G37 Dyno Up on Automobilemag.com 50+ HP
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From: long island
Originally Posted by Pearlcoupeg35
HAHAHAHA....couldnt have posted it better myself Jimmy!
I might just never buy a car again and just look at all the **** coming out....its like cell phones & sh#t now. You think you got the hottest thing and then a week later its old news.
I might just never buy a car again and just look at all the **** coming out....its like cell phones & sh#t now. You think you got the hottest thing and then a week later its old news.
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I'm confused -- this article states the fuel cut-off for the 2007 G35 Coupe 6mt is 6600rpm. In my 2006 Coupe 6mt, the redline is 7100 and the fuel cut off seems to be at around 7300rpm.
What gives? Are they padding the G37 comparison by under-testing the 2007 G35 Coupe? The fuel-cutoff they quote is more likely for an automatic than a 6mt.
What gives? Are they padding the G37 comparison by under-testing the 2007 G35 Coupe? The fuel-cutoff they quote is more likely for an automatic than a 6mt.
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That still does not compute -- the 6mt will allow you to redline 4th gear @ 7100+ without any fuel cut... in fact, it will allow you to shift into 5th and continue accelerating to the 157mph drag limited top speed.
The dyno pull was in 4th right? Regardless, unless it was in 6th, it doesn't add up.
The dyno pull was in 4th right? Regardless, unless it was in 6th, it doesn't add up.
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From: Caribbean
[6/11/07 edit= this data isnt very accurate, data has been improved in subsequent postings]
comparing the g37 to the 335i, i posted the following on another forum. not sure if anyone here is interested, but here it is:
comparing the g37 to the 335i, i posted the following on another forum. not sure if anyone here is interested, but here it is:
Originally Posted by tekknikal
i tried to calculate the hp @ every rpm, and picked gears based on gearing and looking at the dyno. i assumed that you'd want to hold each gear to redline. in the case of the 335i, that might not be the best move because the power drops at upper rpms...but i didnt do any sort of analysis to figure out if the power loss at lower rpms was small enough to justify the gains of short shifting. in the case of the g, that definitely seems to be the way to go.
anyway here's what i found:
the 335i data is roughly estimated as i came up with a more accurate way to calculate the whp on the g after i had already put in the 335i data. (i will go back and redo the 335 data tomorrow)
i tried to remove bias from the #s and rounded up if i was in doubt (on the 335). i think the #s there are accurate +/-5whp or less...but either way i think it gives a fair idea of what's going on. what i took from this is that:
1. its a close race, especially when you consider the 335 is ~100lbs lighter
2. if a g37 driver wants to have max advantage, he should start at 55mph or so....
3. if a 335i driver wanted to have max advantage, he should start as slow as possible, find out if its a good idea to short shift, but most preferably get chipped.
4. an average 335 driver could be a problem for an average g37 driver because the 335 doesnt seem to be as sensitive to shifting mistakes as the g...for instance, short shifting in the g carries a large penalty while in the 335 the engine makes good hp and tq lower down. obviously you wouldnt want to make the mistake in either car, but at a glance that's what it looks like...i could be wrong here though
oh and imo the g37 should have had a 3.9FD. they probably didnt do it for fuel economy. i think that g37 with that FD would move through the gears as quick as a nonrevup 6mt G...which isnt bad at all, especially considering the gains.
finally someone correct me/question me if im wrong (or you think i am)!
anyway here's what i found:
the 335i data is roughly estimated as i came up with a more accurate way to calculate the whp on the g after i had already put in the 335i data. (i will go back and redo the 335 data tomorrow)
i tried to remove bias from the #s and rounded up if i was in doubt (on the 335). i think the #s there are accurate +/-5whp or less...but either way i think it gives a fair idea of what's going on. what i took from this is that:
1. its a close race, especially when you consider the 335 is ~100lbs lighter
2. if a g37 driver wants to have max advantage, he should start at 55mph or so....
3. if a 335i driver wanted to have max advantage, he should start as slow as possible, find out if its a good idea to short shift, but most preferably get chipped.
4. an average 335 driver could be a problem for an average g37 driver because the 335 doesnt seem to be as sensitive to shifting mistakes as the g...for instance, short shifting in the g carries a large penalty while in the 335 the engine makes good hp and tq lower down. obviously you wouldnt want to make the mistake in either car, but at a glance that's what it looks like...i could be wrong here though
oh and imo the g37 should have had a 3.9FD. they probably didnt do it for fuel economy. i think that g37 with that FD would move through the gears as quick as a nonrevup 6mt G...which isnt bad at all, especially considering the gains.
finally someone correct me/question me if im wrong (or you think i am)!
Last edited by tekknikal; Jun 11, 2007 at 12:52 PM.
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Great work.
I performed the same thing, but only got as far as spreadsheet format (no graphing). I posted my spreadsheet here previously.
In terms of comments:
1. Just like my calc, your chart is only "dyno" hp at engine/transmission ratio of 1:1. This can be deceiving as the power to the ground is multiplied depending on gearing. This is why you always have a drop off in power when you shift gears. You just don't see that on a dyno because it is taken at only the 1:1 gear. You shouldn't short shift almost any car, even this 335. It's a good exercise nonetheless and the same method I used.
2. At the shift points of both cars, shouldn't the graph show a straight line down to the HP figure in the next gear (meaning at the same MPH, you have 2 HP points - one at the redline of the previous gear and one at the beginning of the next gear)? The shift points I calculated for these 2 cars is: G37 - 42, 69, 99, 127. 335 - 42, 71, 107, 142. The chart you have shows a linear angled line in the last 5 mph going down to the shift point. This might be deceiving when analyzing the graph. In fact, the 335 lines show a drop in HP right up to redline (which is true) and then the next gear just picks up from there. In actuality, according to my same calc, there is a drop in HP as you shift into 2nd, and a rise in HP as you shift into 3rd and 4th.
3. Something doesn't look right with the G37 curve from 100-110 mph. It goes down and then up and then down again. All within 10 mph.
Do you agree with the above? Not to make work for you, but if the comments are valid - I'd like to see what the graph looks like corrected.
Good work again.
I performed the same thing, but only got as far as spreadsheet format (no graphing). I posted my spreadsheet here previously.
In terms of comments:
1. Just like my calc, your chart is only "dyno" hp at engine/transmission ratio of 1:1. This can be deceiving as the power to the ground is multiplied depending on gearing. This is why you always have a drop off in power when you shift gears. You just don't see that on a dyno because it is taken at only the 1:1 gear. You shouldn't short shift almost any car, even this 335. It's a good exercise nonetheless and the same method I used.
2. At the shift points of both cars, shouldn't the graph show a straight line down to the HP figure in the next gear (meaning at the same MPH, you have 2 HP points - one at the redline of the previous gear and one at the beginning of the next gear)? The shift points I calculated for these 2 cars is: G37 - 42, 69, 99, 127. 335 - 42, 71, 107, 142. The chart you have shows a linear angled line in the last 5 mph going down to the shift point. This might be deceiving when analyzing the graph. In fact, the 335 lines show a drop in HP right up to redline (which is true) and then the next gear just picks up from there. In actuality, according to my same calc, there is a drop in HP as you shift into 2nd, and a rise in HP as you shift into 3rd and 4th.
3. Something doesn't look right with the G37 curve from 100-110 mph. It goes down and then up and then down again. All within 10 mph.
Do you agree with the above? Not to make work for you, but if the comments are valid - I'd like to see what the graph looks like corrected.
Good work again.
Last edited by muscarel; Jun 6, 2007 at 07:17 PM.
I am not sure if anyone had mention this but the G37 dyno results look almsot identical to the M3 dyno. Look at the torque and hp curve. Almost the same. Below is the M3 dyno chart:
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From: Caribbean
Originally Posted by muscarel
Great work.
I performed the same thing, but only got as far as spreadsheet format (no graphing). I posted my spreadsheet here previously.
In terms of comments:
1. Just like my calc, your chart is only "dyno" hp at engine/transmission ratio of 1:1. This can be deceiving as the power to the ground is multiplied depending on gearing. This is why you always have a drop off in power when you shift gears. You just don't see that on a dyno because it is taken at only the 1:1 gear. You shouldn't short shift almost any car, even this 335. It's a good exercise nonetheless and the same method I used.
2. At the shift points of both cars, shouldn't the graph show a straight line down to the HP figure in the next gear (meaning at the same MPH, you have 2 HP points - one at the redline of the previous gear and one at the beginning of the next gear)? The shift points I calculated for these 2 cars is: G37 - 42, 69, 99, 127. 335 - 42, 71, 107, 142. The chart you have shows a linear angled line in the last 5 mph going down to the shift point. This might be deceiving when analyzing the graph. In fact, the 335 lines show a drop in HP right up to redline (which is true) and then the next gear just picks up from there. In actuality, according to my same calc, there is a drop in HP as you shift into 2nd, and a rise in HP as you shift into 3rd and 4th.
3. Something doesn't look right with the G37 curve from 100-110 mph. It goes down and then up and then down again. All within 10 mph.
Do you agree with the above? Not to make work for you, but if the comments are valid - I'd like to see what the graph looks like corrected.
Good work again.
I performed the same thing, but only got as far as spreadsheet format (no graphing). I posted my spreadsheet here previously.
In terms of comments:
1. Just like my calc, your chart is only "dyno" hp at engine/transmission ratio of 1:1. This can be deceiving as the power to the ground is multiplied depending on gearing. This is why you always have a drop off in power when you shift gears. You just don't see that on a dyno because it is taken at only the 1:1 gear. You shouldn't short shift almost any car, even this 335. It's a good exercise nonetheless and the same method I used.
2. At the shift points of both cars, shouldn't the graph show a straight line down to the HP figure in the next gear (meaning at the same MPH, you have 2 HP points - one at the redline of the previous gear and one at the beginning of the next gear)? The shift points I calculated for these 2 cars is: G37 - 42, 69, 99, 127. 335 - 42, 71, 107, 142. The chart you have shows a linear angled line in the last 5 mph going down to the shift point. This might be deceiving when analyzing the graph. In fact, the 335 lines show a drop in HP right up to redline (which is true) and then the next gear just picks up from there. In actuality, according to my same calc, there is a drop in HP as you shift into 2nd, and a rise in HP as you shift into 3rd and 4th.
3. Something doesn't look right with the G37 curve from 100-110 mph. It goes down and then up and then down again. All within 10 mph.
Do you agree with the above? Not to make work for you, but if the comments are valid - I'd like to see what the graph looks like corrected.
Good work again.
anyway good point on the gearing. i hadnt thought of it. i accounted for the gearing to calculate the shift pts but never multiplied it back... ill do that in the next revision. about the hp changes...i only chartd this for every 5mph because i couldnt do it for ~100 data pts, so thats why the 'accurate resolution' is so low. thanks for pointing out the g37 curve @ 105 area... ill take another look at it. ill see if i can account for all of this when i work on it again, hopefully we can have a more accurate chart to look at. the effect on gearing in particular may be interesting
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In terms of comparisions with the M3, the M3 weighs less and the gearing seems more aggressive, at least in 1st gear. Final drive ratio is almost the same, but look at the 1st gear ratio of the M3 compared to 3.79 of the G37. G37 tire size is also a 1/2 inch taller:
1st Gear Ratio 4.23:1
2nd Gear Ratio 2.53:1
3rd Gear Ratio 1.67:1
4th Gear Ratio 1.23:1
5th Gear Ratio 1.00:1
6th Gear Ratio 0.83:1
Final Drive Ratio 3.62:1
That being said, it's nice that Infiniti could produce an engine with similar characteristics as that of the E46 M3. Then again, BMW did it with a 3.2 liter engine.
1st Gear Ratio 4.23:1
2nd Gear Ratio 2.53:1
3rd Gear Ratio 1.67:1
4th Gear Ratio 1.23:1
5th Gear Ratio 1.00:1
6th Gear Ratio 0.83:1
Final Drive Ratio 3.62:1
That being said, it's nice that Infiniti could produce an engine with similar characteristics as that of the E46 M3. Then again, BMW did it with a 3.2 liter engine.
Originally Posted by muscarel
In terms of comparisions with the M3, the M3 weighs less and the gearing seems more aggressive, at least in 1st gear. Final drive ratio is almost the same, but look at the 1st gear ratio of the M3 compared to 3.79 of the G37. G37 tire size is also a 1/2 inch taller:
1st Gear Ratio 4.23:1
2nd Gear Ratio 2.53:1
3rd Gear Ratio 1.67:1
4th Gear Ratio 1.23:1
5th Gear Ratio 1.00:1
6th Gear Ratio 0.83:1
Final Drive Ratio 3.62:1
That being said, it's nice that Infiniti could produce an engine with similar characteristics as that of the E46 M3. Then again, BMW did it with a 3.2 liter engine.
1st Gear Ratio 4.23:1
2nd Gear Ratio 2.53:1
3rd Gear Ratio 1.67:1
4th Gear Ratio 1.23:1
5th Gear Ratio 1.00:1
6th Gear Ratio 0.83:1
Final Drive Ratio 3.62:1
That being said, it's nice that Infiniti could produce an engine with similar characteristics as that of the E46 M3. Then again, BMW did it with a 3.2 liter engine.
