Honda / Acura K20a K24a Engine Forum banner
921 - 940 of 943 Posts

·
Registered
96 civic HX K24a
Joined
·
2,022 Posts
Thanks @Lotus for your experience on the driveshaft side. We will work out a solution like I proposed above with conventional machine elements. Of course we use approaches to reduce the notched impact effect.

This Saturday we will mount driveshaft and exhaust back, connect the harness and plug the ECU, fill up all liquides and run the engine to see how far we are from dyno ready. I've talked to an owner of a roller dyno about possible time slots to tune the DAMPFHAMMER.
Sounds like things are progressing nicely !
 

·
Arouse the DAMPFHAMMER!
Joined
·
8,026 Posts
Discussion Starter · #923 ·
DAMPFHAMMER project:
Driveshaft-assembly is back together in one functional system and mounted on the chassis/engine/gearbox again.

Bicycle part Material property Gas Plumbing Composite material


Notch impact less nut cut with a radius shaped cutter, hold in place by a circular plate with an bolt in a tight fit assembly

Product Auto part Composite material Engineering Metal


Driveshaft assembly. The inner one sealing has an elastic fit and seals without any clamp.

Wheel Tire Car Automotive parking light Land vehicle


With the power of 4 guys we brought this car back on street this Saturday. Got already dawned when we too the picture. Still there are tasks left. The Toyota shifter assembly made huge challenges, seems the guy how mounted in the car may have not totally understood what this is all about, as some part are there were they definitely don't belong to. Idle was bouncing a bit as correction tables for altitude are not tuned. The harness need a review and rework. And some other stuff...

...next Saturday there is some work to do. Got an meeting date with the dyno. I have to check if my buddy also can participate to agree to it. The 6th of November is up for debate.
 

·
Arouse the DAMPFHAMMER!
Joined
·
8,026 Posts
Discussion Starter · #924 ·
DAMPFHAMMER project:
Subject to verification tuning date on 6th of November 2021! Ordered a new radial seal ring (#91206-PHR-003) for the right drive shaft for Saturday. The last one was miffed by the frequent in and out of the shaft.
 

·
Arouse the DAMPFHAMMER!
Joined
·
8,026 Posts
Discussion Starter · #927 ·
it’s alive. Congrats Markus. Major mile stone. It rolls and drives. Awesome.
Thanks man. After 6 years a very very happy day. Just a such formication feeling in my stomach I have felt the first time, just by acceleration. VTC, ign. timing and lambda need a tune...there is much on the table left and to adjust right.

I will tune with the about 20 logs we made to shorten the dyno time for essentials: ign. timing, 2nd stage amount and so on.
 

·
Premium Member
Joined
·
908 Posts
that is fast man. I can hear the acceleration in your tone and the Lotus feels like a Ariel Atom now. that was a little better than 160-170kmh ?

thank you for sharing
 

·
Arouse the DAMPFHAMMER!
Joined
·
8,026 Posts
Discussion Starter · #929 ·
...that was a little better than 160-170kmh ?
It's amazing that formation feeling in the stomach. We drove a RS6 with 800 hp yesterday, it does it not that intense there as the Lotus does it in the first 3 gears. The RS6 a different concept (a bit over 2 tons kerb weight), which is much smoother and powerful then the Lotus, but it can be that the power/weight ratio of the Lotus is better. Theoretical 0.42 hp/kg of the Lotus vs 0.39 hp/kg of the modified 800 hp AUDI RS6. I will test some acceleration times these days too to get a basis for comparison.


For anyone claiming 90 mm TB are no issue, forget it. That 74 mm TB is a real challenge for my buddy to play the clutch sweet spot game with it. At 5 % TB you already have 60 % of WOT MAP. You can see it in the video.
 

·
Premium Member
Joined
·
908 Posts
It's amazing that formation feeling in the stomach. We drove a RS6 with 800 hp yesterday, it does it not that intense there as the Lotus does it in the first 3 gears. The RS6 a different concept (a bit over 2 tons kerb weight), which is much smoother and powerful then the Lotus, but it can be that the power/weight ratio of the Lotus is better. Theoretical 0.42 hp/kg of the Lotus vs 0.39 hp/kg of the modified 800 hp AUDI RS6. I will test some acceleration times these days too to get a basis for comparison.


For anyone claiming 90 mm TB are no issue, forget it. That 74 mm TB is a real challenge for my buddy to play the clutch sweet spot game with it. At 5 % TB you already have 60 % of WOT MAP. You can see it in the video.
it is hard to say which one is faster regardless. The Audi was made to be a smooth sailing playing Poker in the backseat doing 220 kmh and not hearing noise nor feeling the air against it.

your's is a go-kart running from a end of the world scenario type feeling. Some Mad Max sh!t. Like an Atom. Better than a Atom because you have a aero chassis. the atom falls on it's face at 140mph.

I would be interested to see different gear combos on your build, of course of would it is not my money I am spending haha..

Buddy of mine a R6 Audi V8 with dual oem meth injection systems on each intake manifold. It is a NA build, not that much HP but still a fun ride. And cool Audi does oem meth injection
 

·
Arouse the DAMPFHAMMER!
Joined
·
8,026 Posts
Discussion Starter · #932 ·
I would be interested to see different gear combos on your build, of course of would it is not my money I am spending haha..
This maybe would be the case, as the gearbox leaks. We assume to have a hairline crack.

Buddy of mine a R6 Audi V8 with dual oem meth injection systems on each intake manifold. It is a NA build, not that much HP but still a fun ride. And cool Audi does oem meth injection
I didn't know Audi was doing that for series. Which chassis series and year was it?

Now this is what we came for !! I can hear the excitement. I love it. Such a great sounding engine. Definitely likes to rev. Very happy for you the car looks and sounds amazing.
Thanks @KBuilt. This beast pulls so fast into 9250 rpm into the rev limiter that shift time get a huge part of time during acceleration. Sound-wise it is different to any modified K-series of Honda I heard before. Yesterday I've tuned WOT for VTC, lambda and ignition as well tried some 2nd stage duties cycles before the 2nd fuel rail popped of at #1 injector. We had great luck, no fire. None of my guys touched it during the process, I assume it to be forgotten by the previous guys, they had it after tuning in Jan. 2020 and March 2020. But they had no work to do there during this time. I won't blame them. But we are alarmed and will check every screw again. This is such an adventure ;).
 

·
Registered
96 civic HX K24a
Joined
·
2,022 Posts
This maybe would be the case, as the gearbox leaks. We assume to have a hairline crack.

I didn't know Audi was doing that for series. Which chassis series and year was it?

Thanks @KBuilt. This beast pulls so fast into 9250 rpm into the rev limiter that shift time get a huge part of time during acceleration. Sound-wise it is different to any modified K-series of Honda I heard before. Yesterday I've tuned WOT for VTC, lambda and ignition as well tried some 2nd stage duties cycles before the 2nd fuel rail popped of at #1 injector. We had great luck, no fire. None of my guys touched it during the process, I assume it to be forgotten by the previous guys, they had it after tuning in Jan. 2020 and March 2020. But they had no work to do there during this time. I won't blame them. But we are alarmed and will check every screw again. This is such an adventure ;).
Things always happen after the first few road tests. I had the shift linkage fall off my car the second time I drove it with the b series because I put the washer on backwards 😅 it sounds like a real high rpm screamer.
 

·
Registered
Joined
·
697 Posts
So where would you set the limiter for OEM valves on Toda springs, Toda A3 cams, forged H-shaft rods and CA625+ rod bolts?
I run the same forged Mahle pistons as you, just higher due to machining, but chickened out setting the the hard limiter to 9100.

Regarding TB, I found even the 70mm S90 garbage regarding throttle response.
 

·
Arouse the DAMPFHAMMER!
Joined
·
8,026 Posts
Discussion Starter · #935 ·
Things always happen after the first few road tests.
Seems there is an amount of issues you only see when you run the system, especially under load conditions.

So where would you set the limiter for OEM valves on Toda springs, Toda A3 cams, forged H-shaft rods and CA625+ rod bolts?
Valvetrain-wise TODA recommended me not to go over 9200 rpm as the begin to float at 9500 rpm. The crank assembly will be fine with 9200 rpm: Mahle 86.5 mm bore with 12 ccm dome pistons, forged steel rod below 500 g and enough bearing clearances, as you already have, as far as I know.

Regarding TB, I found even the 70mm S90 garbage regarding throttle response.
Power-wise it is necessary. I am thinking about a DBW or a dual cable-driven TB. The excenter distance is to less to have enough control of the low load. But that is a comfort thing, which not really matters on a race engine application.
 

·
Registered
Joined
·
697 Posts
Thx, interesting infos.
I once compiled TB size data and found for example that the 997 all the way to the 991.2 GT3RS used a single 82mm TB. At 440HP this equals to 12 mm2/HP, at 520HP to 10.15 mm2/HP.
There are tuners that claim lower pressure losses with a 93mm TB. This would yield 13,06 mm2/HP.
At 250 HP and 90mm TB size, you end at 25 mm2 /HP. It makes no sense at least from a pure cross sectional standpoint. It might be useful to maintain a certain geometry.
I found a number of about 10 mm2/HP to be sufficient before significant power losses occur. For 250HP some 56-57mm are OK. Factory was 60 mm or 14,13 mm2/HP at 200HP.
Porsche was still fine with 10,15 mm2/HP on the 991.2 GT3RS.

From an empirical standpoint, you don't need such a big TB.

Now for a pre-compressor TB, this will look slightly different as you increase air velocity a lot.

Font Material property Pattern Number Parallel
 

Attachments

·
Arouse the DAMPFHAMMER!
Joined
·
8,026 Posts
Discussion Starter · #937 ·
Thanks for your shared data @Lotus. Here we have around 12.5 mm²/hp.

From an empirical standpoint, you don't need such a big TB.
If you see a TB as a part of continuous flowing system you are right. The Plenum pressure loss of 70 mm vs 74 mm is just neglectable on a 2000 ccm engine. When it comes to the DAMPFHAMMER concept, things changes. Pressure waves are more sensitive regarding magnitude loss when it comes to cross section changes. It is part of the oscillation system. Did you ever here such a K20 sound? I guess not. The DAMPFHAMMER concept is designed to use natural forced induction effects much more efficient as the stuff you find in the aftermarket. This causes a different noise outside. I have resonances in cabine in low engine speeds, that is so impressing who silent this beast is at idle, sound just like a OEM K20. Floor it and you see the other side of this torque beast, this a bit of Dr. Jeckll and Mr. Hyde type behaviour you find in the TB, which reacts like that very sensitive. I haven't that issues getting that beast rolling as my buddy, it keeps it below 2000 rpm. But it is a challenge, sweet spot playing at clutch so to say ;).

Tomorrow I will take some runs at various 2nd fuel stage amounts and fuel time phasing's. I am really looking forward to that :D.


Some night testing of 2nd fuel rail staging. I still investigating the influence on VE of this.
 

·
Registered
96 civic HX K24a
Joined
·
2,022 Posts
Thanks for your shared data @Lotus. Here we have around 12.5 mm²/hp.

If you see a TB as a part of continuous flowing system you are right. The Plenum pressure loss of 70 mm vs 74 mm is just neglectable on a 2000 ccm engine. When it comes to the DAMPFHAMMER concept, things changes. Pressure waves are more sensitive regarding magnitude loss when it comes to cross section changes. It is part of the oscillation system. Did you ever here such a K20 sound? I guess not. The DAMPFHAMMER concept is designed to use natural forced induction effects much more efficient as the stuff you find in the aftermarket. This causes a different noise outside. I have resonances in cabine in low engine speeds, that is so impressing who silent this beast is at idle, sound just like a OEM K20. Floor it and you see the other side of this torque beast, this a bit of Dr. Jeckll and Mr. Hyde type behaviour you find in the TB, which reacts like that very sensitive. I haven't that issues getting that beast rolling as my buddy, it keeps it below 2000 rpm. But it is a challenge, sweet spot playing at clutch so to say ;).

Tomorrow I will take some runs at various 2nd fuel stage amounts and fuel time phasing's. I am really looking forward to that :D.

The sound of your engine really is incredible. If you can on the dyno, place the camera in front and by the exhaust so we can hear both the induction and exit noises 😎
 

·
Arouse the DAMPFHAMMER!
Joined
·
8,026 Posts
Discussion Starter · #939 ·
The sound of your engine really is incredible. If you can on the dyno, place the camera in front and by the exhaust so we can hear both the induction and exit noises 😎
So much camera's. I need a sponsor :D!
 

·
Registered
Joined
·
697 Posts
of course, a small TB creates an acoustic impedance impeding with employing the intake piping as part of the resonance system. My old intake system had such a strong resonance at 4000 rpm. Thing is that strong resonances come with big dips as well. Maybe worth considering moving a smaller TB up the intake pipe with a litte response time as a trade off.

Regarding sound this is hard to judge in a video. To me, it sounds very much dominated by the exhaust sound on the outside. The cabin video is more dominated by the intake sound with some nice bark in the 6-7k region. You have not reved it much higher yet. (Correction: it was reved higher)

From just a change in intake pipe length and type of ITG air box I can confirm that sound characteristics can change a lot from an ITB like sound with the side entry ITG carbon airbox with long pipe to a more muted plenum type of sound with 20cm less long intake piping and a aluminium straight ITG airbox using the very same foam filter element.
 
921 - 940 of 943 Posts
Top