FI Dyno thread

[jflogerzi]

Originally Posted by BrahmaBull1990

Damn this sounds soooo good

Leave this as well. I do miss the sound

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[BrahmaBull1990]

Originally Posted by jflogerzi

Leave this as well. I do miss the sound

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Sooo good! How did the 245s hold the power? NA my car felt heavy in first when just street driving. I’m curious how boost changes that.

[jflogerzi]

Originally Posted by BrahmaBull1990

Sooo good! How did the 245s hold the power? NA my car felt heavy in first when just street driving. I’m curious how boost changes that.

Street was just fine. Track was different and autocross as well. Had to be careful not to get on throttle to soon or it wanted to kick the backend out. Boosted on the street was so much fun due to bell curve TQ output.

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[BrahmaBull1990]

Here is the dyno from my Edelbrock SC I just had installed. I noticed my toque comes on around 3k and hits 220ft/lbs. Is that too much for stock rods? I see most people say to stay around 200ft/lbs, from what I’ve been reading historically (all hearsay, of course).

Should I ask my tuner to lower the torque, if possible? I drive pretty conservatively; no track or auto-x

[jflogerzi]

That Dyno plot is perfect. Flat and ramps in nicely. Nothing is 100% safe but you are in the safer region.

Couple things. With boost you need to change your driving habits a bit. Don't floor it while lugging the engine. Also warmup is important now. Stay out of boost till oil temps get to a safe area. Other than this enjoy and have fun. For a while keep an eye on afr while driving. Highly recommend a p3 vent gauge that plugs into obd2 port.

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[BrahmaBull1990]

Originally Posted by jflogerzi

That Dyno plot is perfect. Flat and ramps in nicely. Nothing is 100% safe but you are in the safer region.

Couple things. With boost you need to change your driving habits a bit. Don't floor it while lugging the engine. Also warmup is important now. Stay out of boost till oil temps get to a safe area. Other than this enjoy and have fun. For a while keep an eye on afr while driving. Highly recommend a p3 vent gauge that plugs into obd2 port.

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Awesome advice - thank you! Currently I wait about two minutes after cold start RPMs drop to start driving and do not go-over 1/2 throttle or 4k rpm before oil hits at least 180*.

When driving, I roll onto the throttle and do not go-over half throttle until at least 3k RPM (never over half throttle in 6th; rarely in 5th). My shift are also 6k max since this when I hit peak HP, and only on occasional pulls.

Thanks for the tip about the p3 vent -- I have been using my bluetooth ecutek device plugged into the OBII and have it on in my cell cradle.

[86TOYO2k17]

Originally Posted by BrahmaBull1990

Awesome advice - thank you! Currently I wait about two minutes after cold start RPMs drop to start driving and do not go-over 1/2 throttle or 4k rpm before oil hits at least 180*.

When driving, I roll onto the throttle and do not go-over half throttle until at least 3k RPM (never over half throttle in 6th; rarely in 5th). My shift are also 6k max since this when I hit peak HP, and only on occasional pulls.

Thanks for the tip about the p3 vent -- I have been using my bluetooth ecutek device plugged into the OBII and have it on in my cell cradle.

idling too long can actually cause more harm then good. You have less oil pressure, typically a richer less clean burn with more fuel contamination into the oil, and you extend the total overall warmup time. waiting about 30seconds or just after initial higher rpm idle drop which of the two takes longer is plenty, perhaps in freezing temps another 20-30seconds but otherwise no point.

You should be shifting just before limiter for maximum acceleration, 6k is far from when you should be shifting. Peak hp is meaningless. You shift when mechanical torque at the wheel in the current gear is less than mechanical torque at the wheel would be in the next gear you would be shifting to, typically this rpm however is beyond even the limiter so we are limited to the rpm of the limiter before shifting.

[BrahmaBull1990]

Originally Posted by 86TOYO2k17

idling too long can actually cause more harm then good. You have less oil pressure, typically a richer less clean burn with more fuel contamination into the oil, and you extend the total overall warmup time. waiting about 30seconds or just after initial higher rpm idle drop which of the two takes longer is plenty, perhaps in freezing temps another 20-30seconds but otherwise no point.

You should be shifting just before limiter for maximum acceleration, 6k is far from when you should be shifting. Peak hp is meaningless. You shift when mechanical torque at the wheel in the current gear is less than mechanical torque at the wheel would be in the next gear you would be shifting to, typically this rpm however is beyond even the limiter so we are limited to the rpm of the limiter before shifting.

Thanks for the reply. Sorry I am confused. You're saying I should be shifting at around 7k RPM (assuming redline is around 7.2kRPM)? My torque and HP are highest right at 6k RPM; if this is the max in the current gear, how could the torque be higher in the next when I am upshifting?

[jflogerzi]

Originally Posted by BrahmaBull1990

Thanks for the reply. Sorry I am confused. You're saying I should be shifting at around 7k RPM (assuming redline is around 7.2kRPM)? My torque and HP are highest right at 6k RPM; if this is the max in the current gear, how could the torque be higher in the next when I am upshifting?

RPMs fall when shifting into next gear. This if you shift early you are father from the sweet spot for your torque and HP curve.

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[BrahmaBull1990]

Originally Posted by jflogerzi

RPMs fall when shifting into next gear. This if you shift early you are father from the sweet spot for your torque and HP curve.

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Ahhh understood. So wringing it out to 7k vs 6k isn’t adding more wear? Keep in mind this during a pull. City driving I’m a piker around 4.5k

[jflogerzi]

Originally Posted by BrahmaBull1990

Ahhh understood. So wringing it out to 7k vs 6k isn’t adding more wear? Keep in mind this during a pull. City driving I’m a piker around 4.5k

Nope not really. FI is adding accelerated wear vs NA at any level but you knew that.

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[Decep]

These engines always feel kind of sketchy to me past 6500 rpm. I'm sure it's fine but that's about where i push mine. Just sounds so strained after that.

[86TOYO2k17]

Originally Posted by BrahmaBull1990

Thanks for the reply. Sorry I am confused. You're saying I should be shifting at around 7k RPM (assuming redline is around 7.2kRPM)? My torque and HP are highest right at 6k RPM; if this is the max in the current gear, how could the torque be higher in the next when I am upshifting?

Stock limiter is 7,400 most tuners raise to 7,500.
Shift 50rpm before limiter. Shift at the last possible moment to still not hit limiter/fuel cut but rev as high as possible.

I specified mechanical torque to the wheel.
Not torque or hp on a dyno graph.

Mechanical torque is calculated after all gear ratio, wheel size etc… are factored in.

You want to shift gears at the RPM when the current gear you are in has LESS mechanical torque at the wheel than the next gear will have at the RPM it will land in after shifting.

On most cars the mechanical torque to the wheel is always higher in the numerically lower gear all the way to rev limiter. You’d need to make like 400ft lbs at 5k and 200ft lbs at 6,500rpm to benefit from short shifting. A 20-30% drop in torque is more than made up for by torque multiplication through numerically higher gearing.

[86TOYO2k17]

Originally Posted by BrahmaBull1990

Ahhh understood. So wringing it out to 7k vs 6k isn’t adding more wear? Keep in mind this during a pull. City driving I’m a piker around 4.5k

Lugging, overall temps, and overall power are substantially a much bugger factor than revving to factory limiter. As long as you don’t have oil starvation, valve float, or lifting a head which you most likely are not then shifting at 6,300 vs 7,300 wont make much difference. Your actually making less engine torque at the higher rpm anyways. Let her rev out she wants it. Just don’t bang limiter.