40R on Supra vs. 40R on EVO

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EVOlutionary

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Apr 30, 2008
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A little background. I have spent 10 times as much time doing research on EVOs (that is, one the EVO forums) as I've spent on the Supra forums. That is beginning to shift. . .

One thing that I've noticed is the difference between turbo performance on the 4G63 EVO motor as compared to the 1JZ or 2JZ Supra motor. Seems as though a 35R is considered a BIG street turbo on the EVO and a small to medium sized turbo on the Supra, and a 40R or 42R is an exclusive top end drag turbo on the EVO and a good highway turbo on the Supra.

My question is - why does a 35R on a stroked 2.3 or 2.4L EVO revving to 8K react so differently than the same turbo on a 2.5L 1JZ revving to 8K?? Seems like one can expect it to spool about 1000 rpm sooner on the 1JZ motor as compared to the 4G63/4G64 motor. . . but on an EVO it will make 500whp on pump gas and 650 whp on race gas but less power on a Supra. . .

If I am way off base please let me know. I'm still learning the ins and outs of the JZ powerplants. . .

EVOlutionary
 
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figgie

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Mar 30, 2005
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That is actually a good question.


The answer lies within simple science really and math.

DISPLACEMENT.

Power is based on air flow.

In other words 500 hp in a 4g63, 500 hp on a 2jz, or 500hp on a LS7 will requires roughly the same amount of air flow (55 lbs/min). To get those 55 lbs/min requires more rpm for a smaller displacement or LESS rpm in higher displacement ;)

math(assume 100% efficency in all cases along with the same density).


on the 4g63 2.3L engine @ 4000 rpm. The engine will be pumping 4600L/min
on the 2jz 3.0L engine @ 4000 rpm. The engine will be pumping 6000L/min
on the LS7 7.0L engine @ 4000 rpm. The engine will be pumping 14000L/min
on the V10 8.4L engine @ 4000 rpm. The engine will be pumping 16800L/min

so for the 4g63 to move as much air as the 8.4L engine requires the 4g63 engine spin to 14608 (N/A).

Those pumping numbers are crucial for turbos as the higher displacement engine can move alot more air in the lower RPM portion and as such require less time to achieve a good pressure ratio to spin turbos.
 
tissimo

tissimo

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Supra owners are less crazy then evo owners. 18 is high boost on pump gas on a supra (compared to the 30 i've seen on evos) and 28-30 is high boost on a supra (vs 40+ on a evo). :rofl:

The biggest difference on a 2.3 4g63 vs a 2.5L 1jz is head flow though.
 
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figgie

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tissimo;1155075 said:
Supra owners are less crazy then evo owners. 18 is high boost on pump gas on a supra (compared to the 30 i've seen on evos) and 28-30 is high boost on a supra (vs 40+ on a evo). :rofl:

The biggest difference on a 2.3 4g63 vs a 2.5L 1jz is head flow though.
Click to expand...


well it kind of has nothing to do with "plenum pressure" :)


To get 600 Hp on

7m, requires roughly about 347 kpa (20 Psig)
1j, requires roughly about 530 kpa (38 Psig)
LS7 requires roughly about 158 kpa (1.1 Psig)

the head flow actually takes away from the 100% efficency that I said had to be assumed making the numbers I quoted way off. It can be done but the engines VE at every single point would need to be known.
 
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figgie

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tissimo;1155240 said:
I think it does.
Click to expand...


nope it does not.

Again. VOLUME not pressure. The pressure is the by product of the amount of volume trying to get into the cylinder. The EVO guys might run 30 psi on pump gas but they are pushing that with what turbo?? ;)

It literally is simple. More displacement less plenum pressure.

Most V8 guys don't not tune past 8psi-11psi on pump gas!

Now again, the head will effect the motor efficency (VE) and hence forth will make the turbo either surge, go into a more efficent/inefficent zone depending on where the turbo is sized. If the turbo is in a more efficent zone than in another motor.. guess what happens. You can run higher plenum pressure (related to Volume) than in another car.

Now on the EVO front and the GT35r..... 650 whp on that turbo is spinning that sucker to oblivion. Specifically past the 116k redline that garret has. Just because some acheives a 1/4 mile time of 5 seconds by throwing a car of a cliff is not a good thing ;)
 
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jblaze

"Always the underdog"
Apr 14, 2006
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I don't agree with this at all, and I'll tell you why. I have a friend that made 431rwhp on a Mustang Dyno ( which reads at a 15% loss as recorded by the Dyno tuner). This equates to just under 500rwhp @ 17 psi. This was on a MA70 w/ a GT35R. I think each situation is different. Also Supras have more torque which in turn creates satisfaction. You can have all the Hp you want but without torque, you just reinvented VTEC! And I guess it goes back to what makes you happy. A smaller motor will have to rev to get the power so pushing it lightly is not an option. Supras can put down (i've seen) as much as 600rwhp on pump. Now most guys I know do not push it that hard. Its not saying that they can't make the power, they are also looking at longevity..
 
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figgie

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jblaze;1155255 said:
I don't agree with this at all, and I'll tell you why. I have a friend that made 431rwhp on a Mustang Dyno ( which reads at a 15% loss as recorded by the Dyno tuner). This equates to just under 500rwhp @ 17 psi. This was on a MA70 w/ a GT35R. I think each situation is different. Also Supras have more torque which in turn creates satisfaction. You can have all the Hp you want but without torque, you just reinvented VTEC! And I guess it goes back to what makes you happy. A smaller motor will have to rev to get the power so pushing it lightly is not an option. Supras can put down (i've seen) as much as 600rwhp on pump. Now most guys I know do not push it that hard. Its not saying that they can't make the power, they are also looking at longevity..
Click to expand...

hmm intresting

if that is the case..

seems like the VE of the 7m is around 84% give or take 2%. :)
 
tissimo

tissimo

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figgie;1155251 said:
nope it does not.

Again. VOLUME not pressure. The pressure is the by product of the amount of volume trying to get into the cylinder. The EVO guys might run 30 psi on pump gas but they are pushing that with what turbo?? ;)

It literally is simple. More displacement less plenum pressure.

Most V8 guys don't not tune past 8psi-11psi on pump gas!

Now again, the head will effect the motor efficency (VE) and hence forth will make the turbo either surge, go into a more efficent/inefficent zone depending on where the turbo is sized. If the turbo is in a more efficent zone than in another motor.. guess what happens. You can run higher plenum pressure (related to Volume) than in another car.

Now on the EVO front and the GT35r..... 650 whp on that turbo is spinning that sucker to oblivion. Specifically past the 116k redline that garret has. Just because some acheives a 1/4 mile time of 5 seconds by throwing a car of a cliff is not a good thing ;)
Click to expand...

Maybe we're not looking at the same post?
 
suprahero

suprahero

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My gt35r made 501 @ 18psi with my 1.5jz, but I don't have the stock head that Figgie is referring too.

By the way, I don't have a physics and math background. My background is more in the line of redneckology........:biglaugh:
 
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foreverpsycotic

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Jul 16, 2006
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figgie;1155822 said:
I am trying to check some VE values and the numbers are coming in super low for the 7m.
Click to expand...

Well, it is at minimum a 16 year old head (sans buying one new from toyota), that was designed over 20 years ago. It is entirely possible that it is not as efficient as we would want it to be.
 
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