Cosworth YB Boost, Power & Torque Limits
Discussion
We have a couple of Cosworth YBs which run in competition and on trackdays. Turbos have 34mm inlet restrictors to conform with stage rally regs. Just like to call on the experience of other YB owners. What level on boost, power and torque do you achieve reliably with a standard engine under fast track conditions? What relatively cheap mods have you made to make YB reliable at higher boost and power? I know there are £30k YB engines available but that's way outside my budget.
For starters we run up to 1.5 bar boost and get between 270 and 300hp (34mm restrictor). Peak torque remains a mystery.
For starters we run up to 1.5 bar boost and get between 270 and 300hp (34mm restrictor). Peak torque remains a mystery.
Does the guide in the front of the Burton Power catalogue help at all?: http://www.burtonpower.com/tuning-guides/tuning-gu...
ETA: if nobody else pipes up here, might find a few more owners over at PassionFord.
ETA: if nobody else pipes up here, might find a few more owners over at PassionFord.
Thanks - we are very familiar with buying parts from Burton Power 
Some YB power claims on PH are amazing - no less than 840hp from just 2.0L
It can be achieved because turbocharging ultimately is "screwdriver tuning" but the engine must be very special to survive. Sensible limits with a standard engine seem to be 350hp, 400Nm on 1.5 bar (36mm restrictor or bigger). Group N pushed to 1.7bar but were not terribly reliable. After that, it all gets very expensive £*****
Interested in the experience of others when a YB is hammered under race track condition (not just a quick blast away from lights).
Some YB power claims on PH are amazing - no less than 840hp from just 2.0L
It can be achieved because turbocharging ultimately is "screwdriver tuning" but the engine must be very special to survive. Sensible limits with a standard engine seem to be 350hp, 400Nm on 1.5 bar (36mm restrictor or bigger). Group N pushed to 1.7bar but were not terribly reliable. After that, it all gets very expensive £*****Interested in the experience of others when a YB is hammered under race track condition (not just a quick blast away from lights).
Ahh, that's cool, wasn't sure they weren't new acquisitions.
Know what you mean though about some of the power claims - even with forged internals one wonders how long they survive (and how driveable they are if it's mostly big turbo doing the work)... and the cost of bits for these if thy do let go isn't trivial.
I'm in a slightly different boat: I run a N/A YB in one of my cars and just debating how far past the stock 6800 one can reliably push for trackdays...
Know what you mean though about some of the power claims - even with forged internals one wonders how long they survive (and how driveable they are if it's mostly big turbo doing the work)... and the cost of bits for these if thy do let go isn't trivial.
I'm in a slightly different boat: I run a N/A YB in one of my cars and just debating how far past the stock 6800 one can reliably push for trackdays...
Wrong forum here mate.
Go to www.Passionford.com
you will find lots of experts and lots of help and experience.
Some basics though as I've run Yb engine for over 12 years in trackcars from 350-605bhp.
Have a 500bhp one in my Westfield at the moment.
A standard engine will run 350bhp-400bhp all day long in my experience. My 605bhp engine was HAMMERED for 10k miles and 4 years never skipped a beat. 70% of those were track miles.
Just make sure its properly mapped. Thats the most important thing.... if not, its just a matter of time until it melts.
Also remember that They are OLD engines now. So many have lots of old ancillaries and wiring and sensors. THESE are what will cost you the engine.
You wont break the crank or rods with anything under 8000rpm and 600bhp...
the 200 block is mega strong as well.
Headgaskets are no problem now at all either.
They are STRONG engines. Std head and cams will do 400bhp on right turbo. Std 2wd and 4wd manifolds are fine.
You dont need to spend much to get good reliable power.
A decent baffled sump or probably gated one is needed really for track work in a proper car.
Go to www.Passionford.com
you will find lots of experts and lots of help and experience.
Some basics though as I've run Yb engine for over 12 years in trackcars from 350-605bhp.
Have a 500bhp one in my Westfield at the moment.
A standard engine will run 350bhp-400bhp all day long in my experience. My 605bhp engine was HAMMERED for 10k miles and 4 years never skipped a beat. 70% of those were track miles.
Just make sure its properly mapped. Thats the most important thing.... if not, its just a matter of time until it melts.
Also remember that They are OLD engines now. So many have lots of old ancillaries and wiring and sensors. THESE are what will cost you the engine.
You wont break the crank or rods with anything under 8000rpm and 600bhp...
the 200 block is mega strong as well.
Headgaskets are no problem now at all either.
They are STRONG engines. Std head and cams will do 400bhp on right turbo. Std 2wd and 4wd manifolds are fine.
You dont need to spend much to get good reliable power.
A decent baffled sump or probably gated one is needed really for track work in a proper car.
Current turbo is hybrid T3/T35 which has overcome the compressor going past the choke line without introducing undue lag. Originally we ran a smaller compressor housing but kept overspeeding turbos.
We have two YB engines with earlier 205 blocks. Configured for stage rallying with mandatory 34mm inlet restrictor, we are running 270 - 300hp (even the best engines only have around 320hp). Both our YBs have been incredibly reliable in competition using up to 7000rpm and 1.5 bar. We will race the car in club series from early 2012.
Agreed later engines with 200 block are stronger, but maybe unecessary depending what regulations allow. Many series have inlet restrictors (eg 34 or 36mm) and boost presure limits (eg 1.3 bar) so power output is limited. What level of boost can you run reliably on the track?
Thanks for the advice on mapping and sensor/wiring reliability. Our map is not optimal so the set-up is intentionally conservative, but sensors/wiring tend to get ignored which is asking for trouble.
We have two YB engines with earlier 205 blocks. Configured for stage rallying with mandatory 34mm inlet restrictor, we are running 270 - 300hp (even the best engines only have around 320hp). Both our YBs have been incredibly reliable in competition using up to 7000rpm and 1.5 bar. We will race the car in club series from early 2012.
Agreed later engines with 200 block are stronger, but maybe unecessary depending what regulations allow. Many series have inlet restrictors (eg 34 or 36mm) and boost presure limits (eg 1.3 bar) so power output is limited. What level of boost can you run reliably on the track?
Thanks for the advice on mapping and sensor/wiring reliability. Our map is not optimal so the set-up is intentionally conservative, but sensors/wiring tend to get ignored which is asking for trouble.
Edited by bigdog3 on Monday 31st October 11:18
You can fairly reliably run upto or over 2 bar of boost of a T3 or T34 if your intercooler/chargecooler is upto keeping charge temps down. Lots of peoples aren't. Water Injection is commonly used on YB's engines that are tracked. Not ideal but a fairly simple solution if you are having ACT issues.
A proper T34 on a .63 housing will just about make 400bhp on a fairly standard engine. The Turbo wont last forever as you are ragging ass of it, engine will be fine though in my opinion.
205 block not ideal for really big power. But some people have used them with no problems. Keep it the right side of 375 ish bhp and it should be no problems at all.
A proper T34 on a .63 housing will just about make 400bhp on a fairly standard engine. The Turbo wont last forever as you are ragging ass of it, engine will be fine though in my opinion.
205 block not ideal for really big power. But some people have used them with no problems. Keep it the right side of 375 ish bhp and it should be no problems at all.
double post. Sorry!
P.S I've never run any kind of restrictor so have no real knowledge of them.
Put a post on Passionford. Lots of experts and people that may race in your series plus the top YB builders like Reyland, MAdevelopments, MSD, SCS, Turbosystems all use the board.
P.S I've never run any kind of restrictor so have no real knowledge of them.
Put a post on Passionford. Lots of experts and people that may race in your series plus the top YB builders like Reyland, MAdevelopments, MSD, SCS, Turbosystems all use the board.
Edited by Porkie on Monday 31st October 15:16
Edited by Porkie on Monday 31st October 15:25
Thanks for the advice - I'll post the question on PassionFord. Inlet restrictors in competition are a necessary evil but they have a nasty side effect. For the same compressor and housing, fitting a restrictor pulls the choke line back along the mass flow axis, so the point when turbo speed goes exponential occurs earlier. Failure mode is usually turbine blades disappearing down the exhaust system but I would hate a compressor wheel to disintegrate 
Porkie said:
what series you racing it in?
Cossie Whaletail is a log booked MSA tarmac rally car so it's only eligible for Thunder Saloons, or series which accommodate them. That was the basis on my question - with minimal expenditure and after removing the inlet restrictor, what level of boost, power and torque can we run reliably? You've answered that already and PassionFord should add more.Situation is more complex because we have two other competition cars (one has YB engine). Cossie Whaletail is an interim solution until the first has been satisfactorily developed. Fortunately opportunities to race in several saloon series are opening. We've been fairly busy competing in 2010 and 2011 but should get even busier in 2012
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