Little video of my ej9 d14Z2
http://www.youtube.com/watch?v=d2i4CO1ZTUE
ej9 john dyno test
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saxophonias
- Posts: 2592
- Joined: Fri Jul 03, 2009 6:03 am
Re: ej9 john dyno test
it pulls extremely well! Bravo!
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Dodo Bizar
- Site Admin
- Posts: 2009
- Joined: Mon Jun 22, 2009 10:36 pm
Re: ej9 john dyno test
I still have some dyno charts and a story to tell in the dyno meet workshop topic, but I wanted to add a little side note here in this topic, just for thought food.
Lately I have been involved in a 3.0 liter V6 engine race car project. It's completely not Honda related, it's Alfa Romeo. But physics stay physic, no matter the brand. The typical V6 stock units deliver between 220 bhp and 270 bhp I believe depending on specs. Now this car is tested and maintained by the same shop I did all my Civic D14 measurements, the 116 bhp non-Vtec, the 130+ VTEC and the 145 bhp Skunk2 cam measurement. So same dyno, same methods, race prepped engine which in 3.2 liter shape (different crank) produced between 300 and 330 bhp in the past. Custom intake, custom headers, custom exhaust and tuned using KMS (Kronenburg).
Now for this year some race spec cams where placed and the setup was made into 3.0 liter (regulations thing, so we could loose some weight)... high hopes on the dyno... what happened, barely 290 bhp and very peaky, so narrow power band... bottomline in my believe is the customs headers, they were so -called racing headers made somewhere in the USA... but the dimensioning is crap. Runners where unequal and lengths too short. (See Bisimoto, loooong runners are needed for high performance, or an optimal length which I believe is about 40 cm for this car while the longest right now is just 28 cm). Unfortunately having long runners and the chassis used don't match, some very creative thinking (or cutting and welding) is needed. But still the target with these cams is around 350+ range. Not coming anywhere near I got involved and found these findings .... but it makes me realize how important things like proper runner lengths can be and in hindsight, might have affected the D14 Civics (tested on the same dyno) that could not get 110 bhp just like this topics cars.
I am just recently realising how lucky I have been with some of my initial setup choices with my D14 projects and how easy it is to fail seeing the difference.
About changing the intake manifold for instance, I for long believed it was a matter of resistance, but I think the diff between D15B7 and D16Z6 is close to none... though D16Z6 has much wider runners. The difference might still come however from the average velocity. In a D15B7 manifold, with the same filling of cylinders, the average velocity in a runner is higher, therefore a pulse wave travelling trough it takes much longer to reach the plenum. Yes the reversed pulse travels faster towards the cylinder back, but the sum of both travelling times is different (longer when average mass velocity is higher), the D15B7 pulse takes longer and therefore MIGHT optimize power/torque on a lower rpm. How different parts actually mix and match I don't know. I just started head first by trying it in 2005 and only recently I have toyed around with the tools that could compute it (at least in a relative manner).
Motoman articles (see elsewhere) are very interesting in this manner. He can get more power sometimes by narrowing down the throat in the inlet ports, this in my opinion creates a local high velocity, resulting in a similar pulse return time elongation as discussed above in the D15B7/D16Z6 manifold case. A longer pulse return time could also be achieved by having a longer inlet runner, but that directly leads to more resistance and worse loading. Perhaps his small throat has the benefit of keeping a shorter runner length while getting a different pulse tune time.
A well, John, I hope you do not completely loose me in my rambling. Bottom line is that there are sometimes these completely missed interactions which I have not recognized myself for years. My story flips from exhaust to inlet discussion, but basic pulse principles are the same for both, though exhaust is way more complicated to compute correctly. In your cases the inlet traject is clear, but for the 4-2-1 exhaust manifold, I am curious what the length of the primary runners was... there a 10 cm difference between mine and yours might give us a clue...
Lately I have been involved in a 3.0 liter V6 engine race car project. It's completely not Honda related, it's Alfa Romeo. But physics stay physic, no matter the brand. The typical V6 stock units deliver between 220 bhp and 270 bhp I believe depending on specs. Now this car is tested and maintained by the same shop I did all my Civic D14 measurements, the 116 bhp non-Vtec, the 130+ VTEC and the 145 bhp Skunk2 cam measurement. So same dyno, same methods, race prepped engine which in 3.2 liter shape (different crank) produced between 300 and 330 bhp in the past. Custom intake, custom headers, custom exhaust and tuned using KMS (Kronenburg).
Now for this year some race spec cams where placed and the setup was made into 3.0 liter (regulations thing, so we could loose some weight)... high hopes on the dyno... what happened, barely 290 bhp and very peaky, so narrow power band... bottomline in my believe is the customs headers, they were so -called racing headers made somewhere in the USA... but the dimensioning is crap. Runners where unequal and lengths too short. (See Bisimoto, loooong runners are needed for high performance, or an optimal length which I believe is about 40 cm for this car while the longest right now is just 28 cm). Unfortunately having long runners and the chassis used don't match, some very creative thinking (or cutting and welding) is needed. But still the target with these cams is around 350+ range. Not coming anywhere near I got involved and found these findings .... but it makes me realize how important things like proper runner lengths can be and in hindsight, might have affected the D14 Civics (tested on the same dyno) that could not get 110 bhp just like this topics cars.
I am just recently realising how lucky I have been with some of my initial setup choices with my D14 projects and how easy it is to fail seeing the difference.
About changing the intake manifold for instance, I for long believed it was a matter of resistance, but I think the diff between D15B7 and D16Z6 is close to none... though D16Z6 has much wider runners. The difference might still come however from the average velocity. In a D15B7 manifold, with the same filling of cylinders, the average velocity in a runner is higher, therefore a pulse wave travelling trough it takes much longer to reach the plenum. Yes the reversed pulse travels faster towards the cylinder back, but the sum of both travelling times is different (longer when average mass velocity is higher), the D15B7 pulse takes longer and therefore MIGHT optimize power/torque on a lower rpm. How different parts actually mix and match I don't know. I just started head first by trying it in 2005 and only recently I have toyed around with the tools that could compute it (at least in a relative manner).
Motoman articles (see elsewhere) are very interesting in this manner. He can get more power sometimes by narrowing down the throat in the inlet ports, this in my opinion creates a local high velocity, resulting in a similar pulse return time elongation as discussed above in the D15B7/D16Z6 manifold case. A longer pulse return time could also be achieved by having a longer inlet runner, but that directly leads to more resistance and worse loading. Perhaps his small throat has the benefit of keeping a shorter runner length while getting a different pulse tune time.
A well, John, I hope you do not completely loose me in my rambling. Bottom line is that there are sometimes these completely missed interactions which I have not recognized myself for years. My story flips from exhaust to inlet discussion, but basic pulse principles are the same for both, though exhaust is way more complicated to compute correctly. In your cases the inlet traject is clear, but for the 4-2-1 exhaust manifold, I am curious what the length of the primary runners was... there a 10 cm difference between mine and yours might give us a clue...