Finally Dyno'd my Stock Bottom End Turbo M20

[ForcedFirebird]

Again SLEEPYDUB it's nice to know the number we saw here match yours for the most part. We saw 518@19psi on a Dynojet with a forged b25 (same camshaft), Rapidspool (aka Good & Tight ) manifold, same turbo. :D As I mentioned in the other thread, you didn't believe that you were over 500, we also thought it may be an anomaly hehe.

M20 FTW.

[SLEEPYDUB]

boost is also not logged in the dyno sheet so the real boost levels can be anything and the whp numbers real.

Boost and AFR are logged via MS3. I don't display that on my dyno. The 21psi was the average boost number once target was reached. The curve was very flat, with hardly any wavering.

[hasa]

boost is also not logged in the dyno sheet so the real boost levels can be anything and the whp numbers real.

[ForcedFirebird]

this is not a built 2.9L ported head, 288 cam, itb etc though, it is one of the 145whp jobs with a cam and e85

Mrlucretius engine would make basically the same numbers at sea level as its corrected by pressure, temp and humidity (the CF was around 1.2)

Yeah, I tend to babble.

The point was the numbers are not out of the realm based on stuff we built at work, and those basic engine calculations don't always hold true (but as you mentioned, it's close for TQ. Look how little the TQ changed with added boost, even though HP increased significantly.

If you look at the 2.7i (885 on an eta), they tend to do well with TQ. One jobber we did made 145whp, but 170wtq with that combo, when a typical m20 is close to square on HP:TQ.

[digger]

By the given base engine volumetric efficiency specs we can estimate the realistic power output on boost.

Let's be optimistic and say that the unported M20B27 with a cam like that has potential of 170whp as N/A. Then we multiply it with the boost pressure (13psi in the example)

170+(170*13/14.5) = 322whp

This is only true when there is optimal intake/exhaust pressure ratio. Too restrictive turbine sides may block the full potential.

The formula is easy and can be used to do simple math for reality checking.

That works much more reliably for torque, nevertless i agree torque seems high for the boost level (could be several reasons though) when compared to numbers below. It outdoes more than a couple of 3.2L when corrected to atmo and basically matches some on e85 with 500cc less

https://www.bimmerforums.com/forum/s...7#post26352417

As far as VE, I have built several b27's that make over 180whp NA. One of the members here has a 2.9l( mrlucretius ) - we remote dyno tuned it, 5000' elevation so it never saw past 75kpa in the logs. Still put down 215whp. Would love to see what it makes down here at sea level!

You can have over 100% VE and/or 100hp/liter. The s54 in stock form shows us that.

EDIT: To add to the confusion, dyno'd many eta engines with 885 heads slapped on them, they never made over 145whp. Tired m20b25's tend to do 145-155.

See here: https://www.r3vlimited.com/board/for...ad#post9875136

this is not a built 2.9L ported head, 288 cam, itb etc though, it is one of the 145whp jobs with a cam and e85

Mrlucretius engine would make basically the same numbers at sea level as its corrected by pressure, temp and humidity (the CF was around 1.2)

[ForcedFirebird]

with relatively lower power levels i.e. NA builds Dyncom are much happier than dynojet. Probably different with bigger power though

Local here made 518whp on same turbo and forged b25 at 19psi. Based on my experience, these numbers are not far off.

By the given base engine volumetric efficiency specs we can estimate the realistic power output on boost.

Let's be optimistic and say that the unported M20B27 with a cam like that has potential of 170whp as N/A. Then we multiply it with the boost pressure (13psi in the example)

170+(170*13/14.5) = 322whp

This is only true when there is optimal intake/exhaust pressure ratio. Too restrictive turbine sides may block the full potential.

The formula is easy and can be used to do simple math for reality checking.

Pressure is only half the equation. An hx35 turbo at 1bar is not going to make the same power as this Precision 6266 at 1bar. The flow ratios are far too different to stuff them in a generic formula. I have built many hx35 cars and they peak out at about 350whp on pump fuel at 15psi. As you can see above, the 6266 makes more at the same boost levels (~25% more).

As far as VE, I have built several b27's that make over 180whp NA. One of the members here has a 2.9l( mrlucretius ) - we remote dyno tuned it, 5000' elevation so it never saw past 75kpa in the logs. Still put down 215whp. Would love to see what it makes down here at sea level!

You can have over 100% VE and/or 100hp/liter. The s54 in stock form shows us that.

EDIT: To add to the confusion, dyno'd many eta engines with 885 heads slapped on them, they never made over 145whp. Tired m20b25's tend to do 145-155.

See here: https://www.r3vlimited.com/board/for...ad#post9875136

[hasa]

By the given base engine volumetric efficiency specs we can estimate the realistic power output on boost.

Let's be optimistic and say that the unported M20B27 with a cam like that has potential of 170whp as N/A. Then we multiply it with the boost pressure (13psi in the example)

170+(170*13/14.5) = 322whp

This is only true when there is optimal intake/exhaust pressure ratio. Too restrictive turbine sides may block the full potential.

The formula is easy and can be used to do simple math for reality checking.

[Northern]

225/45/16

Thanks. This gives me hope lol


and Re: Dynocom, there's a Dynocom awd dyno here and it's the local "heartbreaker" dyno as far as I'm aware.

[digger]

with relatively lower power levels i.e. NA builds Dyncom are much happier than dynojet. Probably different with bigger power though

[SLEEPYDUB]

What size are the R888R's?

225/45/16

clean setup. whats the size of your wheels and suspension?

16x9 and I run SLR angle kit up front, BC racing coils, and bunch of reinforcement and camber/toe correction in the rear

It does pretty well in roll racing or on slicks lol, so that's about what I expected. Putting your power to weight ratio into perspective; with a driver of a equivalent weight, it's about the same power to weight ratio as a typical 600cc supersport with rider. It would walk me on my lightly modded ZRX1200R from a wheelspin free roll.

Yea It walks 600s pretty hard. I'll be going M4 DCT here soon and we will see how it does from a dig

Dynocom.. LOL trump numbers. But surely nice car with engine like that!

I don't understand that reference, but maybe you are saying they are inflated? If so, you couldn't be more wrong, as this dyno reads lower then the other dynojets in town, but not quite as low as the Mustang 1750. This dyno has been consistently accurate with stock cars on their power outputs, so I am not quite sure what you are talking about.

[hasa]

Dynocom.. LOL trump numbers. But surely nice car with engine like that!

[varg]

It actually does pretty well. I don't do much dig racing, but if I do I use some 24.5" Mickey Thompson ET Drags. This is a drift car that does occasional roll racing. With these R888R out back, it has decent traction, enough to bust 600-700whp cars from a roll.

It does pretty well in roll racing or on slicks lol, so that's about what I expected. Putting your power to weight ratio into perspective; with a driver of a equivalent weight, it's about the same power to weight ratio as a typical 600cc supersport with rider. It would walk me on my lightly modded ZRX1200R from a wheelspin free roll.

[efficient]

clean setup. whats the size of your wheels and suspension?

[Northern]

What size are the R888R's?

[SLEEPYDUB]

Dumb question, what initiated the bam-bam-bam-bam-bam? I'm assuming it was spark cut, but why?

I have antilag setup on a momentary button. I use this for roll racing. It is spark cut. Builds enough boost to give me an edge on the start. 2.93 gears put me at one shift from 60-160.

Crazy. That is a lot of power for a ~2,500lb E30. I can't imagine it puts it all into forward motion.

It actually does pretty well. I don't do much dig racing, but if I do I use some 24.5" Mickey Thompson ET Drags. This is a drift car that does occasional roll racing. With these R888R out back, it has decent traction, enough to bust 600-700whp cars from a roll.

are you worried about running ethanol
through the stock lines/rail?

Not really. Haven't had pump gas in this car for nearly 4 years now. I did upgrade the soft lines to ethanol safe stock size lines, but the hard lines are all still stock.