FAO tuners & engine builders or anyone in the know.
25-09-2012, 06:01 PM
#1
300+
Thread Starter
iTrader: (2)
Join Date: May 2004
Location: either at work or on way :)
Posts: 27,262
Received 585 Likes
on
517 Posts
FAO tuners & engine builders or anyone in the know.
Basically I want your views and opinions on how and what's needed to run a low lagg turbo to 44psi or more... And what engine and components to use or need so the air consumed is used.... As I'm wanting to build/ have built a engine to this spec.... Any help or advise please.
25-09-2012, 06:31 PM
#3
A rather random way to spec an engine....I want to run 44psi ?
Now that is just weird. Is there any reasoning behind it ?
Engine internals or spec is less of an issue than fuel used, intercooling, turbocharger and of course ecu tuning etc etc
Head gasket sealing will need well taken care of as well. And the usage of the engine will matter. Is it for short blasts, or do you want to run at full throttle all day ?
But crank, rods, pistons etc hardly matter as long as they are good quality.
Now that is just weird. Is there any reasoning behind it ?
Engine internals or spec is less of an issue than fuel used, intercooling, turbocharger and of course ecu tuning etc etc
Head gasket sealing will need well taken care of as well. And the usage of the engine will matter. Is it for short blasts, or do you want to run at full throttle all day ?
But crank, rods, pistons etc hardly matter as long as they are good quality.
25-09-2012, 06:38 PM
#5
300+
Thread Starter
iTrader: (2)
Join Date: May 2004
Location: either at work or on way :)
Posts: 27,262
Received 585 Likes
on
517 Posts
A rather random way to spec an engine....I want to run 44psi ?
Now that is just weird. Is there any reasoning behind it ?
Engine internals or spec is less of an issue than fuel used, intercooling, turbocharger and of course ecu tuning etc etc
Head gasket sealing will need well taken care of as well. And the usage of the engine will matter. Is it for short blasts, or do you want to run at full throttle all day ?
But crank, rods, pistons etc hardly matter as long as they are good quality.
Now that is just weird. Is there any reasoning behind it ?
Engine internals or spec is less of an issue than fuel used, intercooling, turbocharger and of course ecu tuning etc etc
Head gasket sealing will need well taken care of as well. And the usage of the engine will matter. Is it for short blasts, or do you want to run at full throttle all day ?
But crank, rods, pistons etc hardly matter as long as they are good quality.
Car will only be occasionally run as its for my 3dr.
For the odd blast... I just want to build or have built a very high boost low lag engine.
Last edited by Rsmat; 25-09-2012 at 06:39 PM.
25-09-2012, 06:40 PM
#6
Didnt sound like it ?
Why not state what you intend to use the car for, what sort of power/torque you want to achieve, what sort of budget you have. Is it purely for racing, or road use ? Will you be using race fuel, or pump fuel ?
Asking to spec an engine for 44psi boost is just weird.
Why not state what you intend to use the car for, what sort of power/torque you want to achieve, what sort of budget you have. Is it purely for racing, or road use ? Will you be using race fuel, or pump fuel ?
Asking to spec an engine for 44psi boost is just weird.
25-09-2012, 06:48 PM
#7
Happily retired
44psi is 3bar.
Ran 2.9bar on my MAD 500bhp engine using a t4 back in 1743. Think mine runs 2.8bar on a GTX4202 so either of those could be tadded up to 3 bar im sure
think i also ran 2.9 bar on a GT4094 & A GT4210 so lots of choice there now if only you would drop the criteria of low lag 
. As a matter of interest we ran 4bar down Brunters & it made a bloody mess of the head gasket when the waste gate pipe came off.
Ran 2.9bar on my MAD 500bhp engine using a t4 back in 1743. Think mine runs 2.8bar on a GTX4202 so either of those could be tadded up to 3 bar im sure
think i also ran 2.9 bar on a GT4094 & A GT4210 so lots of choice there now if only you would drop the criteria of low lag . As a matter of interest we ran 4bar down Brunters & it made a bloody mess of the head gasket when the waste gate pipe came off.
Trending Topics
25-09-2012, 06:57 PM
#8
300+
Thread Starter
iTrader: (2)
Join Date: May 2004
Location: either at work or on way :)
Posts: 27,262
Received 585 Likes
on
517 Posts
Didnt sound like it ?
Why not state what you intend to use the car for, what sort of power/torque you want to achieve, what sort of budget you have. Is it purely for racing, or road use ? Will you be using race fuel, or pump fuel ?
Asking to spec an engine for 44psi boost is just weird.
Why not state what you intend to use the car for, what sort of power/torque you want to achieve, what sort of budget you have. Is it purely for racing, or road use ? Will you be using race fuel, or pump fuel ?
Asking to spec an engine for 44psi boost is just weird.
Oh right I thought the bit that said what's needed covered that...
It will be pump fuel and for my pleasure only on the road.
Why is it wierd... Everyone wants something including yourself so are you wierd aswell ?... Sorry it's probably me as I am confusing lol...
ROD I don't want lagg full stop mate... If you could have your turbo coming in a little lower you probably would right..?
Rod do you mind telling me your full spec that you had at 500 please mate.
25-09-2012, 07:09 PM
#9
Oh right I thought the bit that said what's needed covered that...
It will be pump fuel and for my pleasure only on the road.
Why is it wierd... Everyone wants something including yourself so are you wierd aswell ?... Sorry it's probably me as I am confusing lol...
ROD I don't want lagg full stop mate... If you could have your turbo coming in a little lower you probably would right..?
Rod do you mind telling me your full spec that you had at 500 please mate.
It will be pump fuel and for my pleasure only on the road.
Why is it wierd... Everyone wants something including yourself so are you wierd aswell ?... Sorry it's probably me as I am confusing lol...
ROD I don't want lagg full stop mate... If you could have your turbo coming in a little lower you probably would right..?
Rod do you mind telling me your full spec that you had at 500 please mate.
25-09-2012, 07:17 PM
#10
300+
Thread Starter
iTrader: (2)
Join Date: May 2004
Location: either at work or on way :)
Posts: 27,262
Received 585 Likes
on
517 Posts
I'm not going to chase power all im wanting is 44psi or more a turbo that will at least half last out and a engine that will take and consume the air... I couldnt care if I only got 300bhp and 400ftlb... It's not about that for me it's about boost.
Last edited by Rsmat; 25-09-2012 at 07:18 PM.
25-09-2012, 07:23 PM
#11
Borg Warner EFR Equipped!
Join Date: Apr 2005
Location: In the unit, building a 450bhp Time Attack Focus!
Posts: 5,810
Likes: 0
Received 2 Likes
on
2 Posts
Matt,
Boost pressure is a measure of restriction in the engine, for example, if you ported the cylinder head on an engine that was running 34psi and changed nothing else, then I would expect that engine to be running maybe 28psi afterwards as it would flow better.
Turbochargers have an efficiency range where the air they are compressing comes out efficiently, i.e a large quantity of air at a given temperature. When the turbocharger exceeds this efficiency range, the air coming out is significantly hotter and cannot be regulated as well by your intercooler. You tend to find that bigger turbos need to run higher boost pressures to enter this efficiency window, i.e a T3 turbo is efficient between 14psi and 20psi, yet a GT42R is efficient between 38psi and 48psi (for example).
Saying that you want a small turbo to run massive boost pressures will probably not actually result in a faster car. Running a T34 at 44psi will generate very high air charge temperatures, the resulting reduction in oxygen content will limit the power production and on the dyno, it will most likely not give you a gain in power.
Your peak cylinder pressures will however increase significantly, especially around peak torque, this is more likely to highlight weaknesses in head gasket integrity.
In summary mate, the key to making your car faster is to increase the engine efficiency rather than just the boost pressure
Boost pressure is a measure of restriction in the engine, for example, if you ported the cylinder head on an engine that was running 34psi and changed nothing else, then I would expect that engine to be running maybe 28psi afterwards as it would flow better.
Turbochargers have an efficiency range where the air they are compressing comes out efficiently, i.e a large quantity of air at a given temperature. When the turbocharger exceeds this efficiency range, the air coming out is significantly hotter and cannot be regulated as well by your intercooler. You tend to find that bigger turbos need to run higher boost pressures to enter this efficiency window, i.e a T3 turbo is efficient between 14psi and 20psi, yet a GT42R is efficient between 38psi and 48psi (for example).
Saying that you want a small turbo to run massive boost pressures will probably not actually result in a faster car. Running a T34 at 44psi will generate very high air charge temperatures, the resulting reduction in oxygen content will limit the power production and on the dyno, it will most likely not give you a gain in power.
Your peak cylinder pressures will however increase significantly, especially around peak torque, this is more likely to highlight weaknesses in head gasket integrity.
In summary mate, the key to making your car faster is to increase the engine efficiency rather than just the boost pressure
25-09-2012, 07:27 PM
#12
What do you want a specific boost level? That is weird.
What is it you actually want? Power, torque, a massive kick in the back when it comes on boost?.
What's this about an engine that can consume the air? What air? You realise that there is a massive difference in air flow between a t3 at 44 psi and a GT40 at 44psi?
What is it you actually want? Power, torque, a massive kick in the back when it comes on boost?.
What's this about an engine that can consume the air? What air? You realise that there is a massive difference in air flow between a t3 at 44 psi and a GT40 at 44psi?
25-09-2012, 07:37 PM
#13
What do you want a specific boost level? That is weird.
What is it you actually want? Power, torque, a massive kick in the back when it comes on boost?.
What's this about an engine that can consume the air? What air? You realise that there is a massive difference in air flow between a t3 at 44 psi and a GT40 at 44psi?
What is it you actually want? Power, torque, a massive kick in the back when it comes on boost?.
What's this about an engine that can consume the air? What air? You realise that there is a massive difference in air flow between a t3 at 44 psi and a GT40 at 44psi?
compound charging is what you require
or a viper 8.3 litre v10 twin turbo you might want to forget the 44 psi of boost though
Last edited by Turbosystems; 25-09-2012 at 07:41 PM.
25-09-2012, 07:40 PM
#14
300+
Thread Starter
iTrader: (2)
Join Date: May 2004
Location: either at work or on way :)
Posts: 27,262
Received 585 Likes
on
517 Posts
Matt,
Boost pressure is a measure of restriction in the engine, for example, if you ported the cylinder head on an engine that was running 34psi and changed nothing else, then I would expect that engine to be running maybe 28psi afterwards as it would flow better.
Turbochargers have an efficiency range where the air they are compressing comes out efficiently, i.e a large quantity of air at a given temperature. When the turbocharger exceeds this efficiency range, the air coming out is significantly hotter and cannot be regulated as well by your intercooler. You tend to find that bigger turbos need to run higher boost pressures to enter this efficiency window, i.e a T3 turbo is efficient between 14psi and 20psi, yet a GT42R is efficient between 38psi and 48psi (for example).
Saying that you want a small turbo to run massive boost pressures will probably not actually result in a faster car. Running a T34 at 44psi will generate very high air charge temperatures, the resulting reduction in oxygen content will limit the power production and on the dyno, it will most likely not give you a gain in power.
Your peak cylinder pressures will however increase significantly, especially around peak torque, this is more likely to highlight weaknesses in head gasket integrity.
In summary mate, the key to making your car faster is to increase the engine efficiency rather than just the boost pressure
Boost pressure is a measure of restriction in the engine, for example, if you ported the cylinder head on an engine that was running 34psi and changed nothing else, then I would expect that engine to be running maybe 28psi afterwards as it would flow better.
Turbochargers have an efficiency range where the air they are compressing comes out efficiently, i.e a large quantity of air at a given temperature. When the turbocharger exceeds this efficiency range, the air coming out is significantly hotter and cannot be regulated as well by your intercooler. You tend to find that bigger turbos need to run higher boost pressures to enter this efficiency window, i.e a T3 turbo is efficient between 14psi and 20psi, yet a GT42R is efficient between 38psi and 48psi (for example).
Saying that you want a small turbo to run massive boost pressures will probably not actually result in a faster car. Running a T34 at 44psi will generate very high air charge temperatures, the resulting reduction in oxygen content will limit the power production and on the dyno, it will most likely not give you a gain in power.
Your peak cylinder pressures will however increase significantly, especially around peak torque, this is more likely to highlight weaknesses in head gasket integrity.
In summary mate, the key to making your car faster is to increase the engine efficiency rather than just the boost pressure
Cheers will that's cleared a lot up for me....
What do you want a specific boost level? That is weird.
What is it you actually want? Power, torque, a massive kick in the back when it comes on boost?.
What's this about an engine that can consume the air? What air? You realise that there is a massive difference in air flow between a t3 at 44 psi and a GT40 at 44psi?
What is it you actually want? Power, torque, a massive kick in the back when it comes on boost?.
What's this about an engine that can consume the air? What air? You realise that there is a massive difference in air flow between a t3 at 44 psi and a GT40 at 44psi?
I wanted 44psi just wanted more boost for a lot more kick....
The reason I put consume is because mine surged at 38psi but didn't at 36.. So at 38 wasn't the engine not consuming the air ? Choking etc..?
25-09-2012, 07:47 PM
#18
Borg Warner EFR Equipped!
Join Date: Apr 2005
Location: In the unit, building a 450bhp Time Attack Focus!
Posts: 5,810
Likes: 0
Received 2 Likes
on
2 Posts
Matt, if it was surging, then that is the turbo producing more air than the engine can consume. The boost pressure backs up and opposes the rotation of the compressor wheel, as a result you get a torsional loading on the shaft which can cause failure.
The reason you can achieve a big 'spike' as a peak boost and then see a reduction through the engine speed range is the efficiency change. At 4000rpm the engine is less efficient than at 6000rpm, the increase in efficiency at higher engine speeds means the boost is consumed by the engine which reduces the boost pressure seen in the plenum.
The reason you can achieve a big 'spike' as a peak boost and then see a reduction through the engine speed range is the efficiency change. At 4000rpm the engine is less efficient than at 6000rpm, the increase in efficiency at higher engine speeds means the boost is consumed by the engine which reduces the boost pressure seen in the plenum.
25-09-2012, 07:52 PM
#19
Professional Waffler
I hate the term the turbo is producing air that the engine can't consume. Surely that would just raise inlet pressure? (if under the stall line I add)
It's the turbine not producing enough torque
It's the turbine not producing enough torque
25-09-2012, 07:55 PM
#20
300+
Thread Starter
iTrader: (2)
Join Date: May 2004
Location: either at work or on way :)
Posts: 27,262
Received 585 Likes
on
517 Posts
You know me Gareth I'm wierd as Fook....
I read it mate...and I'm still thick...
I see so is it impossible to get a good 44psi boost spike our of a new turbo engine setup ?
Matt, if it was surging, then that is the turbo producing more air than the engine can consume. The boost pressure backs up and opposes the rotation of the compressor wheel, as a result you get a torsional loading on the shaft which can cause failure.
The reason you can achieve a big 'spike' as a peak boost and then see a reduction through the engine speed range is the efficiency change. At 4000rpm the engine is less efficient than at 6000rpm, the increase in efficiency at higher engine speeds means the boost is consumed by the engine which reduces the boost pressure seen in the plenum.
The reason you can achieve a big 'spike' as a peak boost and then see a reduction through the engine speed range is the efficiency change. At 4000rpm the engine is less efficient than at 6000rpm, the increase in efficiency at higher engine speeds means the boost is consumed by the engine which reduces the boost pressure seen in the plenum.
25-09-2012, 07:58 PM
#21
Borg Warner EFR Equipped!
Join Date: Apr 2005
Location: In the unit, building a 450bhp Time Attack Focus!
Posts: 5,810
Likes: 0
Received 2 Likes
on
2 Posts
If the engine efficiency was high enough to consume the given boost, then that resistance wouldn't be encountered, so surge can be reduced by reducing the target boost pressure at that given engine speed condition or by increasing the intake swallowing.
25-09-2012, 08:01 PM
#22
Borg Warner EFR Equipped!
Join Date: Apr 2005
Location: In the unit, building a 450bhp Time Attack Focus!
Posts: 5,810
Likes: 0
Received 2 Likes
on
2 Posts
You can get a 'kick in the back' without running huge spikes. Huge spikes have a nasty habit of finding the next weakest component in your engine or transmission!
25-09-2012, 08:12 PM
#23
Professional Waffler
Yes, but if the compressor wheel rotation wasn't being opposed by excessive pressure, the turbine wouldn't need greater torque to rotate it...
If the engine efficiency was high enough to consume the given boost, then that resistance wouldn't be encountered, so surge can be reduced by reducing the target boost pressure at that given engine speed condition or by increasing the intake swallowing.
If the engine efficiency was high enough to consume the given boost, then that resistance wouldn't be encountered, so surge can be reduced by reducing the target boost pressure at that given engine speed condition or by increasing the intake swallowing.
You could say if the turbine was slightly bigger it would produce enough torque and all will be fine. As you know there's a larger picture going on than most people think.
25-09-2012, 08:15 PM
#24
Borg Warner EFR Equipped!
Join Date: Apr 2005
Location: In the unit, building a 450bhp Time Attack Focus!
Posts: 5,810
Likes: 0
Received 2 Likes
on
2 Posts
I think people now are starting to accept that a 0.82 AR exhaust housing is actually superior to a 0.63 AR on a GT3076 for example, its a shame that its taken this long for the internet to accept this fact!
25-09-2012, 08:17 PM
#25
300+
Thread Starter
iTrader: (2)
Join Date: May 2004
Location: either at work or on way :)
Posts: 27,262
Received 585 Likes
on
517 Posts
It all depends what your target power figure is, what turbocharger you need to use to achieve that and whether there is anything beneficial to running such a boost spike...
You can get a 'kick in the back' without running huge spikes. Huge spikes have a nasty habit of finding the next weakest component in your engine or transmission!
You can get a 'kick in the back' without running huge spikes. Huge spikes have a nasty habit of finding the next weakest component in your engine or transmission!
Well I've drawn myself to a blank because I'm not chasing power... I just wanted something different like lots of boost lol....maybe I should stick with what I have as it has a big kick at 36psi on a T34.48
25-09-2012, 08:28 PM
#26
PassionFORD Member
iTrader: (1)
Join Date: May 2007
Posts: 5,768
Likes: 0
Received 0 Likes
on
0 Posts
Just to try clear a bit of confusion, I think in your head you were going along the lines of running a relatively average sized turbo with plenty of low end punch and then winding it up to 40psi+ to achieve good power yet have little lag although it appears things don't work that way, or at least that's how I interpreted what you were asking.
25-09-2012, 08:38 PM
#27
300+
Thread Starter
iTrader: (2)
Join Date: May 2004
Location: either at work or on way :)
Posts: 27,262
Received 585 Likes
on
517 Posts
Just to try clear a bit of confusion, I think in your head you were going along the lines of running a relatively average sized turbo with plenty of low end punch and then winding it up to 40psi+ to achieve good power yet have little lag although it appears things don't work that way, or at least that's how I interpreted what you were asking.
Bang on mate... Cheers
25-09-2012, 09:38 PM
#29
Other than that though, this thread HAS to be a wind up ?
25-09-2012, 09:45 PM
#30
300+
Thread Starter
iTrader: (2)
Join Date: May 2004
Location: either at work or on way :)
Posts: 27,262
Received 585 Likes
on
517 Posts
Why does it have to be a wind up... I'm dead seriouse... I was under the illusion that if I can run 36psi on literally a standard engine... Sure with a new uprated engine and different turbo I could run 44psi..!
So stop with all your technical shit I can't understand and keep it in thick mans terms so I can understand please...
25-09-2012, 09:56 PM
#32
Why does it have to be a wind up... I'm dead seriouse... I was under the illusion that if I can run 36psi on literally a standard engine... Sure with a new uprated engine and different turbo I could run 44psi..!
So stop with all your technical shit I can't understand and keep it in thick mans terms so I can understand please...
So stop with all your technical shit I can't understand and keep it in thick mans terms so I can understand please...
OK. If you build an engine that is capable of running 44psi of boost reliably on standard pump fuel, it will be terrible low down, and I still doubt you'd ever trust it to be reliable.
Or a better way. You could build a 1000cc engine that runs 44psi and makes 400bhp.
Or you could build a 4000cc engine that makes 400bhp at 1psi. ( although obviously you'd never build a turbo setup to use 1psi )
Now which would be better ? Clearly the larger engine with no boost.
Boost is the last thing you want on any engine. In an ideal world you want to use the least amount of boost possible to make the most amount of power over the widest rpm range.
But as engine size is limited, we are forced to use things like turbochargers to make the extra power we want from those small engines.
So what you really want is a bigger capacity engine, a small-medium sized turbo running moderate boost and highish compression to give a very responsive setup with a wide spread of power.
You absolutely do not want to run 44psi.
Of course the other option and it would be more expensive, but give a wide spread of power and instant throttle response to feel like a larger engine. Supercharge it.
25-09-2012, 10:19 PM
#33
Zee Germans are coming
Fuck it mat
Wind it up
If it goes bang so what just build another
Well that's what I did in my series 2 many years ago and it was the best afternoons driving I've ever had
Wind it up
If it goes bang so what just build another
Well that's what I did in my series 2 many years ago and it was the best afternoons driving I've ever had
25-09-2012, 10:20 PM
#34
There is nothing confusing about it.
26-09-2012, 09:53 AM
#36
Boost is never static. It is always rising/falling whether you can actually see it or not. That's why the wastegate is always varying it's opening. Again, it isnt a simple open or closed as it regulates flow in order to regulate boost.
There is nothing confusing about it.
There is nothing confusing about it.
You said inlet pressure rises but boost stays the same.
This is what I said was confusing as 'boost' is just differential pressure between atmospheric and inlet.
and breaks things 