Ke70 - Turbocharged 3K Build - Now Ke30 Coupe

[RO78IN]

Ok, so the project really is in its infancy and to be honest, will probably take a shite load of time to complete, but here goes anyway.

 

Firstly, the most burning question is going to be WHY THE f@ck would i go 3K??? Simple. Cams put a 1.7 capacity factor on for anything super /turbo charged and i wannted something Turbocharged (as one of our company divisions works with turbos) and wanted to run somewhat cheaply, hence i wanted to be in the under 2L class.

 

So backwards configuring, 2000 / 1.7 = 1176cc, so the capacity of the 3k at 1165 is as close to perfect as you could want.

 

Further to this, some people may know, that from a certain Cubic capacity, you're really only going to get so much torque, so revs are the answer. and the Stroke / bore ratio lends itself to high revs!

 

So the game plan is to have a 3K, 10,000 + RPM engine, arround 1.5-2 bar boost and then to see how long it lasts! Boost will be dialled in very slowly, and if i have to stop around 1 bar, i won't be too upset.

 

main reason for doing this is as much an engineering experiment as anything else. It will be fun in the hill climbs tho! also, I'm looking for an old rolling shell for possibly a race car to potential put this thing in, but in the mean time, its going in a Streeter (not that the engine will be very fun on the street...)

 

So far, i have:

- a full 3k engine with everything...

- a massivly over worked 5K head with Gemini Valves and all sorts of carzy shit done (which needs a fair amount of clean up)

- H Beam 4AGE Con-rods

- Suzuki GXS-R1100 Piston set (20mm pins to suit above)

>as an aside, these pistons look pretty well suited to this application though. it was quite surprising. Although the compression height is not that close, it was the way i needed it as the head had so much shaved off it, it was near impossibly to get the CR down below 14.5:1 LOL. Someone had big plans indeed!!!!

- Fuel wise, i have some carbies in the shed, so I'm TRYING that route first. I have a pair of side draft dellortos, and a weber 32/36. I think i'll try the weber first though...

 

thats about it at the moment. i have about 5 pages of maths that i have ran through to get the engine parts listed above, which if you would like to know, i can put up here. Some interesting things all worked out nicely like the Conrod / stroke ratio being nicely infavor of high RPM. Stroke and Bore = in favor of high RPM and so on.

 

I am trying to get the actual car Bluesliped at the moment, so if anyone knows anyone south of Sydney, please let me know - i live in wollongong.

 

i'll post some photos of the car later on.

thanks

Matt

Edited September 23, 2012 by RO78IN

[Taz_Rx]

Sounds very interesting!

 

Put any thought into turbo selection yet?

[altezzaclub]

Sounds great! Have a chat to filfrederick about building his 9000rpm twincam 4K, I'm astounded at what the bottem end can take.

 

http://www.rollaclub.com/board/topic/51097-4k-twin-cam/

 

I assume you're using solid pushrods in the 5K head. Did the maths indicate massive ports, or is that head just for the valve size?

 

It will be hard to cover such a wide rev range, but if you're in the game I'm sure you can access the right turbo. No chance of an asymmetric pair where the small one boosts low down then a bigger turbo takes over?

[Taz_Rx]

decent sized single will outperform any twin setup these days altezza.

I think this will be more of a matter of "tuning" A/R ratios to suit the rev range.

[RO78IN]

To be honest, most major thing I'm worried about at present is the width of the power curve and finding a suitable close ratio gear box to suit (for a reasonable price is an important stipulator here!)

 

Our work overhauls large frame turbos, so balancing the rotating assembly is no dramas. the rods purchased quoted 10K rpm in a 4AGE with a much longer stroke and smaller Rod / Stroke ratio with heavier pistons, so everything is in my favor that way.

 

THe 5k head was already done by someone else, but by my measurements last night, the valves come about 1.5-2mm from touching (so when its hot, I'm a little concerned about valve sealing, but anyway). but the funniest thing is they are so large that its only JUST going to fit inside the bore!

 

i was playing around with the thought of a supercharger as well given the head configuration, however i work with turbos, so really, i should use them!

 

I haven't done too much with the turbo calculations yet, as to be honest I'm not really sure what to expect in terms of HP and whatever. I'm really keen on having enough power to be competetive in under 2L super (or Sports) Sedans. to that end, anyone know of a Rolling shell (preferably log booked) available?

[kickn5k]

Sounds very interesting!

 

Put any thought into turbo selection yet?

+1 from me too. I'm very interested!!

 

Can you post a pic of the gsxr piston?

[RO78IN]

OK,

So Turbo Selection looks like this -

for 300HP @ 10,500 RPM

- Airflow requirement is 33.3LBS or 483 CFM.

- Boost requirement is 25 PSI or 2.68 Pressure Ratio

 

Based on Compressor maps, the best turbo is a TD04 - 19T. Surprising hey!?!?!

 

- Boost is expected to come on around 6500rpm giving 4000RPM of 'usable' torque curve. (sounds stupid having something Starting to boost at 6.5K, but when the redline is so high, its the 'best'). in terms of Pure HP, the TD05-16G was the better option up top, however i think in the interests of 'area under the curve' in terms of the workable power band, this is the best solution.

 

I think it might be worth next looking into gearboxes to see what the spread is between curves, because unless it can keep within the 4000RPM, iits going to be dropping off boost between shifts.

 

ANyway, have alook at the plotted points on the graph. first dot is Idle, second (still a ways of the curve is 6K), second line half way in is 7000, the rest are 8000, 8000 with different temp, 9250 and 10500

 

Ok, Photo will be in next post once it comes through...

[RO78IN]

[ke70dave]

Fantastic to see some turbo maths here.

 

td04-19t, thats a factory wrx turbo yeah?

[RO78IN]

TD04 -15T i think was the Standard one. They are actually quite plentiful as the 'upgrade' to the WRX (read hiflo version). I think i might actually just by a cheaper version out of KendoDynamic or something first just to see. Its going to be fairly peaky engine, and i may need to reconsider the RPM limit if i cannot pull it off.

 

One thing is becoming clear, its going to need a short Diff Ratio and a reasonably close gearbox. Anyway, can worrry about that in time. Need to get it together and see if it stays together first!!!

[RO78IN]

Can someone answer how many RPM they are doing in 4th at 100K? (in a KE70 that is) thanks

[altezzaclub]

Depends on the diff- 4.3 for auto (which we still run even with a K50) and 4.1 in a manual.

 

I'd expect 3300rpm at 100kph in 5th with a 4.3 (too many anyway!!) Then again, I had 14" tyres on...

 

 

nope- more than that! Play with this

 

http://vexer.com/aut...-rpm-calculator

Edited September 13, 2012 by altezzaclub

[RO78IN]

Thanks;

Thats all i needed to know. I'm trying to work out theorhetical (spelling! - sorry) Top speed of the set up or moving to a 5 speed gearbox with a 1.0 5th gear... That and matching it with a diff ratio, but with 10.5Krpm limit, l should be able to lift the diff ratio something more like 4.6:1...

 

Target is 210KPH. i don't think that at eastern creek i'd ever get more than that anyway (not with 300HP) so i may as well gear it down as much as possible so I'm redlining somewhere nearer the end.

[ninja-philbo]

U won't make 300hp with a 3k. head won't flow it.

[altezzaclub]

U won't make 300hp with a 3k. head won't flow it.

 

Well, does 15psi boost flow twice the air that an NA motor sucks?? If atmosperic pressure is 15psi then I assume 15psi boost is 30psi absolute.

 

 

If you had a 150bhp NA race motor, does double the pressure behind the air double the power? I suppose you need to look back in the days when they ran turbo 1500cc in Formulae One. BRM got 600bhp from their 1600cc, although I don't think its very comparable!

 

 

http://en.wikipedia.org/wiki/British_Racing_Motors_V16

 

In Raymond Mays' book^[6], he claimed the following power curve with the 4.0:1 supercharger (5.7 ata):

• 100 bhp (75 kW) at 5,000 rpm
  
• 175 bhp (130 kW) at 6,000 rpm
  
• 250 bhp (190 kW) at 7,000 rpm
  
• 335 bhp (250 kW) at 8,000 rpm
  
• 412 bhp (307 kW) at 9,000 rpm
  
• 525 bhp (391 kW) at 10,000 rpm
  
• 585 bhp (436 kW) at 11,000 rpm
  
• 600 bhp (450 kW) at 12,000 rpm
  

He also stated that at Albi 1953, Fangio's V16 had 72 psi boost (4.9 ata) and 585 bhp (436 kW) @ 11,800 rpm, and he reached over 190 mph (306 km/h).

 

...and Nick Mason from Pink Floyd had one.... Just imagine listening to that sound any time you liked!