Hyperblade's KP61R - Toyota Starlet with Honda K20a

[Hyperblade]

Knowing i'm not making the start of this club season, one of the other TODO items was sorting out the cooling system.

I currently run a custom radiator, which has brackets to sit it at an angle and attachments points for ducting, it was created for the BEAMS engine so that I could duct it out of the bonnet (space was tight). 

Naturally I cracked it as well with all the vibrations (yes it was rubber mounted) 🙄 fixing it required a recore, but when it came back it was not quite the same in terms of fitment which made fitting the ducting back on it a pain.

I also have an issue with Oil temps being to high, while I run an oil cooler, I don't thinking the ducting is quite right for it and I want to tidy it's mounting up.

I also have more space now in front of the engine.

So I've been on the hunt for a factory radiator that I could replace it with, this is a bit challenging as I wanted something that fitted in the space, ideally had both outlets on the left hand side (which means end tanks rather then top and bottom), and was fairly common so cheaper and easily replaced, 32mm inlet/outlet also a bonus, also must be full aluminum option.

Trying to see what was out there was challenging so In the end I got AI to produce a powershell script to download all of Fenix Radiator's catalogue as a json file, I then got AI to take that file and run a local HTML page to allow me to search by width/height of the radiators and then show name, pricing and link to the radiator. This actually worked fairly well, with the natural issues of Fenix changing the order of dimensions on their product pages, but it allowed me to quickly eliminate a wide range of common radiators that were just too big.

This worked great at telling me that nothing common here really fitted 🙃. the one closest was a later model (SW20) MR2 radiator, but was just to big, however the earlier model MR2 radiator potentially could have worked, but was less common. Both had inlet/outlet on either side of the radiator, which was doable but means more piping.
 

Then i trawled through trademe, and found the VW Golf Mk2 GTI 1.8 Radiator (there are 2 variants and only appear to differ in width, I went with the wider one) might work.

Upside down...

$250 delivered to my door in 4 days from Aus (with 2 brand new fans) for a full aluminum radiator was worth the risk (At that price i can buy a second as an onhand spare...).

Pros

• No radiator cap
• Inlet/outlet on the same side and correct size for my pipes.
• Fairly common overseas (less so in NZ but still can get it here)
• Full aluminum
• Claimed 40% better cooling over the stock one. 
  • So I think cooling capacity will be fine for my 2L as it will be ducted so when moving it they end up being efficient and when in pits your only idling anyway.
• Has mounting points on both side which i can build my ducting off/oil cooler mounting.
• Has an extra m22x1.5 port that could be potentially used for a filler.
  • Have an issue with oil cooler covering it though.

Cons

• Running upside down means the breather/bleed port is bottom left now (will just block it up)
• Need to find a way to get water into it.
  • Appears there are hose inline radiator caps you can get.
• Bleeding it
  • Although didn't have to do that with previous radiator so may be fine

 

I wasn't happy with the old positioning of the oil cooler and I want to make things simpler from a packaging point of view, so I want to mount the oil cooler behind the radiator (should help heat oil up too when sitting there)

 

 

So currently working on getting it mounted in the car, then will work out oil cooler mounting, and then all the associated hoses.

[Hyperblade]

So I decided to rebuild the cooling system in CAD as I'm going to need it for the ducting and it will make life easier.

This is the current plan.

With the oil cooler facing down it makes the hose routing much easier, and shorter. Centering it also means the brackets are easier. 

And that leaves the spare M22x1.5 port for a radiator filler which is much nicer then inline.

Then that only really one place to put the fan. Being on top won't be a bad thing as it will cool the oil cooler when on too (only on sitting in the pits).

Yes will be 3d printing a shroud extension for it to close it into the radiator.

In terms of what the bracket will be made of, haven't finalized that yet, but contemplating metal 3d printing just so I know it's not going anywhere, but would be roughly $205 USD for both in Stainless 316, (that's before optimizing it to remove material).

With having done it in CAD, it is now easy to change it to mount a larger oil cooler, or fan if required in the future.

 

[Hyperblade]

So multiple things on the go at the same time

I've done some research into options for the ITB's and the following is the conclusion.

Honda K20a = 94mm Bore spacing.

BMW S1000RR 

• $400 NZD
• 48mm Plate
• 80 mm bore spacing (Not ideal)
• 3D Print Manifold
• Reuse Fuel Rail
• Reuse Current Injectors
• 3D Print Trumpets
• Electronic Standard
• Has outboard injectors.

Pros: Really light. I have them already, I have the outboard injectors, Full CAD Model might be available from Prototipo. Electronic control as standard. Proven to work well by Dave.
Cons: Bore spacing not perfect, could be slightly larger. Need to bore the back side of them out slightly larger (can be done without affecting plate)

BMW S65 ITB 

• $650-$730 NZD
• 50mm Plate
• 98mm Bore Spacing (But I believe they can be moved on rail to suit what I need).
• 3D Print Manifold
• Reuse Fuel Rail
• Reuse Current Injectors
• 3D Print Trumpets
• Electronic Control Extra $ (Definitely don't want BMW one)

Pros: Bore spacing adjustable, slightly larger in size.
Cons: While they normally have standard electronic control that price is just for the ITBs so have to buy electronic motor.

Aliexpress OBX Individual Throttle Body

• $640 NZD ($160nzd each)
• 48mm or 50mm Plate
• Custom Bore spacing
• 3D Print Manifold
• Reuse Fuel Rail
• Reuse Current Injectors
• 3D Print Trumpets
• Electronic Control Extra $

Pros: Cheaper than EFI Hardware.
Cons: Have to work out linking them together, unknown quality, have to buy electronic motor.

EFI Hardware 

• $1200 AUD just for throttle bodies.
• Any Plate Size I want.
• 94mm Bore Spacing
• 3D Print Manifold
• Reuse Fuel Rail
• Reuse Current Injectors
• 3D Print Trumpets
• Electronic Control Extra $

Pros: Will be quality item, come in linked pairs so only need to one join.
Cons: Price, have to buy electronic motor.

Jenvey K20 Kit

• $4000 NZD
• 48mm Plate (options for 50-51mm)
• 94mm Bore Spacing
• Includes Manifold
• Includes fuel Rail
• Need new Injectors to suit
• Includes Trumpets
• Electronic Control Extra $

Pros: Known setup that has been tested against many other brands and has consistently bet them all.
Cons: Price, need to buy new injectors, have to buy electronic motor.