KW to BHP Conversion?
02 June 2001, 03:55 PM
#3
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Cheers Wrexy! 
The figures are the ones quoted by Hyperflow for their new FMIC fitted on a standard Scoob. I'll soon be fitting one to CK1, so was curious what gains to expect.
A 24bhp increase at the wheels seems phenominal though! That would equate to a flywheel figure of what, about 30bhp?
I hope so!!!
Stef.
[This message has been edited by Stef (edited 02 June 2001).]
The figures are the ones quoted by Hyperflow for their new FMIC fitted on a standard Scoob. I'll soon be fitting one to CK1, so was curious what gains to expect.
A 24bhp increase at the wheels seems phenominal though! That would equate to a flywheel figure of what, about 30bhp?
I hope so!!!
Stef.
[This message has been edited by Stef (edited 02 June 2001).]
02 June 2001, 04:18 PM
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Stef it should be closer to 34bhp at the flywheel given that Scoobs lose around 40% of power to the wheels. I've seen power increases like that on 4wd RR's back in OZ
on Scoobs that fitted the FMIC. It's a very common mod in OZ.
Cheers,
WREXY.
[This message has been edited by WREXY (edited 02 June 2001).]
[This message has been edited by WREXY (edited 02 June 2001).]
on Scoobs that fitted the FMIC. It's a very common mod in OZ.
Cheers,
WREXY.
[This message has been edited by WREXY (edited 02 June 2001).]
[This message has been edited by WREXY (edited 02 June 2001).]
02 June 2001, 04:48 PM
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Oh dear, where to start ? 
Wrexy: drivetrain losses are fixed, not a percentage. Think about it: why would you loose more when your engine power goes up. Doesn't compute. Or vice versa: when my aircon kicks in, I have less drivetrain losses ?
Stef: a FMIC would not even give one bhp more in winter, as you are already pretty close to optimal charge cooling. It may make a difference in summer, BUT :
. big chance it will increase lag, *especially* if you keep your dump valve, because if the large pipe work (unless you turn around your intake manifold and a few other bits ... )
. it will cover part of your radiator, so less optimal water cooling, so less optimal oil cooling etc etc...
Try a bigger / more efficient turbo first (VF23, or hybrid etc..), and then see/measure how much you loose in warmer weather.
Tuning is not a question of: I add bit A) it gives me 15 bhp. Add bit B) and another 34 BHP.
I'm sure you need a FMIC when going for the "big" BHP numbers, but you can get safely to say 280-300 bhp without needing such a BIG change to your car (it's not exactly a straightforward bolt on mod)
I haveth spoken
Theo
Wrexy: drivetrain losses are fixed, not a percentage. Think about it: why would you loose more when your engine power goes up. Doesn't compute. Or vice versa: when my aircon kicks in, I have less drivetrain losses ?
Stef: a FMIC would not even give one bhp more in winter, as you are already pretty close to optimal charge cooling. It may make a difference in summer, BUT :
. big chance it will increase lag, *especially* if you keep your dump valve, because if the large pipe work (unless you turn around your intake manifold and a few other bits ... )
. it will cover part of your radiator, so less optimal water cooling, so less optimal oil cooling etc etc...
Try a bigger / more efficient turbo first (VF23, or hybrid etc..), and then see/measure how much you loose in warmer weather.
Tuning is not a question of: I add bit A) it gives me 15 bhp. Add bit B) and another 34 BHP.
I'm sure you need a FMIC when going for the "big" BHP numbers, but you can get safely to say 280-300 bhp without needing such a BIG change to your car (it's not exactly a straightforward bolt on mod)
I haveth spoken
Theo
02 June 2001, 06:19 PM
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Hi Theo,
You're right it would be a fixed amount of power loss to the wheels, but on a stock UK spec Scoob it equates to around 40% loss to the wheels from the RR's I have gone off. I guess I mixed it up thinking all Scoobs lost 40% regardless of different hp.
I have seen big power gains from cars that fitted FMIC in OZ, in obviously warmer weather than the UK, but they also were tuned for the mods too, such as a Unichip and some with bigger turbo's . What you are saying does make sense though as it is cooler in the UK.
Cheers,
WREXY.
You're right it would be a fixed amount of power loss to the wheels, but on a stock UK spec Scoob it equates to around 40% loss to the wheels from the RR's I have gone off. I guess I mixed it up thinking all Scoobs lost 40% regardless of different hp.
I have seen big power gains from cars that fitted FMIC in OZ, in obviously warmer weather than the UK, but they also were tuned for the mods too, such as a Unichip and some with bigger turbo's . What you are saying does make sense though as it is cooler in the UK.
Cheers,
WREXY.
03 June 2001, 03:56 AM
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sorry guys
i have to disagree with you to a certain extent. the FMIC will make more power regardless if it is winter or summer. it will obviously make more difference in the summer though. all it takes is couple of laps on a track on full boost to raise the inlet temps. so even it was winter don't under estimate how hot things can get in a turbo engine.
YOU CAN NEVER HAVE ENOUGH COOLING IN A TURBO ENGINE.
sam
soon to have an APS SPEC R FMIC when it arrives. and then i will break the 300bhp barrier.
i have to disagree with you to a certain extent. the FMIC will make more power regardless if it is winter or summer. it will obviously make more difference in the summer though. all it takes is couple of laps on a track on full boost to raise the inlet temps. so even it was winter don't under estimate how hot things can get in a turbo engine.
YOU CAN NEVER HAVE ENOUGH COOLING IN A TURBO ENGINE.
sam
soon to have an APS SPEC R FMIC when it arrives. and then i will break the 300bhp barrier.
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04 June 2001, 12:52 AM
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Adam.
My car will be the first in the UK to have the Hyperflow fmic fitted. I like trying new things.
It is currently the largest fmic available for the Scoob, which probably doesn't mean a great deal but if you look at their site here
My car will be the first in the UK to have the Hyperflow fmic fitted. I like trying new things.
It is currently the largest fmic available for the Scoob, which probably doesn't mean a great deal but if you look at their site here
04 June 2001, 11:31 AM
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One other thing wrexy, 40% loss of power means the intercooler would give 40bhp at the flywheel not 34, so with these percentage in mind, it sounds even more impressive.
I think sam is right though, plus rolling road figures would also show a more substantial gain, as heat soak is significantly reduced using a front mount, as well as being more efficiently cooled by the fans.
there is also the looks question to consider. stef, do it. I'm gonna.
but before you consider hyperflow as the only one, look around, there are other makes which dont route the pipework in the same way and therefore make it considerably shorter negating the point theo made relating to lag and reversing the manifold.
With this set up, reversing the manifold is unnecessary, as the difference in pipework length is almost insignificant.
There are loads of other issues to consider though. I thought front mounted intercoolers were just better but it isnt true, there are loads of choices that have to be made in their design. it is a very complicated business. I would say ask pat to explain but most people would tend to get lost. Needless to say, before buying any fmic, ask to see RR graphs to get you in the general area of the difference made, and try to drive a demonstrator vehicle which is as standard as possible apart from the mod, at least that way you might be able to guage what will happen.
A mod like this could seriously affect the drivability of your car.
That said, even if lag is introduced, on a track car such as yours, it wont be an issue.
I think sam is right though, plus rolling road figures would also show a more substantial gain, as heat soak is significantly reduced using a front mount, as well as being more efficiently cooled by the fans.
there is also the looks question to consider. stef, do it. I'm gonna.
but before you consider hyperflow as the only one, look around, there are other makes which dont route the pipework in the same way and therefore make it considerably shorter negating the point theo made relating to lag and reversing the manifold.
With this set up, reversing the manifold is unnecessary, as the difference in pipework length is almost insignificant.
There are loads of other issues to consider though. I thought front mounted intercoolers were just better but it isnt true, there are loads of choices that have to be made in their design. it is a very complicated business. I would say ask pat to explain but most people would tend to get lost. Needless to say, before buying any fmic, ask to see RR graphs to get you in the general area of the difference made, and try to drive a demonstrator vehicle which is as standard as possible apart from the mod, at least that way you might be able to guage what will happen.
A mod like this could seriously affect the drivability of your car.
That said, even if lag is introduced, on a track car such as yours, it wont be an issue.
04 June 2001, 01:25 PM
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Stef,
You should keep an eye on your oil, and to a lesser extent, water temperatures when you fit the fmic... an additional oil cooler system may be a very good idea with regards to engine longevity. Fitting a fmic WILL reduce your cooling systems efficiency and is likely to raise your oil temps significantly, especially on track/ring.
Oh, and have you thought about the best way to mount the FMIC such that you don't have to replace/recore the unit absolutely everytime you _potentially_ have a coming together of CK1's front and a tyre wall.
Moray
You should keep an eye on your oil, and to a lesser extent, water temperatures when you fit the fmic... an additional oil cooler system may be a very good idea with regards to engine longevity. Fitting a fmic WILL reduce your cooling systems efficiency and is likely to raise your oil temps significantly, especially on track/ring.
Oh, and have you thought about the best way to mount the FMIC such that you don't have to replace/recore the unit absolutely everytime you _potentially_
have a coming together of CK1's front and a tyre wall.Moray
04 June 2001, 02:06 PM
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Stef,
Should look awesome, and i think black is a better colour since it radiates anyway.
Will look at graphs, but will be interested to see what you think.
lag, has been reported to be pretty okay, and apparently if it does cause a prob can be mapped out if yiou have the facility.
The hyperflow certainly does look great. I hope you like it!
Should look awesome, and i think black is a better colour since it radiates anyway.
Will look at graphs, but will be interested to see what you think.
lag, has been reported to be pretty okay, and apparently if it does cause a prob can be mapped out if yiou have the facility.
The hyperflow certainly does look great. I hope you like it!
04 June 2001, 05:30 PM
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Adam,
Doesn't a black surface _absorb_ more energy than a lighter coloured surface would? Isn't it a reflection thing? Hence Solar Panels are made in black so they _collect_ more sunlight/heat?
My m3's black interior and exterior certainly seem to absorb a lot more heat than my lighter coloured scooby did.
Moray
Doesn't a black surface _absorb_ more energy than a lighter coloured surface would? Isn't it a reflection thing? Hence Solar Panels are made in black so they _collect_ more sunlight/heat?
My m3's black interior and exterior certainly seem to absorb a lot more heat than my lighter coloured scooby did.
Moray
04 June 2001, 05:52 PM
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yes moray, you are indeed correct. to some extent.
Black does absorb better than white or shiny reflective surfaces, but it also radiates heat faster. given that the front mount is kind of behind recessed in the aperture of the mouth of the car, it is not likely to absorb much radiation, therefore it being black isnt such a big deal, yet it will still radiate quickly, therefore it is better that way.
If you want to understand this, do a search for stefans radiation constant, and also try the word albedo, which relates to the effect of the shininess.
to some extent.Black does absorb better than white or shiny reflective surfaces, but it also radiates heat faster. given that the front mount is kind of behind recessed in the aperture of the mouth of the car, it is not likely to absorb much radiation, therefore it being black isnt such a big deal, yet it will still radiate quickly, therefore it is better that way.
If you want to understand this, do a search for stefans radiation constant, and also try the word albedo, which relates to the effect of the shininess.
04 June 2001, 10:55 PM
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>>also try the word albedo, which relates to the effect of the shininess.
You want sad ? You want sad ? ... Vangelis had a song that was called Albedo 0.35 (from memory, could have been another number )
Was related to the reclection of the moon.
Theo
You want sad ? You want sad ? ... Vangelis had a song that was called Albedo 0.35 (from memory, could have been another number
)Was related to the reclection of the moon.
Theo
04 June 2001, 11:47 PM
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With respect to Moray's comments and that I am no expert, however do keep in contact with my good m8 in OZ who owns and is a performance specialist with a 4wd RR and is a distributor of APS, Unichip and has fitted, APS FMIC's to numerous cars , I would like to add that lots of cars in OZ are running front mount intercoolers without additional oil coolers on road and track with no or little temperature increases.
Stef, let us know how you go with the fitting, that is, is it a straight bolt on kit, with only the bumper needing cutting and also how strong the power feels compared to before.
Cheers,
WREXY.
Stef, let us know how you go with the fitting, that is, is it a straight bolt on kit, with only the bumper needing cutting and also how strong the power feels compared to before.
Cheers,
WREXY.
05 June 2001, 12:09 AM
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Theo
sorry mate....guess my comment was a bit snappy
...too much work, not enough sleep ;-)
I agree with you - it's never as simple as 'this bit plus that bit gives you X bhp'
Nick
sorry mate....guess my comment was a bit snappy
...too much work, not enough sleep ;-)
I agree with you - it's never as simple as 'this bit plus that bit gives you X bhp'
Nick
05 June 2001, 12:11 AM
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If you look at my 3rd post you will read that the 40% power loss I've calculated is from a RR I've gone off as different RR's give different power readings at the wheels but Subaru always claim 215bhp at the flywheel. So the drive train power losses will be different from one RR to another RR.
Cheers
Cheers
05 June 2001, 12:30 AM
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WREXY,
I believe Nito is running a front mount intercooler over in this hemisphere and has observed increases in oil temperature... Stef drives his car hard... I think it may be worth him keeping an eye on the oil temperatures and taking preventative action if they are significantly increased.
If you put any restriction in front of the standard cooling system, it will reduce it's efficiency... if you put a massive intercooler core right across the radiator's airfeed you will reduce the cooling available... remember the intercooler does, at times, work as an air to air radiator, so it will not only restrict airflow to the rad, it will also preheat the restricted air.
Moray
I believe Nito is running a front mount intercooler over in this hemisphere and has observed increases in oil temperature... Stef drives his car hard... I think it may be worth him keeping an eye on the oil temperatures and taking preventative action if they are significantly increased.
If you put any restriction in front of the standard cooling system, it will reduce it's efficiency... if you put a massive intercooler core right across the radiator's airfeed you will reduce the cooling available... remember the intercooler does, at times, work as an air to air radiator, so it will not only restrict airflow to the rad, it will also preheat the restricted air.
Moray
05 June 2001, 12:31 AM
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No probs Nick
Wrexy, re dual entry ... that's exactly why I'm feeling a tad frustrated over this tuning stuff: how much of it is marketing ... ? I think if you would gather all the marketing BS into one big pile, you could easily reach the moon
But to be honest: maybe next year I'll be very vocal in defending the advantages of FMIC's on this same bbs
Wrexy, re dual entry ... that's exactly why I'm feeling a tad frustrated over this tuning stuff: how much of it is marketing ... ? I think if you would gather all the marketing BS into one big pile, you could easily reach the moon
But to be honest: maybe next year I'll be very vocal in defending the advantages of FMIC's on this same bbs
05 June 2001, 12:44 AM
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Probably stick with the idea of a TMIC, but how does the MRT TMIC cooler compare with say an APS one?
I have options on both, but a secondhand MRT one will probably cost the same as a new APS one!
Andy
I have options on both, but a secondhand MRT one will probably cost the same as a new APS one!
Andy
05 June 2001, 10:31 AM
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agree with theo.
but would expect the aps to work well.
There is a massive amount that goes into intercooler design. Read Maximum boost to find out exactly how much.
I did. Big mistake.
It is a trade off between heatloss and flow.
If you have a big intercooler, it has a lot of volume, which means it will generate more lag.
if it is internally restrictive, it requires more pressure to drive the air through, and therefore the turbo has to work harder, which generates more heat.
if it is less restictive, the pressure required is less, but a clean path through, means the air has less opportunity to give up its heat to the core.
If it is a dense core, which is efficient at giving heat to the fins etc, than incident air flow cannot get through it.
If it isnt a dense core, air can blow past teh fins very easily, but it doesnt do a great job of cooling the internal air.
Its all a trade off, so dont assume, biggest is best. It isnt that simple.
All I can say is biggest is prettiest.
there are intercoolers out there that require no bumper cutting, there are also some which require cutting the brace underneath the bonnet catch, and supporting the front cross member in a different way.
A top mount is certainly easier and cheaper, and water spray and injection will improve things, but I would guess heat soak is the main problem, which will affect an fmic much less.
but would expect the aps to work well.
There is a massive amount that goes into intercooler design. Read Maximum boost to find out exactly how much.
I did. Big mistake.
It is a trade off between heatloss and flow.
If you have a big intercooler, it has a lot of volume, which means it will generate more lag.
if it is internally restrictive, it requires more pressure to drive the air through, and therefore the turbo has to work harder, which generates more heat.
if it is less restictive, the pressure required is less, but a clean path through, means the air has less opportunity to give up its heat to the core.
If it is a dense core, which is efficient at giving heat to the fins etc, than incident air flow cannot get through it.
If it isnt a dense core, air can blow past teh fins very easily, but it doesnt do a great job of cooling the internal air.
Its all a trade off, so dont assume, biggest is best. It isnt that simple.
All I can say is biggest is prettiest.
there are intercoolers out there that require no bumper cutting, there are also some which require cutting the brace underneath the bonnet catch, and supporting the front cross member in a different way.
A top mount is certainly easier and cheaper, and water spray and injection will improve things, but I would guess heat soak is the main problem, which will affect an fmic much less.