Big Slice of Reality Pie., 2056 D-jet Dyno run Options

[Olympic 914]

Just got back from having the teener run on a Dyno.

Good and not as good as I expected.

Was hoping for at least 100 Hp, didn't make it.

This run was on a Mustang Dyno, allegedly a Dynojet Dyno reads from 12~15% higher.

First the good.

Runs were extremely consistent. the three runs printed pretty much right on top of each other.

Torque was way up there above 95 tq from 3000 to 4500. with no real dips.

HP numbers were very consistent with a nice smooth line from 2000 to over 4500

Now the bad

Max HP was only read at 88 Hp and max torque was 100.

If I add the 12-15% it comes to 100 Hp. But it is what it is.

Build is

2056 D-jet, Heads by HAM RS+, 8.6 comp. Raby 9590 cam, SS HEs with Triad muffler. I Have adjusted the MPS to what seems to run best for this car.

This car runs great and I just wanted to know what it was putting out, Not really planning to try to tune it for more power. Reliability is the key. and I am so far happy with that.

Dyno sheet added (Date/time is wrong, 5/06/21 8:35am)

[VaccaRabite]

Just keep in mind that is your HP at the wheels. Not at the crank. You loose a good bit through the 901 box ~15%.
That said you are detuned with that build. Somewhere something is not working as efficiently as it should. What are you using to control fuel? Carbs/DJet/EFI?
Zach

[Root_Werks]

There's still more power to be had with that build and D-Jet. Others will hopefully chime in. I thought there was something about modifying the MPS, bumping fuel pressure and even the CHT a bit to maximize HP/TQ.

[rfinegan]

That TQ looks great. I bet it drives and pulls great and can feel the difference in the upgrade.

Great Job

[Root_Werks]

That TQ looks great. I bet it drives and pulls great and can feel the difference in the upgrade.

Great Job

(IMG:style_emoticons/default/agree.gif)

Recalling the formula:

TQ = Acceleration
HP = Top Speed

Something like that. (IMG:style_emoticons/default/driving.gif)

[GregAmy]

That's really not hateful...did you do a "before"? Mine "before'd" last November at 75 ponies/96 torques on a Dynapack, and the torque was not near that flat. I need to get it to the dyno for the "after" on the FAT 2056 build.

What cam are you running?

[Jamie]

Just got back from having the teener run on a Dyno.

Good and not as good as I expected.

Was hoping for at least 100 Hp, didn't make it.

This run was on a Mustang Dyno, allegedly a Dynojet reads from 12~15% higher.

First the good.

Runs were extremely consistent. the three runs printed pretty much right on top of each other.

Torque was way up there above 95 tq from 3000 to 4500. with no real dips.

HP numbers were very consistent with a nice smooth line from 2000 to over 4500

Now the bad

Max HP was only read at 88 Hp and max torque was 100.

If I add the 12-15% it comes to 100 Hp. But it is what it is.

Build is

2056 D-jet, Heads by HAM RS+, 8.6 comp. Raby 9590 cam, SS HEs with Triad muffler. I Have adjusted the MPS to what seems to run best for this car.

This car runs great and I just wanted to know what it was putting out, Not really planning to try to tune it for more power. Reliability is the key. and I am so far happy with that.

Dyno sheet added (Date/time is wrong, 5/06/21 8:35am)

Forget what the charts show, it's the butt dyno feeling that counts! (IMG:style_emoticons/default/driving.gif)

[JamesM]

Were they monitoring your AFRs during the pulls?

Like others here I have to suspect accurate fueling may be an issue. Its pretty amazing how far off from ideal the mixture on these cars can be and still have them run decently.

PMB has been seeing dyno numbers over 100HP on stock 2.0L motors just from the conversion to modern EFI (utilizing stock d-jet intakes) I would expect you should be seeing at least that with your motor once properly dialed in.

[brant]

I was going to ask if there were any AFR charts also...

you might very well find extra HP with tuning of the MPS/mixtures...

we generally pick up 10hp when we dyno tune our carbs.

[Tom_T]

Changing to & properly tuning for the Euro 8.0 CR +/- 2L Heads got you a conservative Porsche 100 HP at 1971 cc (Porsche numbers were notoriously conservative then) - so I'd expect 110-115 or better from any 2056 build - Carb'd or Djet or other EFI (IIRC those were all at the crank - not rear wheels - so test "apples-for-apples").

Sounds like yours still needs some tweaking anyway.

For Greg - a buddy here in SoCal has a FAT 2056 with Djet that Ron built a number of years ago (don't ask me "what number") who was getting 120-125 HP at the rear wheels IIRC.

(IMG:style_emoticons/default/beerchug.gif)
Tom
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[GregAmy]

For Greg - a buddy here in SoCal has a FAT 2056 with Djet that Ron built a number of years ago (don't ask me "what number") who was getting 120-125 HP at the rear wheels IIRC.

Wow, that would be sweet. It feels really good with a nice flat torque curve. Very driveable. They installed their DJet cam though I'm running Microsquirt, and have a good VE table tuned to ~14.5 mid-throttle cruising and 12.8 for WOT.

It's all broken in now so I'll get around to the dyno soon enough. Maybe later this month or next.

Edit: here's my "before", w/ Microsquirt tuned close to the same AFRs. No history on the engine known.

[Olympic 914]

Were they monitoring your AFRs during the pulls?

Like others here I have to suspect accurate fueling may be an issue. Its pretty amazing how far off from ideal the mixture on these cars can be and still have them run decently.

Did not run a probe up the pipe, but the operator did monitor the AFR on my wide band AFR. He said it was in the md- high 11s at WOT.

So it looks like I could dial in the Full Load stop on the MPS a couple points.

Don't really know how much of a difference that would make though.

I am running single springs on the HAM RS+ heads, wonder if its starting to float the valves above 4500

Normal driving around AFR runs in the 12 ~ 14 range depending a lot on throttle position. I don't want to lean it out too much.

[rfinegan]

Not valve float @4500

[GregAmy]

...have a good VE table tuned to ~14.5 mid-throttle cruising and 12.8 for WOT.

Correction on that; those numbers are for the Toyota MR2 project. Below is he 914 AFR target table.

[Tom_T]

FYI by comparison for what you should be able to beat with your 2056 ....

The GA 2.0 USA stock 2.0L had better than your 88 max HP & 100 max TQ - with 116 lb/ft @ 3500 RPM & 95 HP @ 4900 RPM (DIN spec numbers) -

https://www.excellence-mag.com/resources/specs/367
.


FYI - Porsche USA stock numbers chart:


.... IIRC this is from the Porsche Chart(s) & made up by p914.com


1973 Owners Manual - with SAE 91 HP @ 4900 RPM, & 105 lb/ft @ 3500 RPM TQ numbers (ergo difference with Excellence's DIN numbers at the link above) -

.


IIRC SoCalAndy's (Andy T) prior yellow `72 914/4 with a twin 2-throat Carb (Weber?) 2056 cc turned out 125 HP, from what he told me - but that was +/- 7 years ago (prior to his current M471 yellow -6).

So maybe the current owner of that car &/or Andy T may know his old 2056's numbers, & whether it was crank or rear wheel.


Unfortunately I'm not finding my Euro Version performance chart for the their GB 2.0L with 100 HP & XXX TQ at RPM Curves - so maybe someone else who has it can post it. (IMG:style_emoticons/default/confused24.gif)


(IMG:style_emoticons/default/beerchug.gif)
Tom
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[GregAmy]

Don't forget that the standard for manufacturer dyno numbers changed in 1972. All the 2Ls prior to 1975 were rated at Gross (the old rating carried over), but Porsche had to go to the new Net rating for the '75 and '76 because of the re-rating for emissions. I believ there was also a compression ratio decrease?

For what we're doing today, Id' suggest stock ratings for the 2Ls should be compared to pre-75 numbers.

[Tom_T]

PS & slightly OT - of note on that p914 performance chart in my post above - people forget how well a stock 1970-72 1.7L performed vs. a stock 75-76 GC 2.0L as shown in the chart I posted above.

When I got my `73 "914S" 2.0 back in 1975 - I'd also test driven new 75 & 76 2L cars at dealers (100% financing on longer terms was about the same monthly payment as the used 80% with 20% down on my 3 year old car back then).

My "Butt Dyno" was definitely off with the later GC cars - and IIRC the California Cat Converter equipped 75-76 GC 2L cars were actually less HP due to the added smog tuning - down to only 78-80 HP, which they had to disclose with a loose specs sheet that they stuck into the dealer sales brochures (I have one somewhere in my deep-old storage boxes).

I'd also considered a few 71 7 72 1.7s back then, and I & my butt-dyno felt that they performed as good as or slightly better than the new 75-76 GC 2.0 cars, so I didn't see the extra cost as worth it, but the 73-74 2.0s were worth it - even back then.


From Dave Cheek's 1976 Owners Manual:

.


So folks with the 70-72 1.7s should really think about that before moaning about their 914/4's performance vs. late 2L cars - because they were in fact & butt-dyno felt about the same even when new for California's smog control burdened 914s, in part due to a bit less weight 70-72 without the BUBs & door impact bars, etc.

(IMG:style_emoticons/default/beerchug.gif)
Tom
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[Tom_T]

Don't forget that the standard for manufacturer dyno numbers changed in 1972. All the 2Ls prior to 1975 were rated at Gross (the old rating carried over), but Porsche had to go to the new Net rating for the '75 and '76 because of the re-rating for emissions. I believ there was also a compression ratio decrease?

For what we're doing today, Id' suggest stock ratings for the 2Ls should be compared to pre-75 numbers.

Greg - you're confusing the SAE & DIN gross to net spec switch for 1973 MY, with the 1975 MY GC 2.0L engine switch that was emissions control based. BTW - that gross to net switch was an auto industry wide change.

PS - the other emissions control cause spec shift for the USA was in the 1968 MY when they required the air injection into the exhaust manifolds to control emissions by "after-burning" in the manifold(s)/pipes

No - the change was for the 73 MY, which was why the 1.7L carryover (non-California cars) was slightly lower than 72 1.7L 914/4s - so my comments above about 70-72 1.7L vs 75-76 2.0L performance would also extend to 73 1.7 cars NOT from California with it's lower HP & TQ.

And NO - the 75-76 GC 2.0L is a completely different engine & performance in terms of their emissions control mandated detuning. That is the big difference that you're seeing for the 75 MY specs.

Also - since the change from Gross to Net & DIN to SAE specs was for the 1973 MY when the 2.0L flat-4 was introduced to replace the slow selling 70-72 914-6 - the Gross DIN & SAE specs for a 73-74 GA 2.0L motor is actually much closer to the prior 914-6's 110 HP (detuned from the 1969 911T's 120 HP for same motor), and the TQ would be better on the 73-74 GA 2L-4 motor, than for the -6 (it was already more torquey at lower rpm than the -6).

Granted that the 911 based 2.0L flat-6 has far more upside potential, as show by 64-69 911 models with up to 270 HP IIRC on street tuned versions - but the GA 2.0L /4's are far more streetable than the -6's, because you can get more torque pull at low rpm in 2nd & 3rd gear around town.

That was my butt-dyno impression on the 2 1970 914-6s that I test drove back in 1975 before getting my 73 2L - and neither of the -6's passed my factory 914 trained mechanic Hans' PPI anyway, so non-contenders for my & my budget back then a year out of college!

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Tom
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[SirAndy]

with 116 lb/ft @ 3500 RPM & 95 HP @ 4900 RPM (DIN spec numbers)

You say DIN and then proceed to show graphs with SAE ratings.
(IMG:style_emoticons/default/rolleyes.gif)

PS: 88/95 can get you into plenty of trouble. Plus, i take torque over HP any day.

[Olympic 914]

Well my Butt Dyno said this engine had more than 100+ Hp.

I guess it was just the Torque talking (IMG:style_emoticons/default/lol-2.gif)