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My car sneezes
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Discussion Starter #1
these are the numbers I put down,
blue=first pull
green=second pull
yellow=third pull, not sure what happened here though


lol. Sorry, here's the real post.

Since I was tired of the car not being able to hold more than 13.5psi at redline, I decided to have the turbos reflowed. For refrence here's the previous dyno with boost spiking to 17psi falling off to 13psi:


Now for the new graph. Notice how flat the tq curve is now and I only lost 200rpm of spool time. Blue is 12psi, red is 15psi, and green is 16psi.


This was on a conservative dyno known to read about 5% lower than most. Overall, I'm happy with the car. It's making more power with less peak boost but it's holding boost now. It also seems Johan's ECU runs very rich on hot air but with lower charge temps and adjusting the water injection, the a/f ratio fell right in place in the mid to high 11's. Even at 16psi the car stays cool; cooler than before at 12psi and no water injection!!!!

Here's the vid. The red car is Alan's (E5PR1T) running only 11psi of boost and water injection.

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Some very nice hp numbers, but you did lose torque. Is the hp making it up in feel? Well guess its not to much torque, still all around great #'s.
 

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My car sneezes
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656 Posts
Discussion Starter #4
Thanks Ron!!!

Some very nice hp numbers, but you did lose torque. Is the hp making it up in feel? Well guess its not to much torque, still all around great #'s.
I lost tq because I'm running less peak boost although you really cant feel the lower tq but you can feel the higher hp; it just pulls and pulls and pulls!!! :evil:
 

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Very impressive. What ECU are you running?
 

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Very nice. I dont know much about the esprit's. What do they dyno to the wheels stock? Good job though:D
 

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My car sneezes
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656 Posts
Discussion Starter #8
Very nice. I dont know much about the esprit's. What do they dyno to the wheels stock? Good job though:D
Thanks. Stock they dyno about 300 to 340 to the wheels depending on year.
 

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Wonder if you are being misled, though.
There is a math relationship between HP and Torque that cannot be violated.
Basically:
Power (in HP) = (Torque (ft-lbs) x engine speed (rpm))/5252.
That is why the HP vs Torque curves must cross at 5252 rpm, and it is also why Torque generally cannot remain constant as HP increases beyond that rpm.
 

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My car sneezes
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656 Posts
Discussion Starter #11 (Edited)
Thanks Lotustt

Wonder if you are being misled, though.
There is a math relationship between HP and Torque that cannot be violated.
Basically:
Power (in HP) = (Torque (ft-lbs) x engine speed (rpm))/5252.
That is why the HP vs Torque curves must cross at 5252 rpm, and it is also why Torque generally cannot remain constant as HP increases beyond that rpm.
How I'm I being misled? While I do agree hp is a product of tq using the formula, tq falling off has nothing to do with the formula and all to do with the efficiency of the engine. Look at a mid-80's Chevy Crossfire, tq will fall off WAY before 5252. Then look at an S2000, peak tq happens way after 5252.
 

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Gonzo asked:
How I'm I being misled?
Gonzo you may or may not be being misled. but the only way you are being mislead is if the dyno is not properly calibrated or the conditions are not corrected to standard day correctly. At the end of the day, your assumption is correct. :clap:

LotusTT said:
There is a math relationship between HP and Torque that cannot be violated.
Basically:
Power (in HP) = (Torque (ft-lbs) x engine speed (rpm))/5252.
LotusTT you are correct in that statement.

However, your logic runs astray afterward:
That is why the HP vs Torque curves must cross at 5252 rpm, and it is also why Torque generally cannot remain constant as HP increases beyond that rpm
It works like this:
1) The dynamometer measures torque.
2) The Hp value is calculated using your aforementioned formula.

Regards,
Ron
 
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