Hyperblade's KP61R - Toyota Starlet with Honda K20a

[Hyperblade]

So what everyone has actually being waiting for, the final comparison between Toyota Altezza RS200 3SGE BEAMS and a Honda Accord Euro R K20a engine in the same chassis

Still trying to get my hands on a single dyno sheet with the 2 different engines on it. So this will have to do.

Modifications/Setup

Toyota Altezza RS200 3SGE:

• 120,000 k's
• SQ Engineering Quad Throttle adapter plate
• 4AGE Blacktop throttles
• 70mm trumpets
• Combined Piper Cross Filter
• Stock Injectors
• SQ Engineering Slim line alternator (smaller Echo alternator)
• No Power Steering pump or AC
• Custom header (TRD Copy) to side exit exhaust 2.5" Adrenaline R muffler
• Link G4+ Storm (Blue)
• Engine internally stock
• Lightened flywheel
• HD Exedy Clutch
• J160 Gearbox
• 3" Driveshaft with sliding yoke into gearbox

Oil: Castrol 5w40 
Rev Limit: 8000rpm
Dynoed in 5th gear 1:1.

Honda Accord Euro R K20a:

• 108,000 k's
• Skunk 2 Ultra Street Intake Manifold
• 770cc FIC injectors
• Skunk 2 74mm Throttle Body.
• 3" intake pipe from pod filter.
• Custom header to side exit exhaust 2.5" Adrenaline R muffler
• Stock water pump replaced with EWP
• Alternator replaced with smaller Honda D15 one.
• No Power Steering pump or AC
• Stock Oil Pump and Balance Shafts replaced with ported Type S oil pump.
• New Timing chain
• Lightened flywheel
• HD Exedy Clutch
• Link G4X XtremeX
• Honda S2000 AP1 Gearbox
• 3" Driveshaft with sliding yoke built into shaft as gearbox has flange
• VTEC 4500rpm

Oil: Castrol 5w40 
Rev Limit: 9000rpm
Dynoed in 5th Gear 1: 0.94076

Same:

• Tires 54cm Michelin Slicks at 21 PSI, on same Rims
• Same AE86 Diff (Brakes were changed from stock to AP with knock back) 4.5555 Crown wheel and Pinion.
• Same Dyno

Different:
Dyno retarders have changed from 110v to 220v.

 

Results
3SGE :
201hp @7250rpm
173.6 lbft @5150rpm

K20a:
206HP @8250rpm
167.9lbft @5300rpm

Thoughts
I'm a little bit disappointed in final figure, but I think my expectations were to high.

You have to take all the HP figures that everyone posts with a grain of salt. 
Especially anything from the UK who like to give made up flywheel figures when they dyno there cars on a rolling road...

Changing from a front wheel drive to rear wheel drive setup definitely has more drivetrain loss, from what I've read a factory stock S2000 AP1 with 240/250hp at the flywheel dynos 200hp at the wheels.

Also a lot of people show "stock internals" figures which include changing cams etc.

So the power figure is in the right ballpark really for the modifications (stock K20a has 220ps at flywheel) as rear wheel drive.

Looking at some of the NZ figures I have seen, the engine would probably get quite a gain (20 to 30hp) from a set of drop in cams (no other valve train changes)

But if you ignore the single figure and look at the dyno sheet it pretty much makes 200hp from 6700 rpm all the way to 8700 rpm which is a very significant power band.

So overall, it's a good improvement.

 

Shakedown
So I then got it out to the track and managed 4 laps before the gearbox lost most of it's oil when a bolt came loose. Luckily I was going fairly slowly so no internal damage done hopefully.

However a bigger issue is a massive driveline vibration.

Plan A: Driveshaft is getting balanced at 5000 rpm (it does 9500 rpm in 6th)
Plan B: CV Front joint on the same shaft, or a replacement driveshaft.

Driveshaft is to short to go 2 piece and we think the angle of the engine and gearbox is impacting the universal joints. However aftermarket CV joints for these are supposedly not very good. So currently looking at options.

Car definitely felt like it was pulling really hard, but with so few laps, and me just making sure everything was working, not a good indication of final result.

 

Videos:

First 2 Laps:

 

 

Second 2 Laps (where it dropped the oil):

Flyby (Potato Cam):

 

 

[Hyperblade]

Some progress has been made.

Driveshaft was sent up north to be balanced at a higher speed and the UJ's were tightened.

And so had it out for another shakedown at a local sprint day.

First race just took it easy checking things over (pretty boring video, best to skip).

 

 

Second race, gave it full beans off the line against an EG civic with K24 and 300hp at the wheels, he got a bad start...

 

 

Third race on slicks and it started drizzling, but overtook a Porsche and a Lotus...

 

 

The driveshaft was a lot better, enough for me to push it a lot harder in those videos.
But there was still a vibration there that won't be good for components, best guess is it's the angle of the engine/gearbox in the car, front of engine angled to left to clear headers and for weight distribution which means the UJ's are not in sync.

Those videos also have me mucking around a lot with the brake bias as that's been all reset, along with suspension changes affecting rear of the car during braking so still getting it dialed in (sprint day you don't get many laps).

Other thoughts, is the S2000 Gearbox throw is as short as the J160 with a short shift kit, if not shorter, it's a great feeling box.

Also you may have noticed in my older videos I didn't heel and toe, originally that was because it was impossible to with the stock pedal setup and my seating position, 
but since I have the new pedal box and seat I really needed to learn, so with the minimal seat time I've been trying to get used to it, still a work in progress as you can see in the videos.

So the shake down highlighted a few issues.

• Driveline Vibration still there
• What we believe is heat soak of the oil temp sensor as it hit 123 degrees, and there should be no way the oil hits that when it struggled to get over 80 on dyno (with some of my bonnet ducting removed which allowed a breeze over the sensor).
• Getting car up to temp with the EWP is a pain, it's not quite right at the moment. Was setup on dyno perfectly, but the real world has a lot more airflow over radiator.

So before Christmas I shopped around for a driveshaft with a CV on the front, basically came down to only one place who were prepared/could make it to handle 9500rpm.

Hence a new Carbon fibre driveshaft arrived last week from the Drive Shaft Shop out of the US, i'll be honest I was very hesitant in ordering from them as I had been forewarned by a couple of people about their quality and after sales support.
But I had no other options. I can say their pre sales service was good with prompt communication and fast building of it and shipping. 

It still needs to be fitted into the car, we are just making up a flange that goes over the existing AE86 Diff flange (from the diff side) to better spread the load from the new driveshafts rear Hilux UJ which has a bigger bolt pattern.

Here's the difference between Hilux and AE86 diff flanges.

Heat soak of the oil temp sensor should hopefully be solved by some new shield i created.

The EWP control is a bit if a pain, the duty cycle is controlled by RPM vs ECT. 
Which is great but i feel it misses another key input which is the speed of the car which affects the car's ability to get rid of heat.

So it feels like half the solution to the problem.

You can see the duty cycle all over the place here and the pump is barely breaking a sweat (and that's with half my radiator ducting closed off).

For the EWP I made up (by hand, no lathe...) a reducer to drop the coolant pipe size down from 30mm to 18mm to slow the water, it goes into the return feed on the radiator after the water goes through the engine.

I'm hoping that means I can use more duty cycle in the pump, so give a wider duty cycle range to play with.

I've then tweaked the table handling the ewp to try and get it to be more flexible in it's ramp up/down by letting the ECU interpolate in between the cells more, feel free to let me know if this is a stupid idea...

Old: 

New:

So once diff flange is done, will aim to get it back out for another shakedown to see if we have finally solved the vibration and see how we are going with ECT.

 

Discussion here: 

 

[Hyperblade]

Flange has been done, and will get fitted this week.

I can run the current driveshaft I have or the new one. Just press fits over existing flange.

Original flange probably would have been fine with the forces involved and the fact it would have mainly been a clamping force. But I decided it's just not worth running the risk considering the catastrophic consequences that could occur.

Come up great.

So it turns out 0.5mm aluminum wont withstand 200km+ who would have guessed, I am surprised it actually survived a few laps.

I had strengthened the bottom edge, but ran out of material before I could do the rest and got the car on track.

Repaired version, with nice rounded edges for the airflow (not that I need any extra, keeping the car in the temperature zone is actually the biggest issue).

Painted and it fits in nicely (ignore raw unpainted panel below, at some point will get splitter off and paint that, but not a priority).

Sharp eyes will notice the grill is open, once car is fully shaken down and working how i want, then I will blank that off and feed cold air into the intake from the left headlight.

Very long term It would be nice to have a fibreglass/carbon piece that replaces the grill, headlights and side lights as one piece, then put a vinyl photo on it to make it look normal. would save a couple of kg and be a lot more aerodynamic.

[Hyperblade]

On 09/02/2022 at 20:17, Hyperblade said:

So before Christmas I shopped around for a driveshaft with a CV on the front, basically came down to only one place who were prepared/could make it to handle 9500rpm.

Hence a new Carbon fibre driveshaft arrived last week from the Drive Shaft Shop out of the US, i'll be honest I was very hesitant in ordering from them as I had been forewarned by a couple of people about their quality and after sales support.
But I had no other options. I can say their pre sales service was good with prompt communication and fast building of it and shipping. 

 

So...

Diff flange was all fitted up and the driveshaft was fitted and then checked against the instructions from The Driveshaft Shop, and it was too short...

It was extended as far as it could go so could not thrust out if required.

To say I was disappointed would be an understatement. I had even double checked the measurements on the quote via email before ordering and asked if it took into account the thrusting and they said yes...

When building a driveshaft it's a fundamental measurement, to fuck that up time and time again as I had been pre warned shows that they don't have the process and checks and balances in place to ensure the consistent quality of their products.

 

I contacted the original salesman and he was very responsive, he got me to take measurements with driveshaft in place and quickly had a spacer for the rear diff made and shipped out to me at their cost. (luckily the driveshaft was short, if it was to long that would be an interesting discussion...)

 

Once I had the spacer I made up the heat shielding for the front of the driveshaft, the carbon shaft has warnings on how hot it is allowed to get, and also I want to protect the CV joint from getting exposed to to much heat to prolong it's life.

 

I have a new speed sensor on the way as my one is behaving really weird (cutting off the signal at 5000hz), hoping that solves the problem.

Next step is get the car out on track again for a shakedown to see if I've improved the way the cooling works and fingers crossed the driveshaft solves the vibration issues.
 

 

 

[Hyperblade]

So had the car out to a track day with the new driveshaft and I can finally say the vibration issue is solved.

So that's a massive win.

Here's some footage (track day so no passing allowed on corners)

 

 

 

Car Handling 
Car handling is taking a bit of getting used to, traditionally when i was mid corner and I put the power down it would want to oversteer. When you get on the power now it actually get's more grip in the rear but also turns in more, which is a very unusual feeling to get used to. But a positive one that I need to adapt to.

I ran a 1:36.500 without going crazy on 4 year old tyres and 15 degree day (with only one clear lap), which is down to what I was doing before, so that's nice to finally get back to that. Next target is PB of 1:35.800.

 

Water temperature

Water temperature is still an issue however, just hard to get it up to temp quickly. Which won't work for one warm up lap then standing start race.

I've been trying to avoid putting in a thermostat as there isn't a lot of room and it's a clean simple setup at the moment (the stock setup is long gone as it weighed 5kg and was in the way of the engine mount)

So I finally bit the bullet and after 2 weeks of mucking around with stores in the UK finally managed to convince someone to take my money and ship one out to me.

I got the smallest I could find, it takes a classic mini thermostat (82c). I've drilled a 2.5mm hole in the thermostat to keep water circulating through at a reasonable speed.

 

 

Space is very tight to fit it in and I didn't want to muck around putting it under the intake manifold as it would make it a real pain to service if needed.

I only just managed to fit it at the top inlet on the radiator with some gentle persuasion of the oil cooler ducting, not pretty but it works.

 

 

EWP Setup
So my original EWP setup (by the tuner) was a running the water pump at Frequency of 0.6Hz (we will come back to this) and I had been changing the table to try and get it to find a happy medium by itself, so between 80 and 92 degrees letting it scale up as required. 

 

This just wasn't working (without thermostat), and I was concerned with the frequency what impact that would have on the pump life as it was basically stopping and starting it 0.6 times a second, which didn't seem like a good idea (but I'm not an expert in this area).

So I sent support email to Davies Craig (who make the water pump) for advise on its limits as I was a little concerned by how it had been setup by the tuning shop.

Their support staff rung me and spent over 45 mins on the phone to me going through the possible causes and solutions. That's amazing service for just a simple water pump.

They said the pump should be fine for my setup (I was thinking it was overkill) and that they hated restrictors and didn't recommend them due to it restricting the max flow of the pump.

The best guess was that the radiator was super cooling the water, so when running through the engine it was to cold and so never allowed the engine to get to the right temp, and then when flow increased it dumped a lot of cold water into the engine block, detected it was cold then slowed the pump again.

Basically the pump was running too slowly (which seems exactly like what you want when your trying to get the car up to temp).

They also confirmed running it at 0.6hz was a bad idea, after some discussion on the pros and cons of higher vs lower frequency (higher = less noise on the circuit) we went with 100hz.

And a completely different table.

 

The idea is the thermostat always has steady stream of water flowing over it through the 2.5mm hole so it's bulb will always be reacting fast to the water temp, it allows the whole circuit to heat up and also means the water is flowing through the block faster so means more consistent readings at the ECT sensor and spends less time in the radiator.

So up to 82 degrees the thermostat controls that flow, as soon as it goes over that the thermostat starts opening and allowing more flow so so should self manage it, the EWP is then set to max out it's flow as we get closer to 100 degrees, so should eventually settle at a happy medium.

Testing on jack stands shows quite a different characteristics in how it gets up to temp and holds it, so I'm cautiously optimistic we might have solved the issue (bar minor tweaking).

But on track is vastly different in terms of air flow, so need to get it out for another shakedown.

Racing starts 14th August, so need it all sorted by then.