Andy at Scoobyclinic has knackered my car
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It is late so I'll keep it short and sweet 
OK, if you want to be pedantic, they WILL rev that high but it's not wise. You could ask yourself why Subaru chose to set the rev limiter below 7K on the "normal" 2.5s and below 8K on the 2.5 STis....
So would Dave's but if you look at the graph you'll understand why we don't. No point in revving the butt off an engine if you don't have to! Rev limiter is set to 7K, and we don't bounce cars off the limiter on the dyno.
Why not ? Extrapolating experience of 2 litre motors to 2.5s won't work, they behave differently and need to be tuned differently. Why sacrifice torque to get a little bit more power at the top when there's no more air available up there anyway ?
We wanted to build a quick road car, not a dyno queen. This car maintains 90% or more of peak power from 4300RPM to 6800RPM. This permits the car to be driven permanently in the 90% window. If you change at 6500RPM and say you have a 0.72 ratio between cogs, you will end up at 4680RPM after the shift, at around 428BHP....
That's based on a number of assumptions which may or may not be true. The cam timing chosen is suitable for midrange torque, so the VE falls off rapidly at the top end. The only way to get the air into the engine to push the power peak up in the rev range is to force it in by raising the boost. What if the turbine mass flow rate has already been achieved ? The only way to deliver the extra power to the compressor to raise the boost is to raise the EGBP, but in doing so you make the VE even worse.
As it stands, we have achieved the power and torque without needing to rev the engine to dizzy RPMs. This is not a race car or a dyno queen, it's a road car. The power band is very flexible, if you're in a hurry you can hold it at over 90% power all the time. Again without revving the thing like mad. What's "wrong" with that ?
Cheers,
Pat.
Originally Posted by John Stevenson
that statment is cack !!!
Originally Posted by John Stevenson
Mine revs to 8K
Originally Posted by harvey
Peak power at 5,300 rpm. ? This seems very unlikely ?
Originally Posted by harvey
Any explanation ?
Originally Posted by Bob Rawle
Peak power "ought" to be between 6000 and 6500 rpm even on a 2.5
As it stands, we have achieved the power and torque without needing to rev the engine to dizzy RPMs. This is not a race car or a dyno queen, it's a road car. The power band is very flexible, if you're in a hurry you can hold it at over 90% power all the time. Again without revving the thing like mad. What's "wrong" with that ?
Cheers,
Pat.
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Joined: Sep 2001
Posts: 9,465
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From: The Cheshire end of the emasculated Cat & Fiddle
It is late so I'll keep it short and sweet
OK, if you want to be pedantic, they WILL rev that high but it's not wise. You could ask yourself why Subaru chose to set the rev limiter below 7K on the "normal" 2.5s and below 8K on the 2.5 STis....
So would Dave's but if you look at the graph you'll understand why we don't. No point in revving the butt off an engine if you don't have to! Rev limiter is set to 7K, and we don't bounce cars off the limiter on the dyno.
Why not ? Extrapolating experience of 2 litre motors to 2.5s won't work, they behave differently and need to be tuned differently. Why sacrifice torque to get a little bit more power at the top when there's no more air available up there anyway ?
We wanted to build a quick road car, not a dyno queen. This car maintains 90% or more of peak power from 4300RPM to 6800RPM. This permits the car to be driven permanently in the 90% window. If you change at 6500RPM and say you have a 0.72 ratio between cogs, you will end up at 4680RPM after the shift, at around 428BHP....
That's based on a number of assumptions which may or may not be true. The cam timing chosen is suitable for midrange torque, so the VE falls off rapidly at the top end. The only way to get the air into the engine to push the power peak up in the rev range is to force it in by raising the boost. What if the turbine mass flow rate has already been achieved ? The only way to deliver the extra power to the compressor to raise the boost is to raise the EGBP, but in doing so you make the VE even worse.
As it stands, we have achieved the power and torque without needing to rev the engine to dizzy RPMs. This is not a race car or a dyno queen, it's a road car. The power band is very flexible, if you're in a hurry you can hold it at over 90% power all the time. Again without revving the thing like mad. What's "wrong" with that ?
Cheers,
Pat.
OK, if you want to be pedantic, they WILL rev that high but it's not wise. You could ask yourself why Subaru chose to set the rev limiter below 7K on the "normal" 2.5s and below 8K on the 2.5 STis....
So would Dave's but if you look at the graph you'll understand why we don't. No point in revving the butt off an engine if you don't have to! Rev limiter is set to 7K, and we don't bounce cars off the limiter on the dyno.
Why not ? Extrapolating experience of 2 litre motors to 2.5s won't work, they behave differently and need to be tuned differently. Why sacrifice torque to get a little bit more power at the top when there's no more air available up there anyway ?
We wanted to build a quick road car, not a dyno queen. This car maintains 90% or more of peak power from 4300RPM to 6800RPM. This permits the car to be driven permanently in the 90% window. If you change at 6500RPM and say you have a 0.72 ratio between cogs, you will end up at 4680RPM after the shift, at around 428BHP....
That's based on a number of assumptions which may or may not be true. The cam timing chosen is suitable for midrange torque, so the VE falls off rapidly at the top end. The only way to get the air into the engine to push the power peak up in the rev range is to force it in by raising the boost. What if the turbine mass flow rate has already been achieved ? The only way to deliver the extra power to the compressor to raise the boost is to raise the EGBP, but in doing so you make the VE even worse.
As it stands, we have achieved the power and torque without needing to rev the engine to dizzy RPMs. This is not a race car or a dyno queen, it's a road car. The power band is very flexible, if you're in a hurry you can hold it at over 90% power all the time. Again without revving the thing like mad. What's "wrong" with that ?
Cheers,
Pat.
Well said that man, and nice job
The 'Max Powa' brigade drive me nuts with their obsession with peak power
600bhp at 8000rpm is about as much use as Chelsea's defence if you're only making 200bhp below 6krpm
Power is only any good if you can use it
Which I bet Dave will beI bet someone at Pirelli/Bridgestone/Michelin or whoever is reading this thread & rubbing their hands
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Joined: Jul 2000
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From: Glasgow
The cam timing chosen is suitable for midrange torque,
I was talking to the chap that maps my car just at the turn of the year about changing engine spec to get power/torque a lot lower down over what i had in 2005.
Are you able to share what cam timing that car runs to get that type of power band? (I'll understand if it's a commercial interest which stops you, just say so).
Does this one have aftermarket cams? I think it does?
Cheers
Thread Starter
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Joined: Mar 2003
Posts: 938
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From: Derby
It is acyually some one at goodyear
Thread Starter
Scooby Regular
Joined: Mar 2003
Posts: 938
Likes: 0
From: Derby
EJ257 open deck block
Wiseco forged pistons
PAR forged con rods
Race uprated bearings
STi 5 heads, polished & ported, gas flowed and standard STi 5 cams
Jun adjustable cam pulleys
Kevlar cam belt
Garrett GT30R turbo rotated 45 degrees
Turbosmart pro-gate 48mm external wastegate
Custom 2” screamer pipe
ARP head bolts
Custom Inlet manifold modified to equal length and turned round with custom throttle body
Lateral Performance Front-mount intercooler and radiator kit
Custom pipe work for front mount
Aquamist water injection system 1S with tank located in boot with extra pump
Walbro fuel pump
HGK iridium race plugs
FSE adjustable fuel regulator
Bespoke braided equal-length fuel rails
Nismo 740cc injectors
Oil cooler mounted in front of Intercooler
Gruppe S headers with ceramic coating
Custom up and down pipe with lagging on up-pipe
Fujitsubo 3in exhaust system from down-pipe back with 5in back box
GGR K&N Air filter with lateral performance alloy trumpet
Go faster bits lightweight blue engine pulleys
Go faster bits blue blow off valve
Modified breather system with Helix catch can
Air conditioning removed
Autronic ECu running 1.65 Bar
Turbo smart 3 port boost solenoid
Highbury sport custom silicon hose set
TRANSMISSION:
Exceedy twin plate clutch
Exceedy Flywheel
Modena 5 speed Dog Box with steel selector forks on gears 1-4, 3.9:1 final drive and a gear selection interlock, with a 1.1:1 drop gear and viscous centre diff
Quaife ATB Diff
Wiseco forged pistons
PAR forged con rods
Race uprated bearings
STi 5 heads, polished & ported, gas flowed and standard STi 5 cams
Jun adjustable cam pulleys
Kevlar cam belt
Garrett GT30R turbo rotated 45 degrees
Turbosmart pro-gate 48mm external wastegate
Custom 2” screamer pipe
ARP head bolts
Custom Inlet manifold modified to equal length and turned round with custom throttle body
Lateral Performance Front-mount intercooler and radiator kit
Custom pipe work for front mount
Aquamist water injection system 1S with tank located in boot with extra pump
Walbro fuel pump
HGK iridium race plugs
FSE adjustable fuel regulator
Bespoke braided equal-length fuel rails
Nismo 740cc injectors
Oil cooler mounted in front of Intercooler
Gruppe S headers with ceramic coating
Custom up and down pipe with lagging on up-pipe
Fujitsubo 3in exhaust system from down-pipe back with 5in back box
GGR K&N Air filter with lateral performance alloy trumpet
Go faster bits lightweight blue engine pulleys
Go faster bits blue blow off valve
Modified breather system with Helix catch can
Air conditioning removed
Autronic ECu running 1.65 Bar
Turbo smart 3 port boost solenoid
Highbury sport custom silicon hose set
TRANSMISSION:
Exceedy twin plate clutch
Exceedy Flywheel
Modena 5 speed Dog Box with steel selector forks on gears 1-4, 3.9:1 final drive and a gear selection interlock, with a 1.1:1 drop gear and viscous centre diff
Quaife ATB Diff
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From: Glasgow
Nope Standard STi 5 cams
Custom 2” screamer pipe
Do you not find that really noisy in road use? I couldn't stand mine when it was a screamer. Had to get it plumbed back into the main system.
Thread Starter
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Joined: Mar 2003
Posts: 938
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From: Derby
Nope. It only kicks in after around 1 bar(I think) so its not too bad. You cant hear it that much anyway due to the amount of noise the turbo makes
Scooby Regular
Joined: Sep 2001
Posts: 9,465
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From: The Cheshire end of the emasculated Cat & Fiddle
As soon as I posted it I knew you'd be on Goodyears or Dunlops
That's an impressive list of parts & work
MrsD would go apesh!t if I tried to get even a tenth of that done to my scoob and to be fair so would the car, seeing as it's a 98k/13 year old LegacyEnjoy it mate
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Joined: Sep 2004
Posts: 23,118
Likes: 150
From: Notts
Quote:
Originally Posted by harvey
Peak power at 5,300 rpm. ? This seems very unlikely ?
Any explanation ?
rafpmsl
Originally Posted by harvey
Peak power at 5,300 rpm. ? This seems very unlikely ?
Any explanation ?
rafpmsl