Turbo vs NA

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Turbo vs NA

Postby Clouds » Sun Jan 04, 2015 4:34 pm

To those of you who have turbo'd their cars, do you guys miss anything from your car that was there when it was naturally aspirated?

Maybe, like fuel efficiency or the original powerband.
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Re: Turbo vs NA

Postby Moto_Club4AG » Sun Jan 04, 2015 7:29 pm

Clouds wrote:To those of you who have turbo'd their cars, do you guys miss anything from your car that was there when it was naturally aspirated?

Maybe, like fuel efficiency or the original powerband.


Crisp engine response. That's the biggest thing you'd lose from a very responsive engine like a 5valve, VVT, 4A-GE.


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Re: Turbo vs NA

Postby sirdeuce » Mon Jan 05, 2015 1:47 pm

Only way you'll know if you like it is to try it. I tried baloot once, found I didn't like it.
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Re: Turbo vs NA

Postby ae90tuner » Tue Jan 06, 2015 10:14 am

This isn't about the ae86, and it may be different from an NA-T setup. I had an sw20 turbo that was fairly quick, but when I first test drove my beater Paseo it felt so much more enjoyable even though it was way slower. The way the NA engine responds is just something so nice, even though the 5efe lacked almost everything the 3sgte had, it was responsive and was a good change.

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Re: Turbo vs NA

Postby 86 Corolla » Tue Jan 06, 2015 9:49 pm

I have both forms. From my novice driving experience, each has its own pluses and minuses. Turbo G-pull is awesome and will get you there faster, but where are you going next? NA will get you there later either because you still want drive some more and enjoy more of the responsiveness & sound or because you are simply slow =P

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Re: Turbo vs NA

Postby yoshimitsuspeed » Wed Jan 07, 2015 12:06 am

One of the best things about turbo is that fuel that it doesn't effect fuel efficiency at least if you drove the same as you did before. In some situations it can even improve efficiency. For example the 4AGE and GZE ECUs go into open loop at high throttle. At 3000 RPM it may take 80% throttle to go into open loop. At redline it may take about 20% throttle to go into open loop.
If you are driving your stock NA 4A up a hill and need to downshift to third and use 60% throttle at 4500 RPM you will likely be in open loop. This means the engine drops out of stoich and runs much richer.
Motors generally get their best BSFC at lower RPM as well.
So slap a turbo on that same motor and now you are able to climb the same hill in fourth at 3000 RPM and 40% throttle you will probably still be in closed loop maintaining stoich AFRs. Combined with the improved BSFC at the lower RPM and you will actually get better gas mileage.

As for the power band I don't know how you can miss more of something.
For example I drove my blacktop for 6 months with the wastegate disconnected while I dialed everything in. I loved the motor and for a DD was quite happy with how well it did. Finally when the time came to hook up the turbo it was nothing but as much or more everywhere. Off boost it's the same motor. When the turbo kicks in it's just 50% more of what it was before. It's like getting punched in the back by a jet airplaine. IMO there is nothing better.

Yes at lower RPM there is lag but if you learn how to drive around that it's not an issue. From a performance standpoint it's not a handicap which really just brings it down to driver enjoyment and adaptability. If you can figure out how to make a turbo do what you want it's a beautiful thing. It just takes a little more forethought. But then that is a sign of a good driver. NA or boost when a race driver enters a corner they already know 98% of how steering and throttle will be when they exit the corner. In a situation like this you just add more gas a couple tenths or hundredths of a second before you would on the NA car so that boost is coming on and power is there when you need it.

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Re: Turbo vs NA

Postby burdickjp » Wed Jan 07, 2015 10:09 am

yoshimitsuspeed wrote:One of the best things about turbo is that fuel that it doesn't effect fuel efficiency at least if you drove the same as you did before. In some situations it can even improve efficiency. For example the 4AGE and GZE ECUs go into open loop at high throttle. At 3000 RPM it may take 80% throttle to go into open loop. At redline it may take about 20% throttle to go into open loop.


Have you tested this? I've never seen an OEM ECU stay in closed loop at 80% throttle.

All of this closed loop/open loop talk goes out the window when you USE and EMS and can set up an AFR table. You get exactly what you want where and when you want it.
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Re: Turbo vs NA

Postby yoshimitsuspeed » Wed Jan 07, 2015 10:21 am

burdickjp wrote:
yoshimitsuspeed wrote:One of the best things about turbo is that fuel that it doesn't effect fuel efficiency at least if you drove the same as you did before. In some situations it can even improve efficiency. For example the 4AGE and GZE ECUs go into open loop at high throttle. At 3000 RPM it may take 80% throttle to go into open loop. At redline it may take about 20% throttle to go into open loop.


Have you tested this? I've never seen an OEM ECU stay in closed loop at 80% throttle.

All of this closed loop/open loop talk goes out the window when you USE and EMS and can set up an AFR table. You get exactly what you want where and when you want it.


Yes I have tested this. The percentage is a rough guess but at low RPM it takes a lot more throttle to get it into open loop than it does at high RPM.

Yes it's true that things change as far as open/closed loop if you go to EMS but unless you drive like an ahole your gas mileage will stay about the same NA or turbo.

Another way to look at it would be like the Top Gear thirsty Prius challenge.
If you had a 150 WHP NA 4A that had to drive as fast as it possibly could and if you had a 250 WHP 4A that just had to keep up with it then it's extremely likely the NA 4A would run out of gas first. If both were on EMS and tuned to be absolutely as efficient as possible they would probably be very close.

The point is that if you double your HP but drive the same, accelerate the same and go the same speed you should get similar gas mileage.
If it's an extreme build where say you went with 8:1 compression and 272 cams on the boosted motor it would sway things a lot more in the NA motors favor but that's why I hate low comp and love high comp low boost builds.
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Re: Turbo vs NA

Postby ae90tuner » Wed Jan 07, 2015 8:43 pm

yoshimitsuspeed wrote:As for the power band I don't know how you can miss more of something.
For example I drove my blacktop for 6 months with the wastegate disconnected while I dialed everything in. I loved the motor and for a DD was quite happy with how well it did. Finally when the time came to hook up the turbo it was nothing but as much or more everywhere. Off boost it's the same motor. When the turbo kicks in it's just 50% more of what it was before. It's like getting punched in the back by a jet airplaine. IMO there is nothing better.


A low compression turbo to an NA engine is what im talking about and is quite different, NA-T may very well have the best of both worlds, but my 3sgte with a ct27 wasn't that impressive as far as response went. My buddies d16 with a bolt on turbo kit does feel as you describe with the feeling like NA and the turbo adding more. I do wonder though with the high comp turbo setup's if there is more risk even with a proper tune?

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Re: Turbo vs NA

Postby yoshimitsuspeed » Thu Jan 08, 2015 10:34 am

ae90tuner wrote:A low compression turbo to an NA engine is what im talking about and is quite different, NA-T may very well have the best of both worlds, but my 3sgte with a ct27 wasn't that impressive as far as response went. My buddies d16 with a bolt on turbo kit does feel as you describe with the feeling like NA and the turbo adding more. I do wonder though with the high comp turbo setup's if there is more risk even with a proper tune?


Response is a funny word that always raises my hackles. It's almost as bad as backpressure.
Okay not quite because backpressure is bad. Response is just something that people worry about way too much.

First we need to determine exactly what we mean. Response generally applies to throttle response but some also tie that into lag on a turbo.
Either way it's just not that big a deal unless it's really bad or you are trying to win a very aggressive series of racing where milliseconds actually count.
The actual throttle response of the 3SGTE should be the same as a beams or any other similar motor with the throttle body located a similar distance away from the intake valves. This is why people rave about ITBs. It puts the throttle plate right next to the intake valves. OMG the response. You are talking about milliseconds. You are talking about the kind of response that after a 10 lap race might mean you cross the finish line 2/10ths quicker.
In a blind study I would be willing to bet that no one wold be able to feel the difference by the seat of their pants. Even the GZE that has several feet and gallons of volume between the throttle plate and intake has very quick response.
More importantly it's learning how to drive that particular setup. If your motor takes 10 milliseconds more for the air to get from the TB to the head then you step on the gas 10 ms sooner.
The same applies to driving a turbo. If you drive with forethought and strategy then lag is very rarely a handicap. Even when it could be there are techniques like left foot braking or other strategies that make it really not.

But yes, more compression should help the turbo spool a little quicker.

More risk is really relative.
More compression does mean a narrower margin for error.
On the other hand if you were running a high compression motor with a wideband, pyrometer and good knock monitoring you would be safer than running low comp without those things.

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Re: Turbo vs NA

Postby ae90tuner » Fri Jan 09, 2015 8:24 am

I guess this comes down to preference, having owned a gen 3 3sge, beams 3sge and a 2nd gen 3sgte I can say I enjoy the beams 3sge the most. And I agree it comes down to learning how to drive your setup, I'm no race car driver so its not like some kind of sponsor will just hand me a car and say "here drive it" and I'd have no choice but to drive it regardless of aspiration. So I guess as tuners and enthusiast we have the choice to be a little picky on how we want our own cars setup. On a side note the reason I asked about the high comp turbo setup is cause I've thought about turboing the beams many times (7psi on a gt28), but i'm also considering doing a 2grfe.

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Re: Turbo vs NA

Postby ToeKnee805 » Fri Jan 09, 2015 8:09 pm

i miss the normal idle, and my car not smelling like ass! other than that i love my turbo setup
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Re: Turbo vs NA

Postby yoshimitsuspeed » Sat Jan 10, 2015 10:48 am

ToeKnee805 wrote:i miss the normal idle, and my car not smelling like ass! other than that i love my turbo setup


Neither of those things have to do with turbos. What's wrong with your car?

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Re: Turbo vs NA

Postby Clouds » Sat Jan 10, 2015 11:56 am

yoshimitsuspeed wrote:
ToeKnee805 wrote:i miss the normal idle, and my car not smelling like ass! other than that i love my turbo setup


Neither of those things have to do with turbos. What's wrong with your car?

:lol:
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Re: Turbo vs NA

Postby IndiaDorifto7 » Mon Jan 12, 2015 3:54 pm

Turbo sounds awesome, but I think supercharging is also a viable option. It's much cheaper and easier to do and has much less lag, although it doesn't give as much power as the turbo.

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Re: Turbo vs NA

Postby oldeskewltoy » Mon Jan 12, 2015 4:06 pm

http://www.roadandtrack.com/car-culture ... ocharging/

from Road and Track Article wrote:Despite the claims of marketers everywhere, lag can't be eliminated. The holy grail for engineers of turbo engines—from the 1962 Oldsmobile Jetfire to today's boosted cars—has been to manage the lag so that it's unobtrusive in normal driving. Some engines do this better than others.....
When you're approaching the handling limit of a well-balanced car, you need precise control of engine output. You may need a quick jolt of torque to induce oversteer or to gradually increase power to keep the car at its limit in a corner. These adjustments need to happen the instant you request them and in direct correlation to pedal input.

A naturally aspirated engine's output is determined by the position of the pedal and the engine speed, period. Turbos change that into a complicated matrix with far too many variables for a driver to keep track of. At best, turbo lag is a handicap. At worst, it turns neutral, throttle-adjustable cars into insolent, uncontrollable, four-wheeled bastards.
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Re: Turbo vs NA

Postby yoshimitsuspeed » Mon Jan 12, 2015 5:30 pm

IndiaDorifto7 wrote:Turbo sounds awesome, but I think supercharging is also a viable option. It's much cheaper and easier to do and has much less lag, although it doesn't give as much power as the turbo.


The only SC that might possibly be a little cheaper is a GZE setup. The amount of time money and energy that it would take is far more than it's worth. If you knew you would be happy with 140 WHP maybe it could make sense in the right situation but there is no way I would ever consider it because of all the cons.
The intake piping is idiotic, everything is harder to access and work on, the SCs are getting rare and expensive, they are not rebuildable, if you ever decide you want more than about 160 WHP you will have to completely redo everything.

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Re: Turbo vs NA

Postby yoshimitsuspeed » Mon Jan 12, 2015 5:35 pm

oldeskewltoy wrote:http://www.roadandtrack.com/car-culture/news/a24691/ferrari-engineers-dont-like-turbocharging/

from Road and Track Article wrote:Despite the claims of marketers everywhere, lag can't be eliminated. The holy grail for engineers of turbo engines—from the 1962 Oldsmobile Jetfire to today's boosted cars—has been to manage the lag so that it's unobtrusive in normal driving. Some engines do this better than others.....
When you're approaching the handling limit of a well-balanced car, you need precise control of engine output. You may need a quick jolt of torque to induce oversteer or to gradually increase power to keep the car at its limit in a corner. These adjustments need to happen the instant you request them and in direct correlation to pedal input.

A naturally aspirated engine's output is determined by the position of the pedal and the engine speed, period. Turbos change that into a complicated matrix with far too many variables for a driver to keep track of. At best, turbo lag is a handicap. At worst, it turns neutral, throttle-adjustable cars into insolent, uncontrollable, four-wheeled bastards.





I held my tongue on your post on the OC but that guy is an idiot and has no business writing for a real car magazine.
That is a 100% opinion puff piece designed to piss off people like me and to make people like you feel justified in your beliefs.

Anyone who would write this.
Turbos change that into a complicated matrix with far too many variables for a driver to keep track of.

Doesn't know enough to be allowed to have an opinion.

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Re: Turbo vs NA

Postby riddleyo » Tue Jan 13, 2015 7:46 pm

I prefer NA to Turbo for autocross. The "response" of an NA allows me to drive on the limit much easier, with more confidence, and with more precise control. Sometimes I don't want the full power the car can make - I want to feather in the throttle to keep traction on the rear wheels and allow acceleration without upsetting the balance of the car. Speaking of upsetting the balance... my turbo sw20 was terrible for learning in autocross. The power would come on too abruptly in the middle of the turn and upset the balance of the car. And in between cones if you try to anticipate the turbo lag by pressing the gas sooner, that means you will start pushing when you don't want to push. Anyway, I have found the turbo more of a hinderance than anything in autocross. It even carries over to the Celica 2zz-ge engine where Toyota engineers designed the lift to pack a wallop of a punch at 6000 rpm when the high lift cam engages. My 2zz felt awesome on the street, but in autocross, it upset the balance of the care more than anything and I could never harness the full potential of the car due to the abrupt onset of power. My 1.6 blacktop NA actually churns out much faster laptimes than my 2zz celica or 3sgte mr2.

Now on the street and on the track, turbo definitely has its perks. If you want to view the power of Turbo vs NA cars, simply watch Tsuchiya in this Hot Version NA vs Turbo battle at the Ebisu.
https://www.youtube.com/watch?v=bHtgnZIxNHc

Spoiler alert:
The NA cars lose. Although the lightweight NA MR2 held the lead for most of the race, the turbos mop up at the end. The NA can dive deep into the corner, but the turbo pulls away on the straights.

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Re: Turbo vs NA

Postby Clouds » Wed Jan 14, 2015 8:49 am

riddleyo wrote:I prefer NA to Turbo for autocross. The "response" of an NA allows me to drive on the limit much easier, with more confidence, and with more precise control. Sometimes I don't want the full power the car can make - I want to feather in the throttle to keep traction on the rear wheels and allow acceleration without upsetting the balance of the car. Speaking of upsetting the balance... my turbo sw20 was terrible for learning in autocross. The power would come on too abruptly in the middle of the turn and upset the balance of the car. And in between cones if you try to anticipate the turbo lag by pressing the gas sooner, that means you will start pushing when you don't want to push. Anyway, I have found the turbo more of a hinderance than anything in autocross. It even carries over to the Celica 2zz-ge engine where Toyota engineers designed the lift to pack a wallop of a punch at 6000 rpm when the high lift cam engages. My 2zz felt awesome on the street, but in autocross, it upset the balance of the care more than anything and I could never harness the full potential of the car due to the abrupt onset of power. My 1.6 blacktop NA actually churns out much faster laptimes than my 2zz celica or 3sgte mr2.

Now on the street and on the track, turbo definitely has its perks. If you want to view the power of Turbo vs NA cars, simply watch Tsuchiya in this Hot Version NA vs Turbo battle at the Ebisu.
https://www.youtube.com/watch?v=bHtgnZIxNHc

Spoiler alert:
The NA cars lose. Although the lightweight NA MR2 held the lead for most of the race, the turbos mop up at the end. The NA can dive deep into the corner, but the turbo pulls away on the straights.

I think that I actually watched that episode just yesterday. Hot Version is the best.
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Re: Turbo vs NA

Postby ae90tuner » Wed Jan 14, 2015 6:25 pm

riddleyo wrote:I prefer NA to Turbo for autocross. The "response" of an NA allows me to drive on the limit much easier, with more confidence, and with more precise control. Sometimes I don't want the full power the car can make - I want to feather in the throttle to keep traction on the rear wheels and allow acceleration without upsetting the balance of the car. Speaking of upsetting the balance... my turbo sw20 was terrible for learning in autocross. The power would come on too abruptly in the middle of the turn and upset the balance of the car. And in between cones if you try to anticipate the turbo lag by pressing the gas sooner, that means you will start pushing when you don't want to push. Anyway, I have found the turbo more of a hinderance than anything in autocross. It even carries over to the Celica 2zz-ge engine where Toyota engineers designed the lift to pack a wallop of a punch at 6000 rpm when the high lift cam engages. My 2zz felt awesome on the street, but in autocross, it upset the balance of the care more than anything and I could never harness the full potential of the car due to the abrupt onset of power. My 1.6 blacktop NA actually churns out much faster laptimes than my 2zz celica or 3sgte mr2.

Now on the street and on the track, turbo definitely has its perks. If you want to view the power of Turbo vs NA cars, simply watch Tsuchiya in this Hot Version NA vs Turbo battle at the Ebisu.
https://www.youtube.com/watch?v=bHtgnZIxNHc

Spoiler alert:
The NA cars lose. Although the lightweight NA MR2 held the lead for most of the race, the turbos mop up at the end. The NA can dive deep into the corner, but the turbo pulls away on the straights.



I believe on that particular video Orido slowed down to show the difference in the acceleration and cornering of turbo and NA cars. Had he just went all out and not bother to slow down the other cars where not catching up to him. The track layout had a lot to do with giving the mr-s the advantage.

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Re: Turbo vs NA

Postby Clouds » Thu Jan 15, 2015 8:32 am

Orido was driving the RX-7, right?
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Re: Turbo vs NA

Postby ae90tuner » Thu Jan 15, 2015 12:42 pm

Clouds wrote:Orido was driving the RX-7, right?


Orido was driving the 2zzge mr-s.

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Re: Turbo vs NA

Postby yoshimitsuspeed » Thu Jan 15, 2015 4:08 pm

All that video shows is that big heavy and more powerful cars don't do as well on that track. It has absolutely nothing to do with turbo vs NA.
Throw the S2k and MRs on a track with a turbocharged version of each and see who wins. That would be a direct comparison and the turbo version would win every time.

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Re: Turbo vs NA

Postby ToeKnee805 » Thu Jan 15, 2015 7:31 pm

yoshimitsuspeed wrote:
ToeKnee805 wrote:i miss the normal idle, and my car not smelling like ass! other than that i love my turbo setup


Neither of those things have to do with turbos. What's wrong with your car?



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Re: Turbo vs NA

Postby yoshimitsuspeed » Fri Jan 16, 2015 10:42 am

ToeKnee805 wrote:
My rich tune :lol:


At idle?

Turbo or not you should be running stoich at idle and cruise.

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Re: Turbo vs NA

Postby ToeKnee805 » Fri Jan 16, 2015 9:42 pm

yessir, im idling at 12ish, drops down to 10:1 WOT, and stoich to a bit lean on cruising.
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Re: Turbo vs NA

Postby yoshimitsuspeed » Fri Jan 16, 2015 10:21 pm

Wow lean that thing out. Should be like 15:1 idle.
10:1 is also like nutty rich unless you have some sort of crazy build. You are leaving a lot of power on the table and wasting a lot of gas at 10:1.

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Re: Turbo vs NA

Postby ToeKnee805 » Sat Jan 17, 2015 10:23 pm

I got it tuned without really knowing much about how lean i could go on a 3rib with rebuilt internals and slightly bumped up compression (decked block, shaved head) So i had them just do something conservative that wont blow me up. Currently im making 125hp, 150wtq, and when i open up my exhaust cutout i am at 150hp, 163wtq.

I contacted you about a manifold, so as soon as i can get that in, and a new downpipe made to allow for better flow i am getting a re-tune.

Im running stock wastegate 7lbs of boost, rebuilt internals, 3rib, TVIS activated, 440cc injectors, and a MSPNP. From your experience how lean can i go without detonating or blowing my engine up.
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Re: Turbo vs NA

Postby yoshimitsuspeed » Mon Jan 19, 2015 9:28 am

ToeKnee805 wrote:I got it tuned without really knowing much about how lean i could go on a 3rib with rebuilt internals and slightly bumped up compression (decked block, shaved head) So i had them just do something conservative that wont blow me up. Currently im making 125hp, 150wtq, and when i open up my exhaust cutout i am at 150hp, 163wtq.

I contacted you about a manifold, so as soon as i can get that in, and a new downpipe made to allow for better flow i am getting a re-tune.

Im running stock wastegate 7lbs of boost, rebuilt internals, 3rib, TVIS activated, 440cc injectors, and a MSPNP. From your experience how lean can i go without detonating or blowing my engine up.


It totally depends on many other things and even the engine. Two different people could run two identical setups in two motors that should be the same and they could both experience completely different results.

With that said you shouldn't really be using AFRs to protect from detonation. You would want to use boost, timing and compression to protect from detonation while aiming for a good target AFR.
The big thing is that your AFRs should be stoich or even a hair leaner when idling. It's odd that they are not.
For all but the most extreme or unique builds I would aim leaner. On a moderately high power build I would look for around 13:1 around 3k RPM 12.5ish by 4500 and at the richest 12:1 by redline.

With that said if you don't have the proper monitoring equipment then running that rich AFR may be protecting you from a problem you wouldn't know about if it surfaced.
IMO the most important thing is to be running the right monitoring. With good knock monitoring and a pyrometer you can push the limits much further while still being much safer than you would be without monitoring knock or EGTs.

Also your refrence to power and torque is confusing because you don't specify WHP but you do specify WTQ. WTQ is irrelevant because it depends what gear you are in.
Do you mean WHP?