dyno'd the 2.7i

[digger]

why do you UK blokes always use reverse calculated flywheel figures? so the power figures can be inflated any way you like? :p

22% drivetrain loss on an E30 is 100% imaginary. Most of those power figures are sad (especially given the mods), there are stock M20B25s here that make more power with everything 100% stock.

example:

http://www.r3vlimited.com/board/member.php?u=13411

there was also a guy with a 200,000+ mile, stock B25, with just a dinan chip, that had both a better powerband and better peak power than any of those motors.

Dyno dynamics is just a constant factor of 20% and you are comparing to a dynojet i pressume which almost always read higher.

[nando]

even if it reads significantly higher, at best he's making the same HP as a stock M20B25 with all those mods.

and reverse calculated crank figures are still baloney.

[briansjacobs]

I think the important that people forget is that it is very easy to bolt on less power. If you have not done before and after dyno pulls please do not bother to respond, Nando and I, and Brody have all been there, seen it and done it. As a matter of fact Brody is the one I have seen post that his part made less power than stock until retuned, and then and only then was it a signifacant increase. Kudos to Brody for speaking the truth and not just selling his wares like so many others.

[ForcedFirebird]

not showing any numbers on purpose, I just wanted to show the sexy curves we are making. on later runs we got the AFR flat and numbers got a little better but I never printed that sheet out. For the most part I dont have a need to rev past 6k because the torque is more usefull than the HP

Nice curves, Brian, what are you 36-24-36? hehe

I think the important that people forget is that it is very easy to bolt on less power. If you have not done before and after dyno pulls please do not bother to respond, Nando and I, and Brody have all been there, seen it and done it. As a matter of fact Brody is the one I have seen post that his part made less power than stock until retuned, and then and only then was it a signifacant increase. Kudos to Brody for speaking the truth and not just selling his wares like so many others.

Almost always power is decreased without a tune. Headers generally make an engine run lean, increase in compression or displacement will make it run lean, etc etc.

I have been around dynos :P and know the importance of tuning. I have owned the tuning equipment for years now, but since we mostly work on GM cars, we had no reason to get an emulator since the stock GM ECM has a data-feed. Just yesterday, purchased an emulator and a few other things for the BMW (even some header tubing w00t!). Plan is to get the fueling decent on the street, then tune the spark advance on the next dyno session. Then headers, re-tune and another dyno.

People don't realize the importance of tuning. We have seen as much as 30hp increases on an otherwise stock motor after a tune, generally OEM stuff will err on the side of rich to give the bearings a little extra life - you ever seen a consistently lean engine after break-down? The bearings look like a teenage kid with acne problem, pistons will often have stress marks and/or chips out of them...then you have the other side, when consistently rich will have glazed cylinder walls, severe build up on the tops of the pistons among a few other things. Just because an engine is NA doesn't mean fueling and timing are any less important, and not just an issue with power, but longevity as well.

[eta]

I can only go with the figures posted by people. I wish everyone would post wheel figures, Nando, they don't however. As I have wheel figures for my car I simply worked out the drive train loss from mine (28%) and applied that to the other dyno plots. The 35 hp drive train loss I "see" is "apparantly" what other dyno's here show and with conversions with a physist/engineer this figure is not too unrealsitic apparantly. Given the loss used is high I do not believe I am over reporting the numbers that I suggest. I know originally I posted a 22% drivetrain loss, that was simpley a typing error, now corrected. The reversed calculated figures where done based on a 28% drive train loss though so those are right, I double checked.

Please don't flame me Nando for trying to provide some evidence in my posts, you just assumed I plucked numbers out of thin air without asking me where I got them from.

I agree with the tuning bit though. Mine runs too rich but will be tuned soon. The plan is to ditch the AFM and tune it using a MAP sensor. It's an experiment that should work. Then like Forced firebird a new exhaust will be fitted and a retune will follow.

[nando]

I can only go with the figures posted by people. I wish everyone would post wheel figures, Nando, they don't however. As I have wheel figures for my car I simply worked out the drive train loss from mine (28%) and applied that to the other dyno plots. The 35 hp drive train loss I "see" is "apparantly" what other dyno's here show and with conversions with a physist/engineer this figure is not too unrealsitic apparantly. Given the loss used is high I do not believe I am over reporting the numbers that I suggest. I know originally I posted a 22% drivetrain loss, that was simpley a typing error, now corrected. The reversed calculated figures where done based on a 28% drive train loss though so those are right, I double checked.

Please don't flame me Nando for trying to provide some evidence in my posts, you just assumed I plucked numbers out of thin air without asking me where I got them from.

I agree with the tuning bit though. Mine runs too rich but will be tuned soon. The plan is to ditch the AFM and tune it using a MAP sensor. It's an experiment that should work. Then like Forced firebird a new exhaust will be fitted and a retune will follow.

not flaming, just pointing out that the flywheel calculated figures are way optimistic. 28% is even worse. The real loss is probably somewhere between 15-20%.

think about it thermodynamically. if 28% of your power is being "lost" to the drivetrain, most of that is being converted to heat energy. if you make 200hp, that's 56hp being converted to heat. You'd melt something in a hurry. It's also not linear, IE you don't lose 28% or whatever magic # at 500hp the same as you do at 100hp. It may well be 28% at stock eta power levels though, 121 flywheel isn't much to start with.

I appreciate the sharing and I'm glad there are others willing to modify an old motor. I don't get very excited over vanilla plastic covered M50s..

[ForcedFirebird]

I don't get very excited over vanilla plastic covered M50s..

Awesome quote lol. I feel the same way about my v6's (specially turbo) in my f-bodies :D

[briansjacobs]

I can only go with the figures posted by people. I wish everyone would post wheel figures, .

did you notice on mine I posted no numbers and only showed the curve? numbers are bull shit unless you are using the exact same dyno (not same kind using same software version) on the exact day at close to the same time. I have done the same car on different days on the same dyno and got different readings.

[ieatpeople]

I should dyno my poor old POS.

Everyone thinks it is a badass because it sounds so mean...but it is a 320,000 mile bone stock M20 (well, AFAIK) with an ebay exhaust that was loud when it was new and is about 300X worse now.

I bet I get nowhere near 134 HP, and it runs OK.

my poor old pos dynoed pretty good (88 528e, k&n drop in, aftermarket muffler, no cat), she put down 124hp/151tq at 210k miles.

so the i head swap just gives a little more hp and alot more tq.
sweet, i love torque.

[ForcedFirebird]

did you notice on mine I posted no numbers and only showed the curve? numbers are bull shit unless you are using the exact same dyno (not same kind using same software version) on the exact day at close to the same time. I have done the same car on different days on the same dyno and got different readings.

another QFT, Brian!

Man, we need to meet up sometime :p

I have flowed the same heads on my same flow bench with and without re-calibration in the same day and came up with slightly different results, but the jist is the numbers are close enough for comparison results, this is why I always use % gain over stock as comparison for my racing heads. Competitors show that the stock heads flow generally (stock for stock) more than my bench says, but somehow the heads leaving here equal or better theirs even with my "low numbers (yes I am still at my shop 8:30 at night, prolly be here till 12-1am, and have to go to my 7am construction job in the morn)...

[briansjacobs]

Nice curves, Brian, what are you 36-24-36? hehe

36-24-36? only is she is 5'3"

[briansjacobs]

another QFT, Brian!

Man, we need to meet up sometime :p

I have flowed the same heads on my same flow bench with and without re-calibration in the same day and came up with slightly different results, but the jist is the numbers are close enough for comparison results, this is why I always use % gain over stock as comparison for my racing heads. Competitors show that the stock heads flow generally (stock for stock) more than my bench says, but somehow the heads leaving here equal or better theirs even with my "low numbers (yes I am still at my shop 8:30 at night, prolly be here till 12-1am, and have to go to my 7am construction job in the morn)...

I have run the same car on two different dynos and showed 180hp on one and 165 on the other. I can see 15 hp difference at 500, but at less than 200 I just dont care anymore. All I look for at this point is AFR, how much more power can I make and still be safe?

I have a wide band at the collector that plugs in directly to the dyno, no sniffer tube for me. I found the difference to be 11.9 with the wide band vs 12.4 with the probe at WOT, still safe but not optimal.

[briansjacobs]

another QFT, Brian!

Man, we need to meet up sometime :p

.

yes we do, the past few months my youngest has been awful and is wearing us both out. As soon as she stops being a bitch I will go out at nights again. Yes I just called my 9 month old a bitch!

[ForcedFirebird]

yes we do, the past few months my youngest has been awful and is wearing us both out. As soon as she stops being a bitch I will go out at nights again. Yes I just called my 9 month old a bitch!

We have 4 kids, know the routine ;) Oldest is 12, youngest is 4.

[eta]

The problem with quoting 15-20% drive train loss Nando is that I have yet to see an engine installed on a engine dyno and the power/torque curve that results and the same engine installed in a car and the wheel figures that are then produced. Until I see that, the 15-20% figures that I see quoted in many places, seem like recieved wisdom to me. Also the ammount of heat that comes from the transmission in my car, is conciderable, so a high transmission loss is plausible (although maybe not 28%). At first I did not believe that such a loss is plausible but after conversation with a physist who does alot of engine modelling that drive train losses approching that could be possible for E28/E30's. However the exact figure remains unknown, unitl then I will stick the 28% figure indiacted by my RR day.

Also the the estimated flywheel figures are just that estimated. The wheel figures are real. I know this because being a little sad I have created a spreadsheet that uses the wheel curve that I have to determine acceleration in any gear against time. The spreadsheet actually starts at a given speed therefore a given rpm depending on the gear ratio selected. Thus knowing the wheel power, acceleration can be determined and therefore the time taken to the next time point, 0.1 secs later and the new speed. The iterative process continues for as long as I can be bothered to copy and paste. Air resistance and rolling resistance is factored in.

As I have the wheel figures for my car and gear ratio details, I can predict 30-70 time in 3rd and 50-70mph time in 4th. They are exactly what I observe on road testing. So The wheel figures I have posted for my car are real @125whp, not alot I grant you but the same as the eta produced at the flyhweel when it was new. Given I have the stock eta exhaust system and the other E30 based conversions I posted are running custom exhaust setups I don't think the wheel power figures I have given (for the first two plots Dalimerman and the second one) are too high at 135-140 whp. What the actual drive train loss is, is of no concern to me as its the wheel figures that matter, hence the reverse calculation for some of the plots.

Physics does not lie. I do try to have a basis for the numbers I post and although some of them are estimates, I think they are real.