ForcedFirebird's m20 dyno thread.

[mikey.antonakakis]

Dyno software makes normally barometric compensation to sea level pressure. 211whp sounds quite reasonable for a B29 peaking @6000rpm on sea level.

Ah, I’ve been wondering about that… philosophically I don’t know how I feel about that, especially for a turbo car. Implying that a turbo car that makes an actual 500whp in Colorado would be fine making 600whp at sea level does not seem realistic. I’ll give the SAE a call and voice my complaints! Lol

[hasa]

Very nice results on the Denver car! Yep, 80kPa baro is what I see here (now running the MAP Daddy sensor with the additional baro sensor). N/A up here *should* be about 20% less power as a result, although I’ve wondered if you can go more aggressive on timing and get some of that power back? Or are you hitting MBT before knock with a build like that?

Anyway, that 211whp at 80kPa baro should be something like 264whp at sea level… I bet that engine would do good with some boost, I’d love to get more details on the setup if you can share!

Dyno software makes normally barometric compensation to sea level pressure. 211whp sounds quite reasonable for a B29 peaking @6000rpm on sea level.

[mikey.antonakakis]

Very nice results on the Denver car! Yep, 80kPa baro is what I see here (now running the MAP Daddy sensor with the additional baro sensor). N/A up here *should* be about 20% less power as a result, although I’ve wondered if you can go more aggressive on timing and get some of that power back? Or are you hitting MBT before knock with a build like that?

Anyway, that 211whp at 80kPa baro should be something like 264whp at sea level… I bet that engine would do good with some boost, I’d love to get more details on the setup if you can share!

[ForcedFirebird]

Higher CR gives us a low end lift.

But, but, but, you are "supposed" to have 8.5:1! lol

Hogwash. The more power your engine makes NA, will only be amplified by a turbo. Your tuning window just gets narrower as the static CR goes up. This is why 80's turbo Dodge, or even the Grand National had 7.5-8:1 SCR. My second turbo build I ever did was 9.4:1. My twin turbo Firebird was 8.8, just like the stock m20. My user name is based on that "Forced (induction) Firebird".

[ForcedFirebird]

m20b29 I tuned in a "mile high city" Denver, from here in Florida. After the first two pulls, I read the logs and wondered why they didn't open the throttle all the way (80kpa max), then realized that a mile in the air, you have ~20% less pressure lol. This was before and after tune:

[ForcedFirebird]

It's amazing that both graphs are basically identical upto 5000rpm.

So the first has
- standalone ecu
- header
- exrtrude hone
- bbtb and fine style inlet
- tighter squish clearance

But the second has a IE 272, is it regrind or Schrick knock off ?

Reading back, I have a gut feeling the breathing mods helped over 5k RPM. Recently had a customer purchase a Spec e30 legal engine. Rules only allow standard rebuild procedures, max .5mm over stock pistons. He put a megasquirt on it, with headers, and decent exhaust. I wasn't there, but Active Auto in Miami dyno tuned it, and it made 179whp peak.

272 cam was new from IE.

I am sad, it's been at least a year since I have personally dyno'd an m20. Have done a few remote tunes, perhaps I should see if I still have the graphs.Last few trips to the local rollers has been an s50, s52, both e36's, and a formula Sport Racer with a 13b rotary.

[dvallis]

Here's a new dyno plot for the thread. M20B28 turbo, 10:1 CR JE pistons, wasted spark, Garrett GT3076R ball bearing oil/water 0.63 turbo

Higher CR gives us a low end lift. Garrett gets to full boost 500 RPM sooner than the original PTE. Might upgrade to E85 so we can add more high end timing and lift the torque curve above 5000 RPM.

[ForcedFirebird]

My ex Bosch FLA 203 dyno was reading 211whp / 249bhp for a M20B29 @7000rpm.

That sounds about spot on with a dynojet. I have been seeing in the 210-220 pretty consistent with stroker builds.

[hasa]

That was just a random video I saw in a car sales ad. Not mine absolutely. But from my point of view as E30 owner it looked performing very well.

When the tire pressures, roller friction and tie straps are done ok the measurement of driveline losses work ok. But to be honest there are horrible anecdotal examples where the losses are all over the place.

My ex Bosch FLA 203 dyno was reading 211whp / 249bhp for a M20B29 @7000rpm.

[ForcedFirebird]

anymore details? to be fair 310bhp on a European dyno is like 200whp everywhere else (excluding dynocom or land and sea/dynomite)

If there were at least some kind of consistency, BHP calcs could work, but a t56 robs a lot more power then a g260 - calculating backward never works. At least this thread is primarily Dynojet, which I have personally found extremely consistent. The race organizations here often will bring a Dynojet out to the track to catch any cheaters in the HP/WT classes - they are usually within 1-2% of the Dyno we have here by the shop.

[ForcedFirebird]

https://www.youtube.com/watch?v=W5FE21I2hRA

310bhp N/A M20B29 on the video. Probably 400whp on a Dynocom scale ...lol.

Is that you driving?

e30 with m20b25 vs a pack of RX7 & 8's at the SCCA national runoffs (championships). Easier to see speed when there's other cars on the track. How much HP does this one have? ;)

https://www.youtube.com/watch?v=kDQjQPWKUpw&t=310s

[digger]

https://www.youtube.com/watch?v=W5FE21I2hRA

310bhp N/A M20B29 on the video. Probably 400whp on a Dynocom scale ...lol.

anymore details? to be fair 310bhp on a European dyno is like 200whp everywhere else (excluding dynocom or land and sea/dynomite)

[hasa]

https://www.youtube.com/watch?v=W5FE21I2hRA

310bhp N/A M20B29 on the video. Probably 400whp on a Dynocom scale ...lol.

[dvallis]

Updating the thread with new turbine numbers

Original: Precision Turbo T4 6262 0.7 A/R compressor, 62 mm inducer, 82 mm exducer, 0.84 A/R turbine, 2.5" inlet, 4" outlet



Updated: Same as above, changing turbine to 0.58 A/R

19 PSI


10 PSI

[SLEEPYDUB]

^^^we had discussed you power a long time ago on this forum. Local made 518 @ 19psi, same turbo, but straight b25, same cam too - glad to see it's verified. One of the plots that aren't to be made public. :(

Yea i was skeptical about that when you mentioned it! I am glad to see that its possible, and boy look at that curve, looks great for a single cam!