300bhp N/A B20


lazybean

lazybean

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Apr 28, 2010
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Disregarding all costs and whether it's a good idea or not. Would it be possible to build as a daily drive? Would it even be possible to build? I'm just asking the question out of interest :)
 
A good idea? It depends what you classify as a good idea? How do you intend to extract 300 horses from a B20 NA - I am keen to know!
 
Possible? Possibly. By my workings you'd need to make 173lbft at 9100rpm to make 300bhp. It's possible to make 173lbft out of a B20, it's possible to push 9100rpm too, but doing both at the same time is going to be hard. You could do it with less torque and more revs, or visa versa, but 173lbft and 9100rpm are well and truly on the limits.

If you were to do it, you're talking BTCC levels of engine building. Infact, it's not even building, it's going to require proper engine design, with custom made well, everything really.
 
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It's just a number lol... why do people get so caught up in dyno figures?
 
Rich777 said:
It's just a number lol... why do people get so caught up in dyno figures?
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I think it's an interesting question. I don't get hung up on dyno figures, if/when I get round to actually tuning an engine instead of just buying more powerful ones, I would be making sure it was giving everything it could in terms of RPM and BMEP. That's effectively what a 300bhp B20 is doing.

173lbft is 216psi BMEP, as good as most F1 engines. 9100rpm is a piston speed of over 26m/s, that's also higher than most F1 engines manage IIRC.

It would take a **** hot engine designer to build one.
 
So in formula 1 engines they tend to have really big bores and small strokes. What is the advantage of this?

And maybe a better question to ask is, using all of the best aftermarket components how powerful could you make a N/A B20?
 
Doubt just using top aftermarket stuff is the issue. It's more about the building and designing of the engine. Likes of head porting, block strengthening and balancing.

Im sure someone quoted a 270ish whip b20 built by endyn I think.
 
lazybean said:
So in formula 1 engines they tend to have really big bores and small strokes. What is the advantage of this?
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The advantage is that they can spin really fast as that is the key to making power from a small, lightweight engine. Despite spinning at 18,000 a typical 40mm stroke in an F1 engine will mean piston speeds are around 23m/s, about what a standard B18C will be doing at 8200rpm.

You'll find most engines are limited to around 25m/s maximum, certainly if they're going to last any amount of time.

Honda made some 300+ out of the old 2000cc supertouring Accords, but that was with a reversed head so the intake trumpets could be positively charged at high speed.
 
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So Honda built a production engine, that moves at speeds comparable to that of a 2012 formula 1 engine. That's amazing. While just doing some reading I just discovered that formula 1 engines and banned from using any variable valve timing!

So Kozy if you increase the max rpm of the engine will it actually increase the power produced?
 
Yes, but you also need to maintain the torque with the increase RPM. The torque is dropping at the the redline on a standard engine, faster than the RPM is increasing so the power output is not increasing. If you increased RPM on a standard engine you would go slower.
 
KieranEG6 said:
Doubt just using top aftermarket stuff is the issue. It's more about the building and designing of the engine. Likes of head porting, block strengthening and balancing.

Im sure someone quoted a 270ish whip b20 built by endyn I think.
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I agree - however it is probably is possible to make 300whp using off the shelf parts - CNC ported head - wild job on the valves & combustion chamber, 98mm crower crank, 86mm darton sleeves, wild roller cams, ITB's- i'm sure you'd be on your way to 300whp, but you'd exceed 2000cc
 
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lazybean said:
So then how would you maintain or increase the torque?
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That's all in the rest of the engine design, you need to make it breathe well at higher speeds so that's all in intake, head, cam and exhaust design, amongst many finer details. Everything you do will reduce low speed driveability too.

A 300bhp B20 would not be a streetable engine.
 
Here's a few quick calculations to find the practical limits of an engine setup, all you need to know is capacity and the stroke.

Torque = 88*Capacity (litres)
RPM = (24/(2*(Stroke (mm)/1000)))*60
Power = (Torque * RPM)/5252

So for a 2 litre with an 89mm stroke, thats 175lbft @ 8090rpm making 270bhp. Anyone that says they make more than this is a liar.
 
I guess it would get to the point where you are practically designing a new engine and no longer upgrading the old one lol. It's all really interesting though.
 
One of my mates has the most powerful N/A B20 at 268 hp, now being broken :(

Race port and polished b16 head
Supertech ti springs/retainers
Supertech Flat face race valves
Buddyclub Spec4 cams
B20b block
Balanced and lightened b20 crank
Balanced b20 rods
RS machine 84.5 pistons
RC 310 injectors
ARP headstuds and nuts
Blackworks Vtec oil kit
Hytech tri-y header 2.5 big bore
Magnecore HT leads
Solid Fabrications Custom 3" exhaust system with j's style back box
Skunk2 inlet manifold
BuddyClub cam pulleys
B&M FPR
Blox 68mm TB
AEM V2 cold air intake
Velocity stack
F1 lightened flywheel
F1 Stage 3 clutch
S80 4.7 LSD gearbox
Cooling plate
Innovative billet mounts
 
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Surely the amount of money and engineering needed would make the K20 a better alternative?

I know the question was B20, but lets be realistic, a 300bhp B20 will not be a "daily driver"
 
interesting thread!

kozy, where does your knowledge come from?! :p your career or just a love for cars? your posts are always a good read
 
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