Hyperblade's KP61 Racecar "KP61R" Discussion

[Hyperblade]

26 minutes ago, Roman said:

Nice work on that DTM panel! Looks good, been thinking about doing something similar. 

However will you be doing anything to index them or add a keyway or something, so you cant plug the wrong plug into the wrong one? 

Or colour coding them or something.

(I'm here to steal ideas)

Yeah so all those thoughts crossed my mind when I did it. At the moment I have none of that.

Each connector is numbered on the loom and the bulkhead plate is numbered, but that's obviously not a fool proof solution.

Keying would be hard, you would have to machine the connectors down to put it in, and I'm not sure how much material is there to do that.

I had thought of printing color coded wrappers for them then glueing them on.

Can't use dummy pins as each connector doesn't have many to begin with.

I have made each connector very similar, e.g. 12v always on pin 1, 5v on 2, sensor ground 3, so it limits the risk a little bit, and coils/injectors are all interchangeable with no risk.

However my biggest concern is swapping the EWP with the ECU ground, if that happens then it's a straight path from fuse to ground.

So no solid solution at present, but open to ideas.

 

 

[Roman]

Okay soooo

They had 184.5 wheel horsepower. 
Then fitted ITB, and now they have 185.6 wheel horsepower. 
So a 1.1 horsepower gain in real life.
But they now for some reason have 60.4 horsepower drivetrain loss instead of 56.6 horsepower drivetrain loss. 

Did someone pour sand in the gearbox when doing ITB swap? haha.
This is why I hate "at engine" power figures.

[kpr]

As above,  I have been looking at some of the stuff they post. as been playing with a k24.    They quote all these different gains in bhp,   but the wheel hp on the same graph says something different.  also mega driveline losses.   Ive roughly overlaid the graphs    blue is the wheel hp.    red "engine" power.     light lines stock intake,  dark itb.    

 

 

Looking at the wheel power.  the stock intake manifold would be a quicker car.    unless you could run between 8000 & 9000 rpm the whole time.  even then  wouldnt be anything in it.

Why,    The itb's   will probably flow more.  but the runners are way to short to make any jam over the whole rev range.   stock inlet will be running out of flow and or slightly too long to make power at 9k
ITB's only work good if you dial in the runner length and have the flow to go with it.

Seems to be super common with K series stuff.  even the factory inlets.   They are too short with big runners.   or long with small runners.

I think those itb's you have will be a touch on the small side.   possibly ok.  but can get away with over sizing the intake a bit.  not so much under sizing it.   if make the runners small enough to gain in the bottom end (talking rpm you will never use in circuit car)  will lose top end.   if a bit too big, not much happens.  not trying to lecture you,  just wouldn't be fun to have to do it twice if you didn't have to.

 

This is the intake i just made for k24. Big long runners.   gains everywhere over RBC honda inlet.  which is spose to make more peak power that the stock ep3 one they compared the itbs too. 

 

 

 

 

 

[Hyperblade]

19 hours ago, Roman said:

Okay soooo

They had 184.5 wheel horsepower. 
Then fitted ITB, and now they have 185.6 wheel horsepower. 
So a 1.1 horsepower gain in real life.
But they now for some reason have 60.4 horsepower drivetrain loss instead of 56.6 horsepower drivetrain loss. 

Did someone pour sand in the gearbox when doing ITB swap? haha.
This is why I hate "at engine" power figures.

You have to love the drivetrain loss going up just at the end of the graph to produce a nice curve, very convenient for them...

To be fair the ambient temperature was different on the day.

But yeah, people need to stop with BS made up figures.

16 hours ago, kpr said:

As above,  I have been looking at some of the stuff they post. as been playing with a k24.    They quote all these different gains in bhp,   but the wheel hp on the same graph says something different.  also mega driveline losses.   Ive roughly overlaid the graphs    blue is the wheel hp.    red "engine" power.     light lines stock intake,  dark itb.    

 

Looking at the wheel power.  the stock intake manifold would be a quicker car.    unless you could run between 8000 & 9000 rpm the whole time.  even then  wouldnt be anything in it.

Why,    The itb's   will probably flow more.  but the runners are way to short to make any jam over the whole rev range.   stock inlet will be running out of flow and or slightly too long to make power at 9k
ITB's only work good if you dial in the runner length and have the flow to go with it.

Seems to be super common with K series stuff.  even the factory inlets.   They are too short with big runners.   or long with small runners.

I think those itb's you have will be a touch on the small side.   possibly ok.  but can get away with over sizing the intake a bit.  not so much under sizing it.   if make the runners small enough to gain in the bottom end (talking rpm you will never use in circuit car)  will lose top end.   if a bit too big, not much happens.  not trying to lecture you,  just wouldn't be fun to have to do it twice if you didn't have to.

 

This is the intake i just made for k24. Big long runners.   gains everywhere over RBC honda inlet.  which is spose to make more peak power that the stock ep3 one they compared the itbs too. 

 

Yep, here's another brilliant one from them, I'm sure you've already looked at it.

https://www.tegiwaimports.com/blog/?p=2443

I got caught out by this one when I brought my current ultra street manifold, i'm much more careful looking at these things now.

 

Lecture away! (happy for anyone too), I always like considering all the possibilities and discussing this stuff with people who have actual real world experience.

 

I agree slightly larger ITB's would be ideal so that you have a bit of wiggle room, but the feedback I've had is the normal Jenvey ITB's worked the best on a dyno(on built k20 in CRX) when comparing multiple different types, so if i match them in design I'm confident that it should perform at least better than the skunk2 intake I have currently.

But I'm limited by what you can easily get off motorbikes due to the pricing, I had a look around at other options, but nothing stood out.

However I do have a couple of other things planned to throw into the mix.

• Outboard injection.
• Variable velocity stacks (I'm on the hunt for a standard S1000RR airbox to get the mechanism)
• Intake will be using ram air to create pressure through filter and into air box.
• I have heaps of room to play around with lengths of stacks (which will be 3d printed so not expensive to make).

 

Do you have any good calculators you use for working out lengths of intake runners? I also need to find the measurement of valve to intake flange to use in them.

Just for reference car normally runs between 6000 to 9000rpm in a lap with lowest being 4700 rpm at hairpin. Being light and having the torque allows me to use more of the rev range, which helps with not overworking the tyres.

 

 

[Roman]

Hey I've got a standard S1000RR airbox - but I bought the wrong one.
It didnt quite fit because it must be the box for the slightly different variation of throttles from the earlier or later ones. 
However it was definitely interesting to look at the mechanism for how it adjusts trumpet length, and the injector positions. 

My consensus was that it was interesting to look at, but I dont think it would have added enough benefit for a car engine to be worth buying another one that fit correctly when adding to a car engine.

What I mean is, the box has shorter runners for higher rpm. But those bikes run to 14,000rpm so "low" rpm might be below 10k haha. 
It's got a massive span of rpm it needs to operate compared to a car engine, which is why I think the dual length runner was valuable.
Also why the outer injectors earned their keep.  

It was also interesting that the position of the outer injectors was so incredibly far from the runners, when the upper trumpets were lifted up for high rpm.
It must have essentially just been fogging the whole airbox. Like maybe... 150mm away from start of the bellmouth.

I will take some pictures and measurements when I'm next over where it is.

Can send it to your for cost of post if you're interested but it wont fit.
 

[kpr]

Yup, thats the same inlet test i was referring to.   

Have you looked into s65 bmw throttles?  they are 52mm, spacing should be pretty close for k series.  the also have an oval outlet  similar shape to the port.   Have a separate dbw module  that can be used if wanted to go that way. but is known to crap out. 

I'd  probably target  8000rpm  maybe a touch under for your intake runner length.   about 320mm from port face should get you ballpark.    you want to  get the intake tuning right where the engine naturally wants to make peak power.  will make more power and fatten it up that way.  rather than kinda trying to force it to make more power right up top. like your current intake looks to be doing.    The VCT  (cam timing)  is also your friend here.  you can use it to hang onto the power past peak a bit longer.   If do everything right it should at least match the power it has now right up top 8500- 9k and make a bunch more 7500- 8000rpm plus more through the mid range 

The runner length on the manifold in video is around the 350mm mark, as was targeting bit lower rpm. 

 

 

 

[Hyperblade]

5 hours ago, Roman said:

Hey I've got a standard S1000RR airbox - but I bought the wrong one.
It didnt quite fit because it must be the box for the slightly different variation of throttles from the earlier or later ones. 
However it was definitely interesting to look at the mechanism for how it adjusts trumpet length, and the injector positions. 

My consensus was that it was interesting to look at, but I dont think it would have added enough benefit for a car engine to be worth buying another one that fit correctly when adding to a car engine.

What I mean is, the box has shorter runners for higher rpm. But those bikes run to 14,000rpm so "low" rpm might be below 10k haha. 
It's got a massive span of rpm it needs to operate compared to a car engine, which is why I think the dual length runner was valuable.
Also why the outer injectors earned their keep.  

It was also interesting that the position of the outer injectors was so incredibly far from the runners, when the upper trumpets were lifted up for high rpm.
It must have essentially just been fogging the whole airbox. Like maybe... 150mm away from start of the bellmouth.

I will take some pictures and measurements when I'm next over where it is.

Can send it to your for cost of post if you're interested but it wont fit.
 

Those are good points about dealing with the rev range. I've looked at the videos of how it works and it is a very clever design in it's simplicity.

Still want to try it just to see the impact, I'm trying to get everything out of a stock K20 without opening it, so every little bit counts!

3 hours ago, kpr said:

Yup, thats the same inlet test i was referring to.   

Have you looked into s65 bmw throttles?  they are 52mm, spacing should be pretty close for k series.  the also have an oval outlet  similar shape to the port.   Have a separate dbw module  that can be used if wanted to go that way. but is known to crap out. 

I'd  probably target  8000rpm  maybe a touch under for your intake runner length.   about 320mm from port face should get you ballpark.    you want to  get the intake tuning right where the engine naturally wants to make peak power.  will make more power and fatten it up that way.  rather than kinda trying to force it to make more power right up top. like your current intake looks to be doing.    The VCT  (cam timing)  is also your friend here.  you can use it to hang onto the power past peak a bit longer.   If do everything right it should at least match the power it has now right up top 8500- 9k and make a bunch more 7500- 8000rpm plus more through the mid range 

The runner length on the manifold in video is around the 350mm mark, as was targeting bit lower rpm. 

Skunk 2 Ultra Street Manifold Runners

Just measured the Skunk 2 Ultra street Manifold runners as a data point.

These are all rough measurements as it's still on car and I'm not taking it off as it's a full days job (one of the reasons why I want to go to ITB's).

Runner length 155mm from port face to velocity stack tip (estimated)

Outer diameter where runner goes into manifold is 60.50mm, I think there is a fair bit of wall thickness assume 5mm which would make 50.50mm inside diameter.

S65 ITB's

S65 ITB's are out of my price range at the moment, plus the ones I have are a seriously nice bit of kit in terms of packaging and weight. I'm happy to use these ones to get experience with them, if they work better then what I have then that means I can sell the old skunk2 setup and look at other options. Will only cost me the ITB's and filament which is not a lot in comparison to off the shelf ITB's, plus i'm now sold on electronic ITB's since i've spent time and wired for them (obviously can still run cable if I need to), but not a chance I'm going with dbw module that's know to crap out... 

I had looked at the efi hardware ones back when i was first looking for options, but they add up quickly with all the linkage and accessories needed.

Runner Length

So in terms of runner length for the Jenvey ITB's (EP3 version BUT NOT the Tegiwa compromised version) they look to me

Runner - ITB - Velocity Stacks = Total

85mm - 66mm(tapered) - 90mm(tapered) = 241mm

So I was planning to match that with

85mm - 78mm(tapered) - 78mm(tapered) = 241mm

But based on your suggestion it would be

85mm - 78mm(tapered) - 157mm = 320mm

So it's interesting to see such a big difference between your suggestion and theirs!

How does a tapered velocity stack affect things, my thinking is that as it's expanding it's slowing the pressure waves, so making it behave as if it's a longer velocity stack? How do you calculate that effect into it?

[kpr]

one word ->  packaging

they will be aiming for the 3rd harmonic (itb's, the skunk2 maybe even 4th)     im aiming for the 2nd, which is stronger  = more power

tapered is said to accelerate the air.  maybe.    but are also losses in the pipe, so need to go bigger further from head to keep flow the same as.    real world isn't much effective length difference with taper, unless is way too much. or turns into a massive bell mouth, which will act like the pipe ends part way down the bellmouth into the runner, rather than the face.  in your case yeah i would taper out soon as get past the throttle plate.

Example of engine not caring too much if runners are too big;  The runners on the manifold i made are 2.25"  tube.    think its 53 or 54mm id.  half way around the bend it starts tapering down to the port.  so yeah its big.  bigger than the rbc intake and huge compared to the stock k24 manifold.   but still gains power right down at 4000rpm.  close to 10% at that point,  so not a small gain either.

 

Another example. The only place my 4age with 52mm throttles  drops below a stock engine is under 2000rpm.

 

[Truenotch]

That was some great wet driving! The car looked like it was hooked up and you weren't afraid to use the grip. Nice work.

I'm hoping to have my car in South Island later this year. Hopefully we can meet up at a track somewhere. 

[Hyperblade]

15 hours ago, kpr said:

one word ->  packaging

they will be aiming for the 3rd harmonic (itb's, the skunk2 maybe even 4th)     im aiming for the 2nd, which is stronger  = more power

tapered is said to accelerate the air.  maybe.    but are also losses in the pipe, so need to go bigger further from head to keep flow the same as.    real world isn't much effective length difference with taper, unless is way too much. or turns into a massive bell mouth, which will act like the pipe ends part way down the bellmouth into the runner, rather than the face.  in your case yeah i would taper out soon as get past the throttle plate.

Example of engine not caring too much if runners are too big;  The runners on the manifold i made are 2.25"  tube.    think its 53 or 54mm id.  half way around the bend it starts tapering down to the port.  so yeah its big.  bigger than the rbc intake and huge compared to the stock k24 manifold.   but still gains power right down at 4000rpm.  close to 10% at that point,  so not a small gain either.

 

Another example. The only place my 4age with 52mm throttles  drops below a stock engine is under 2000rpm.

 

Ahh that would make logical sense.

I'm not sure Skunk2 were aiming for any harmonic it looks more like it's designed for turbos.

320mm long looks close to a lot of things, may have to curve the velocity stacks to fit that in but that's all doable if being 3d printed. Will be another learning experience.

Thanks for the feedback!

 

[kpr]

Yeah most people don't try anything that long, due to fitment / too hard basket in a lot of engine bays.   But its really where the advantage is.    when it comes to getting it dyno tuned. Id suggest having a way to try 20-30mm either  way from that 320 length.  is enough to see the power curve move around, to see if your in the right place.   even though can shuffle it a bit with the vct , there still a litte bit to be had getting it bang on. 

If going to make a plenum for it. make it big as possible. same deal with feed pipe.

Yeah kinda re the skunk2 manifold,    the runner length thing works just the same on turbo stuff though.   It keeps coming back to the packaging thing and being a diddle to make.  shiny parts sell. 

[Hyperblade]

On 23/05/2023 at 17:15, kpr said:

Yeah most people don't try anything that long, due to fitment / too hard basket in a lot of engine bays.   But its really where the advantage is.    when it comes to getting it dyno tuned. Id suggest having a way to try 20-30mm either  way from that 320 length.  is enough to see the power curve move around, to see if your in the right place.   even though can shuffle it a bit with the vct , there still a litte bit to be had getting it bang on. 

If going to make a plenum for it. make it big as possible. same deal with feed pipe.

Yeah kinda re the skunk2 manifold,    the runner length thing works just the same on turbo stuff though.   It keeps coming back to the packaging thing and being a diddle to make.  shiny parts sell. 

How important is getting the runner straightended up before the port?

 

e.g. 150mm length

 

vs 85mm

Obviously the longer I make them the smoother it gets, but do need to take into account velocity stacks and potentially having to go 90 degrees with them to fit the total 320mm length in.

 

 

[kpr]

probably fine long as the bends arent super aggressive.   assuming you are still using the 47mm throttles. probably best to have them on the shorter manifold, then can taper up in diameter sooner

Interestingly  i just tuned a k20  on my dyno.   had really short intake with big plenum  and big short headers.  done as expected.    made 202hp  and weak through the middle. 

[Hyperblade]

10 hours ago, kpr said:

probably fine long as the bends arent super aggressive.   assuming you are still using the 47mm throttles. probably best to have them on the shorter manifold, then can taper up in diameter sooner

Interestingly  i just tuned a k20  on my dyno.   had really short intake with big plenum  and big short headers.  done as expected.    made 202hp  and weak through the middle. 

48mm throttle plate, 46mm (same size as port) outlet to runner. 53mm inlet to velocity stack.

Are you going to remake the intake for it? Would be interesting to see another back to back but on k20.

 

[kpr]

probably not, just come in for a tune.    But i sold the intake off the ep3 , to another guy  with a k24.  k20 head  and stage 3 cams, so better head and bigger cams.   Done the initial tune on my dyno when it had a skunk2 ultra race?  intake.  which is the red below,  and the ep3 k24 in brown.    He lives quite far away, so remote tuned it to get the afr right when he swapped to my inlet manifold.   had to add a lot of fuel through the middle and some up top.  so probably pretty close to the ep3 power curve now.     Don't see why the k20 wouldn't do the same thing.  the heads flow good and have plenty of cam from factory, so good gains in getting the bolt ons right.

 

this is the k20

 

[kpr]

Also just looking back at your  vct/vvti map.     seems a bit low.  yours should have the 50degree vct pulley.  All the ones Ive done like more advance through the middle, pretty much max it out to 50. 

[Hyperblade]

16 hours ago, kpr said:

probably fine long as the bends arent super aggressive.   assuming you are still using the 47mm throttles. probably best to have them on the shorter manifold, then can taper up in diameter sooner

Interestingly  i just tuned a k20  on my dyno.   had really short intake with big plenum  and big short headers.  done as expected.    made 202hp  and weak through the middle. 

 

85mm long = 

To me that looks to sharp on the inside of the outer runner (middle runners look fine throughout).

100mm long = 

 

110mm long

120mm long = 

 

 

5 hours ago, kpr said:

Also just looking back at your  vct/vvti map.     seems a bit low.  yours should have the 50degree vct pulley.  All the ones Ive done like more advance through the middle, pretty much max it out to 50. 

Yeah haven't changed pulley so will be 50 degree one, interesting, might have to end up putting it back on the dyno after the ITB's to look at all that. I have been offered the use of one, just need to upskill in being able to tune.

 

 

 

 

[kpr]

100 looks fine to me

most things like all the advance through the middle.    the point at high rpm where the cam wants to retard , can vary quite a bit depending on intake and exhaust tuning.