYO2k17]

Originally Posted by Irace86.2.0

He was asking specifically for his automatic. We don't know if he has access to E85 or not. We don't know what his power goals are. It really doesn't make much difference if they are low.

Typically the autos aren't holding as much power as the manuals, so maybe a supercharger for reliability and less low end torque, but the autos have longer gears, so a turbo would be nice.

This thread has gone down a random rabbit hole veering far away from original topic was my point.

and typically the autos are holding much more power than manuals. both in real world testing as well as in manufacturer rating. Also several mods to beef up the auto, but the auto can already hold more power than the FA20 can reliably hold.

[Irace86.2.0]

Originally Posted by Grady

That post if from 2013, all those engines have blown up!

I have another example. 06' WRX T518Z 18-21psi 2.0L flat 4 engine.

8cm^2 vs 10cm^2

10cm should be larger, so more lag, but less top end choke.

https://forums.nasioc.com/forums/sho....php?t=1836622

[Irace86.2.0]

Originally Posted by 86TOYO2k17

This thread has gone down a random rabbit hole veering far away from original topic was my point.

and typically the autos are holding much more power than manuals. both in real world testing as well as in manufacturer rating. Also several mods to beef up the auto, but the auto can already hold more power than the FA20 can reliably hold.

I don't know. I always thought the autos were weaker than the manuals, but it seems I was mistaken. I just read that the torque rating of the A960E is like 260tq and the AZ6 is like 165tq or something like that.

[86TOYO2k17]

Originally Posted by Irace86.2.0

I don't know. I always thought the autos were weaker than the manuals, but it seems I was mistaken. I just read that the torque rating of the A960E is like 260tq and the AZ6 is like 165tq or something like that.

The autos are pretty beefy.

A960E is rated at 220ft lbs. SSP valve body should be good for 240ft lbs, ssp clutch pack 400ft lbs. oil cooler helps a lot too not for overall rating but overall reliability.

AZ6 is rated at 180 ft lbs. but with a clutch upgrade it seems to be between about 200-220ft lbs.

Needless to say us auto boys aren’t too concerned with the trans. Just the rods which seems to have decent reliability at about 220-240ft lbs.

And the longer stretched gears like you mentioned would pair well with a turbo.

[Irace86.2.0]

Originally Posted by 86TOYO2k17

The autos are pretty beefy.

A960E is rated at 220ft lbs. SSP valve body should be good for 240ft lbs, ssp clutch pack 400ft lbs. oil cooler helps a lot too not for overall rating but overall reliability.

AZ6 is rated at 180 ft lbs. but with a clutch upgrade it seems to be between about 200-220ft lbs.

Needless to say us auto boys aren’t too concerned with the trans. Just the rods which seems to have decent reliability at about 220-240ft lbs.

And the longer stretched gears like you mentioned would pair well with a turbo.

I believe the AZ6 transmission is rated at 163 tq. The clutch might be more like 180. I'm at a bar of boost on E85 with an Exedy stage 1. No issues so far. I mean, I have 5th gear grind from the previous owner. I think the transmission can obviously hold more, but I don't know over the life of the car. We will see.

Johan who sold me his Harrop kit, said he was switching to a turbo because he blew his auto trans. Autos with a torque converter already have smoother engagement, but he wanted a turbo for even smoother engagement hoping it would last longer. I don't know. Anecdotal. Maybe I was going off that, and maybe I was going off reports that the auto had problems handling boost. Maybe this and other comments. I don't know, but you are right about the autos holding more.

[86TOYO2k17]

Originally Posted by Irace86.2.0

I believe the AZ6 transmission is rated at 163 tq. The clutch might be more like 180. I'm at a bar of boost on E85 with an Exedy stage 1. No issues so far. I mean, I have 5th gear grind from the previous owner. I think the transmission can obviously hold more, but I don't know over the life of the car. We will see.

Johan who sold me his Harrop kit, said he was switching to a turbo because he blew his auto trans. Autos with a torque converter already have smoother engagement, but he wanted a turbo for even smoother engagement hoping it would last longer. I don't know. Anecdotal. Maybe I was going off that, and maybe I was going off reports that the auto had problems handling boost. Maybe this and other comments. I don't know, but you are right about the autos holding more.

AZ6 is rated 250nm/184ft lbs according to manufacturer.

Yeah I’ve seen his videos. Doesn’t seem to really know what he’s talking about. Pretty sure he didn't “tune” the auto trans either which over about 240whp is almost a requirement. His car barely broke below 6s after a lot of trial and error.

I had an issue after switching pulleys the 1st time where in auto mode I’d hit limiter before it could shift cutting all power and needing to manually shift about 500rpm earlier then I wanted to actually shift. Told the tuner he tweaked somethings and it fixed the problem to manually shift about 275-300rpm early in manual and auto was perfectly fine. Which seemed to be one of his big complaints in the video. Valve body sped it up to about 200rpm and drastically improved shift speed almost instantaneous shifts.

My setup was easily hitting sub 5s with zero issues. Never got to test it’s most recent form. With Dragy I think a 4.5 (1ft rollout) was possible or 4.7 true. Did 4.7(1ft)/4.9 true a few times in the summer before switching/adding a few mods. All seasons on the street can’t launch at all. To be fair after getting around 5.5s i got a valve body and trans cooler before upping the power. But had no issues either way.

But plenty of boosted autos in the forum’s haven’t really seen anyone with issues especially on a daily. One guy with a built FA pushing 400whp overheated his trans on the track. Otherwise tons of “success” stories.