Hyperblade's KP61 Racecar "KP61R" Discussion

[Hyperblade]

2 hours ago, Roman said:

Have you noticed much of a difference with handling, with the lighter motor mounted a bit further back? 

 

So this is a hard question to answer, here goes...

 

Before I put the k20 in I was having suspension issues, and it turned out valving of shocks were wrong (to hard), I got that fixed but never had a chance to run on track and check the results.

 

The rear brake pads (that were to aggressive) were also put in before the engine change (I'll explain why this is important later)

 

So along with the 30kg lighter engine and it being set back a long way giving 52/48% weight distribution (previous 57/43%).

 

The new alignment also changed the front camber from 3degrees to 4.25

 

Along with the new engine we lengthened the wheel base front and rear 50mm each for total of 100mm (same as ae86 now)

 

The rear diff has changed from 4 angled links to 3 link with watts linkage.

 

The rear lsd has new oil and been tightened up.

 

So definitely just a single change like everyone recommends doing...

 

So it makes it harder to pinpoint a single cause for improvement.

 

I can say:

The car is more predictable on the limit, it's really controllable when it goes over. This is likely because of the longer wheelbase.

 

The rear grip through the corner and out of it is substantially better, this is likely because of 3 link. But weight distribution can play a part.

 

I feel turn in is better, with the previous setup it really wanted to understeer in and also out of corners. I feel the understeer is a lot better.

This would be down to weight distribution but can be affected by the other stuff.

 

However in all of this is the issue I've been having with rear brakes locking so I've had to be gentle on brakes and a lot longer on them, this has meant it's really really hard to consistently hit the apexes as I don't know where I'm actually going to stop so I always leave a lot of contengancy in the braking zone, that means I end up finishing my braking early which then means I'm coasting to corner so don't have the weight over front wheels to help turn in.

 

So I think it's helped but still need to adjust my driving style to suit now.

 

Overall I have a lot more faith in the handling then I did before which allows me to push it more. It feels more complete as a package. So I think it has made a difference.

 

TLDR: yes you should put a 180hp Prius motor in your carina set way back it would handle way better then having that heavy cast iron block hanging over the front end. Or dropping the whole lot in the back might be easier long term.

[Truenotch]

Gutted about the clutch! @Rhyscar had an Exedy HD clutch plate blow to bits behind his standard blacktop 4AGE and there's plenty of stories from others about breaking the plates etc. Hopefully you'll have no problems once you chuck a decent one in there. 

Looks like the handling on this car has come a long way too. I can see the extra confidence in your vids. Everything should come together once you've got the everything dialled enough to do constant laps. Keep it up.

[Hyperblade]

On 18/08/2022 at 16:09, Truenotch said:

Gutted about the clutch! @Rhyscar had an Exedy HD clutch plate blow to bits behind his standard blacktop 4AGE and there's plenty of stories from others about breaking the plates etc. Hopefully you'll have no problems once you chuck a decent one in there. 

Looks like the handling on this car has come a long way too. I can see the extra confidence in your vids. Everything should come together once you've got the everything dialled enough to do constant laps. Keep it up.

Thanks, its been a hard slog, once I can stop worrying about the car I can then focus on my driving so should be some good improvement still to come.

 

It's always easy to forget all the little issues you have with racecars and the improvements you make over the years. And the actual success you're had. As your so focused on the next issue.

That's why it's cool sometimes looking back through the old videos and realising how far it's come.

 

Once everything is sorted, I have worked out how I can put a flat floor under whole car including rear axle, so that's the next long term project, but no point doing that until happy with car handling now.

 

 

 

 

[Roman]

Ahh man there's always something eh!

Drive from last shakedown looked good, stoked to see it's making steady improvements. 

Would love to check out your car one day, love it. 

[Hyperblade]

10 hours ago, Roman said:

Ahh man there's always something eh!

Drive from last shakedown looked good, stoked to see it's making steady improvements. 

Would love to check out your car one day, love it. 

Anytime your down here in Chch (or anyone else who wants to see it) just give a yell.

[cbDrift]

Had to sign up just so i could reply after i got your youtube reply and saw you uploaded your map.

Its a very similar tune to my jdm civic k20a timing wise - very close all the way through under load - a few deg more at the top end than me but im paranoid about not wanting any knock. generally within 2ish deg of mine under full load with mine running a bit less than you 99% of the time

But your cam angle map is totally different to mine - and on these k20a engines - it makes all the world of difference getting that right in all conditions with an n/a engine.

i gained a "buttload" (technical term) of top end when i got the target cam angle to actually match up with actual angle using this target cam angle map on my haltech

this is from my jdm type r k20a in a 2005 civic ep3 - the engine is untouched apart from intake and injectors and a decat

the difference between accurate cam tracking and having it waffle around vaguely in the range of the target is amazing - I got a tonne of drivability and my top end power when i had good control of the cam angle. 2deg can make a difference to how the car feels when driving - and cold oil heavily affects the cam angle tuning vs up to temp oil.

having said that - it looks like the link handled pid stuff totally differently to the haltech so i have no idea how accurate the link will track the target cam angle.

Either way - if this helps to improve your drivability - mint!  if it doesnt - just as mint

Have fun - your starlet is an awesome build and thank you for posting your map to take a look at

I'd be really interested to see how accurate the link is able to track the target cam angle with the actual cam angle (even a screenshot of the two traces overlaid)

[Hyperblade]

15 minutes ago, cbDrift said:

Had to sign up just so i could reply after i got your youtube reply and saw you uploaded your map.

Its a very similar tune to my jdm civic k20a timing wise - very close all the way through under load - a few deg more at the top end than me but im paranoid about not wanting any knock. generally within 2ish deg of mine under full load with mine running a bit less than you 99% of the time

But your cam angle map is totally different to mine - and on these k20a engines - it makes all the world of difference getting that right in all conditions with an n/a engine.

i gained a "buttload" (technical term) of top end when i got the target cam angle to actually match up with actual angle using this target cam angle map on my haltech

 

this is from my jdm type r k20a in a 2005 civic ep3 - the engine is untouched apart from intake and injectors and a decat

the difference between accurate cam tracking and having it waffle around vaguely in the range of the target is amazing - I got a tonne of drivability and my top end power when i had good control of the cam angle. 2deg can make a difference to how the car feels when driving - and cold oil heavily affects the cam angle tuning vs up to temp oil.

having said that - it looks like the link handled pid stuff totally differently to the haltech so i have no idea how accurate the link will track the target cam angle.

Either way - if this helps to improve your drivability - mint!  if it doesnt - just as mint

Have fun - your starlet is an awesome build and thank you for posting your map to take a look at

I'd be really interested to see how accurate the link is able to track the target cam angle with the actual cam angle (even a screenshot of the two traces overlaid)

Welcome to the forum!

Unfortunately your talking way over my head, i'm just not up to speed technically on all of that stuff as much as I want to be, I just haven't had the time to really sit down and understand it all and be able to tweak it.

I should mention Dave said he usually has the timing backed off a couple of degrees.

The other thing to mention is that on the Dyno Jon struggled to get temp into it including the oil (5w40) which sat at about 80 degrees if i remember correctly (on track oil is hitting 120+)

Due to:

• The sensor reading 9-11 degrees lower than what the engine temp actually was
• The electric water pump control just not working well at all (hence I put in new thermostat + bypass hose)

I can do you one better though, here's the full log from session 4, i basically have everything logged as it has heaps of memory.

https://drive.google.com/file/d/1x3suRFYwUip95PEAx97Et83RMrr0hbNC/view?usp=sharing

 

I haven't updated the main thread, but current plan is to redo intake piping to be straight which means new 3d printed top half of the manifold so I can straighten throttle body, this should at least eliminate that from being a possible issue as I think the triple bend for the air to get into the runner is actually the main issue vs the plenum volume. I want to do that first as it's just keeps niggling at me(and I would like to know if I'm on the money or not around that stuff) and and it gives me more time to plan the quad throttles to get best results.

[Roman]

16 hours ago, cbDrift said:

 

I'd be really interested to see how accurate the link is able to track the target cam angle with the actual cam angle (even a screenshot of the two traces overlaid)

This is not from his engine, but from a Toyota VVTI setup. Can generally stay on target within 0.1-0.2 degrees, but needs to catch up on fast transients - cant do much about mechanical latency.

But the Link PID works well, there is a compensation table for oil viscosity when oil is cold. 

[kpr]

I was going to comment  about probably changing the cam timing map. so  it doesn't go to zero cam advance when throttle is closed.   due to the mechanical time it takes the cam to re advance when get back on the throttle.
but looked in the log and looks like it keeps real well. nice one mr honda.  so isn't really that much of an issue. possibly a little more crisp on the throttle if changed it.

As for  what cam timing it needs. will need to be done per engine.   unless 100% stock to 100% stock.    as changes to the intake and exhaust will change what cam timing it likes.
The shape of  the cam timing map  looks  right.    starts to retard at high rpm etc

This as part of the log   @Hyperblade  posted.   cam stuff at the bottom

 

The vvti control works real well even on my old g4 link. 

 

[Hyperblade]

58 minutes ago, kpr said:

I was going to comment  about probably changing the cam timing map. so  it doesn't go to zero cam advance when throttle is closed.   due to the mechanical time it takes the cam to re advance when get back on the throttle.
but looked in the log and looks like it keeps real well. nice one mr honda.  so isn't really that much of an issue. possibly a little more crisp on the throttle if changed it.

As for  what cam timing it needs. will need to be done per engine.   unless 100% stock to 100% stock.    as changes to the intake and exhaust will change what cam timing it likes.
The shape of  the cam timing map  looks  right.    starts to retard at high rpm etc

This as part of the log   @Hyperblade  posted.   cam stuff at the bottom

 

 

The vvti control works real well even on my old g4 link. 

 

Thanks for posting that screenshot, helps me understand what you are all talking about!

[kpr]

Yeah you can see  the actual timing (yellow) misses the target (pink)   by a little when you get back on the gas.  but by the time your at full throttle its matching the target. 

top one is your current  "vvt"  map.    since race car and assuming you dont care about fuel economy,  I'd  run something more like the bottom.  or a less aggressive ramp at least.   so your always on target when get back on the gas.  Not really much of an issue in your case but thought would explain it better. 

 

Ive compared mine, which essentially mimics at 1j/2j   setup vs @Roman daves  1nz setup and seems to react pretty similar.   yours seems a little faster.   either a honda thing or the control is a little better in g4x

[Hyperblade]

30 minutes ago, kpr said:

Yeah you can see  the actual timing (yellow) misses the target (pink)   by a little when you get back on the gas.  but by the time your at full throttle its matching the target. 

top one is your current  "vvt"  map.    since race car and assuming you dont care about fuel economy,  I'd  run something more like the bottom.  or a less aggressive ramp at least.   so your always on target when get back on the gas.  Not really much of an issue in your case but thought would explain it better. 

 

Ive compared mine, which essentially mimics at 1j/2j   setup vs @Roman daves  1nz setup and seems to react pretty similar.   yours seems a little faster.   either a honda thing or the control is a little better in g4x

That's brilliant, I understand what your getting at with the changes now. Even if it was 15 to 25 (assuming degrees) then it would take a big chunk of not being on target out of that curve.

[kpr]

Yeah numbers are  degrees, but but dont reference to anything other than the pulley position . 0 being fully retarded.   
 from memory you can change it, so it shows referenced to crank position.  but it just makes it confusing to setup/tune

[kpr]

Oh and the intake plenum size.  probably aren't loosing any power there, unless your loosing some  effect from the intake tube.  bigger plenum damping out the pressure waves, unsure how much of a thing that is.    There will be a little bit in getting the intake tube the right length and size. but wouldn't expect big numbers  from it. 

[Hyperblade]

On 21/02/2023 at 21:56, kpr said:

Oh and the intake plenum size.  probably aren't loosing any power there, unless your loosing some  effect from the intake tube.  bigger plenum damping out the pressure waves, unsure how much of a thing that is.    There will be a little bit in getting the intake tube the right length and size. but wouldn't expect big numbers  from it. 

Agree on plenum size, everything I have read is that you can't really go too big.

But I do agree it's Intake system related.

Which is not unsurprising to me, I knew when I put that manifold on that it wasn't great, but it was the easiest one to do at the time and I knew I could fix it long term by going to ITB's (always the intention).

To be clear it's issues are

• Build quality was shocking, chunks out of the trumpets (which I had to fix)
• Everything was rough as guts
• The runners are HUGE
• Their own thermal gasket they provided actually blocked off the top of the port (yes seriously), so i used the standard honda one.
• It doesn't actually match the head ports perfectly (slightly larger if anything)
• The design of it is clearly more aimed at turbo cars.

The throttle body is 74mm, 

• I don't think that's the issue.
• Although it's worth pointing out just to show how bad Skunk 2 is, that the gasket that comes with it doesn't fit correctly for the IACV port to their own manifold.

The intake filter and pipe

• The filter doesn't really have an internal velocity stack, and I did my best to improve it, but it wasn't a good job.
• The pipe has 2 bends opposite each other, then a 3rd bend after the throttle body for the air to get into the manifold velocity stacks.
• Most Hondas run a significantly longer intake pipe, mine is very short. Length helps the air to build up velocity before encountering obstructions like throttle body, corners etc.

The shitty pod filter velocity stack, bends and shortness of the pipe means the air is moving very slowly and never gets a chance to speed up so by the time it gets to the manifold and with that the runners being larger than they should be, the air never gets the velocity that the high RPM needs to fill the cylinders.

That's my current thinking anyway.

[kpr]

runner diameter being a bit oversized  isn't actually much of an issue.  unless its way oversized.  
length is probably an issue though. 

you can see its doing something weird on the dyno sheet, which is most likely the intake runner length.    looks like its wanting to work at 8500. which makes the dip at 7500.    if the runners were a bit longer (most likely factory length)   so it was tuned for 7800-8000rpm  would  make more power.   its something that can be shuffled with the cam timing to a point also. your tuner probably should have already tried that though.

Ideally get those itb's on and make the intake runners way longer.   nothing off the shelf will get you there either due to fitment issues, or too hard to make. 

 

[Hyperblade]

16 hours ago, kpr said:

runner diameter being a bit oversized  isn't actually much of an issue.  unless its way oversized.  
length is probably an issue though. 

you can see its doing something weird on the dyno sheet, which is most likely the intake runner length.    looks like its wanting to work at 8500. which makes the dip at 7500.    if the runners were a bit longer (most likely factory length)   so it was tuned for 7800-8000rpm  would  make more power.   its something that can be shuffled with the cam timing to a point also. your tuner probably should have already tried that though.
 

Ideally get those itb's on and make the intake runners way longer.   nothing off the shelf will get you there either due to fitment issues, or too hard to make. 

 

I'm pretty sure it's quite a bit larger then than stock, but hard to remember now as haven't had it off in a while.

Dave mentioned the same thing about the uptick at 8500rpm, 

He estimated it's down 10 to 20hp at the top end, compared to what he's tuned before with stock manifolds.

ITB's require a bit of a rewire so due to being electronic and pedal changes so I'll plug away at it all and get it to a stage when I can then bolt them on at the right time and see how they go. But my quick measurements show I need to get them as close to the heads as possible.

Thanks for the feedback by the way, really appreciate it!

[kpr]

If you wanted to try something in the meantime,  you could take the spacers out of the plenum.  Have some thick head flanges cut to space the manifold out at the head end, lengthening the intake runner.   Maybe a couple at 25mm  so can stack them see what works best.  I'm guessing around 50mm would do the trick. Maybe could get them cut from something for some thermal insulation at the same time.  

[Hyperblade]

On 24/02/2023 at 17:57, kpr said:

If you wanted to try something in the meantime,  you could take the spacers out of the plenum.  Have some thick head flanges cut to space the manifold out at the head end, lengthening the intake runner.   Maybe a couple at 25mm  so can stack them see what works best.  I'm guessing around 50mm would do the trick. Maybe could get them cut from something for some thermal insulation at the same time.  

That's actually a really simple idea to increase the length.

But it would affect my bracing underneath and way more then i want to do to it at the moment.

My plan is to 3d print the top half and straighten up the throttle body + intake for the experience in doing that without having to take the whole manifold off and I want to see if it actually does make any difference.

Then I can get stuck into the ITB's which i know will be much better, but are going to take a lot of time playing around with redoing wiring.

[Roman]

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)