Definitive solution for M12 intercooler
Discussion
But with a bigger internal volume of intercooler you cannot have the same lag as the volume of air in the intercooler that has to be compressed is greater which will take longer, therefore it takes longer between opening the throttle and compressed charge to reach the inlet manifold.
obes said:
Exactly, having a bigger intercooler is like having longer charged pipework.....more lag.
Matt's soultion works because the intercooler does what it does better without introducing larger volumes.
strange but on the M400 with this intercooler doesn't work as you tell.
the car as no lag!
Dear All,
My analysis;
If the italian one is 2.5 x larger it has approx 2.5 x as much material and thus weight and the machining costs are bound to be increased and there's the weight of the 4 fans. I don't know how much the italian one will cost.
Alternatively there is the John Noble Motorsports IC upgrade - about which I know little other than the price - £999 fitted.
Matt's soultion is cheaper than the JNM IC and Matt's gets you the fan and the temp sensor as well and is undoubtedly lighter and higher tech - a more subtle and scientific approach. In theory it should improve throttle response and reduce turbo lag - even if in practice you can't notice it.
Either way you've got to pay to upgrade - just choose what to pay for - more alluminium or better technology.
Regards
Paul C
My analysis;
If the italian one is 2.5 x larger it has approx 2.5 x as much material and thus weight and the machining costs are bound to be increased and there's the weight of the 4 fans. I don't know how much the italian one will cost.
Alternatively there is the John Noble Motorsports IC upgrade - about which I know little other than the price - £999 fitted.
Matt's soultion is cheaper than the JNM IC and Matt's gets you the fan and the temp sensor as well and is undoubtedly lighter and higher tech - a more subtle and scientific approach. In theory it should improve throttle response and reduce turbo lag - even if in practice you can't notice it.
Either way you've got to pay to upgrade - just choose what to pay for - more alluminium or better technology.
Regards
Paul C
I think JNM's intercooler is a larger one(wider not thicker). I don't know if it has the same or similar construction technology to Matt's one.
Sprays are probably cheaper but can be a bit of a pain, water ones or liquid nitrogen bottles need to be re-filled to start. Then there's the question of how and when you fire the spray, some kind of control system has to be put in.
I think a thermostatically controlled fan on a small efficient intercooler has got to be the way to go.
Sprays are probably cheaper but can be a bit of a pain, water ones or liquid nitrogen bottles need to be re-filled to start. Then there's the question of how and when you fire the spray, some kind of control system has to be put in.
I think a thermostatically controlled fan on a small efficient intercooler has got to be the way to go.
l6nex said:
I know this might sound daft but on a skyline R34 GTR I looked at they had a little spray system that sprayed NOS directly onto the IC which led to Freezing the air passing through it. Could this be a easy solution???? or is it a daft Idea.
Dave
It works well and is easy, it is a method of achieving OVER 100% efficiency of an intercooler. It is usually only used on cars that are for drag racing or top speed runs as the bottle/bottles don't last too long. A great solution but maybe not for this application. People also use water/air IC with an ice tank to cool the water used to cool the IC. Works great for a few minutes.
l6nex said:
I know this might sound daft but on a skyline R34 GTR I looked at they had a little spray system that sprayed NOS directly onto the IC which led to Freezing the air passing through it. Could this be a easy solution???? or is it a daft Idea.
Dave
forget it!!
the ONLY solution is the big intercooler!
2.06 min. at MONZA are enought to understand what i mean!!!!!
other solutions are acceptable for kart circuits!
jmg944t said:
I know this might sound daft but on a skyline R34 GTR I looked at they had a little spray system that sprayed NOS directly onto the IC which led to Freezing the air passing through it. Could this be a easy solution???? or is it a daft Idea.
Dave
It works well and is easy, it is a method of achieving OVER 100% efficiency of an intercooler. It is usually only used on cars that are for drag racing or top speed runs as the bottle/bottles don't last too long. A great solution but maybe not for this application. People also use water/air IC with an ice tank to cool the water used to cool the IC. Works great for a few minutes.
NOBLE is not a drag racing car but thebest circuit car!!
that's a little bit different!
if you want do drag racing you don't do anything!
if you want do 10 fast laps in spring you need a large intercooler!
m12_nathan said:
A bigger intercooler introduces more lag unless you live on a different plannet with different physics to the rest of us, the Nurburgring makes Monza look like a kart track and there are plenty of better circuit cars than the Noble.
End of thread
That's not completely true. Lag time is also influenced (more influenced, by some accounts) by airflow restriction, which comes down to core design. An easy way to think of it is a 10' straight pipe that's 2" in diameter will have less restriction, and thus less lag, than if that same pipe had many sharp bends.
If we normalize for design, we still come back to the question of HOW MUCH lag the bigger intercooler will cause.
Here are my thoughts (and feel free to correct me if I'm wrong):
The stock Noble intercooler core is:
451mm X 254mm X 50mm = 17.76" x 10" x 1.969"
Typically, a tube & fin type intercooler has an internal tube volume of just under 1/3 the total external size. We'll use 1/3 to make it simple.
We'll also ignore end tank measurements for now, again just to make it simple. Yes, end tanks definitely matter, as does tubing.
17.76" x 10" x 1.969" = 349.69 cubic inches, external volume
349.69 x 1/3 = 115.4 cubic inches, internal tube volume = 0.0668 cubic feet
From before, in choosing an intercooler, a rough rule of thumb is 1.5 times your peak HP gives you airflow in CFM's.
360hp x 1.5 = 540 CFM's = 9 cubic feet per second
0.00668 / 9 = .00742 seconds = time it takes for our engine to fill this intercooler to 1 atmosphere.
Now to pressurize it to .6 bar (ambient + .59 atm), it would, of course, take longer. Even if we say, worst case senario, it takes 3x as long, we're still talking about .02 of a second.
Looking at the intercooler 2.5x this size:
.00742 seconds * 2.5 = .0186 seconds to fill intercooler
.0186 x 3 = .056 seconds lag time, worst case
So, a 2.5x size intercooler gives a .036 second additional lag on a standard GTO-3R. On the M400, the difference should be roughly equivalent, since it has higher CFM's, but also has to pressurize to .8 bar.
The question is...
Is your rear end calibrated enough to feel a .036 second difference in lag?
gotapex said:
360hp x 1.5 = 540 CFM's = 9 cubic feet per second
Some food for thought :-
What about at say, 3,000RPM when we're nowhere near max power. Isn't the airflow going to be much less? Isn't it at low airflow times we're really going to notice the lag anyway?
Just theory here so I'd be interested what people think...
gotapex said:
The question is...
Is your rear end calibrated enough to feel a .036 second difference in lag?
My rear end certainly isn't, but the transponder on a race car and accompanying timing gear is.
10 lap race, 7 corners per lap, lets say you lift for 6 of them.
6 X .036 = 0.216 seconds of lag per lap
0.216 X 10 laps = 2.16 seconds of lag
Now remember the above doesn't take into account the start and assumes the entire race is driven in one gear and that you only lift and decel for each corner once.
Obviously we can run around with this all day, we've not even talked about the increased drag an increase in number of cooling tubes would cause, but hopefully the above makes it clear just how important minimising turbo lag is, a very very very small amount of lag can become rather significant under certain conditions!
Best Regards
Matt
Isn't turbo lag more complicated than that? It's essentially a feedback loop and the initial transient (opening the throttle) may (will) have to 'go round the loop' several times before the output (net torque) settles. Turbo lag is going to depend on how much the system responds to a change in the input conditions (if your turbo shoves in 110% of what the engine has taken out of the inlet manifold, how much does the manifold pressure go up by?) as well as how long it takes for the output to change afterwards (two crank revolutions plus other delays).
If you increase the volume of the inlet manifold you're reducing the 'gain' of the system and increasing the number of iterations it will take to respond. Gut feeling is this would make the system very sensitive to inlet manifold volume.
Here the change in the inlet manifold seems relatively small, but is it enough to matter? I don't know enough to predict, but empirically the answer seems to be that it doesn't.
If you increase the volume of the inlet manifold you're reducing the 'gain' of the system and increasing the number of iterations it will take to respond. Gut feeling is this would make the system very sensitive to inlet manifold volume.
Here the change in the inlet manifold seems relatively small, but is it enough to matter? I don't know enough to predict, but empirically the answer seems to be that it doesn't.
I would be very interested to hear what Noble would have to say on this and or Rousch - But I would think they probably are not going to comment as we all know the factories stance on modifications (Fair play to them as well). However I'm very intriguiged as my car is well out of warranty.
We seem to have discussed Intercoolers fairly well, now how about trying to make the exhaust system more free flowing - I don't know about anyone elses but mine has always been very badly fitting and has more kninks and turns in it than my own gut!
(It even has had a fine tunning tool applied to it to make it fit around suspension mounts!). I'm sure a freer flowing more straight through exhaust system would reduce lag. I'm under the impression - and correct me if I'm wrong but larger the difference in size between the input pipe (to the compressor side of the turbo) and the exit pipe (ie if the input pipe is say 2" and the exit pipe is 4") the faster the turbo will spool up, or to put it another way the less back pressure the better. Plus does anyone know if the pipes from either set of cylinders are of equal length?
More food for thought.
>> Edited by gizard on Wednesday 23 February 08:03
We seem to have discussed Intercoolers fairly well, now how about trying to make the exhaust system more free flowing - I don't know about anyone elses but mine has always been very badly fitting and has more kninks and turns in it than my own gut!
(It even has had a fine tunning tool applied to it to make it fit around suspension mounts!). I'm sure a freer flowing more straight through exhaust system would reduce lag. I'm under the impression - and correct me if I'm wrong but larger the difference in size between the input pipe (to the compressor side of the turbo) and the exit pipe (ie if the input pipe is say 2" and the exit pipe is 4") the faster the turbo will spool up, or to put it another way the less back pressure the better. Plus does anyone know if the pipes from either set of cylinders are of equal length? More food for thought.
>> Edited by gizard on Wednesday 23 February 08:03
gizard said:
We seem to have discussed Intercoolers fairly well, now how about trying to make the exhaust system more free flowing
......errr watch this space. Does my car have a load of Janspeed components in the passenger footwell waiting to be welded up? - yes
gizard said:
Plus does anyone know if the pipes from either set of cylinders are of equal length?
Yes, I do, they are of equal length.
Regards
Paul C
m12_nathan said:
A bigger intercooler introduces more lag unless you live on a different plannet with different physics to the rest of us, the Nurburgring makes Monza look like a kart track and there are plenty of better circuit cars than the Noble.
End of thread
i think you are talking without experience!
that's it!
the experience that i have!
re-end of topic!
Hy everybody!
I post my contribute, I'm the driver of the Noble here in Italy and I've been the tester for all the modifications.
I had 3 Nobles: a 2,5 a 3R and now the white M400 (you saw the pics 2 months ago...) allways a lot of trouble in Monza for hot temp of the intercooler and in consequence a cut off of power.
The m400 even in winter in Monza had before the modifications a lot of problem of power lost for high temp. we never lapped under 2.10.
After the modifications we now lap continuatively in 2.06/2.07 and I'm not a professional driver...
It's a very impressive time because has been done with a car completely normal apart the new intercooler with fan, Etcc car like Bmw driven by professional driver has done the pole last year in 2.07....
I really don't feel this delay of reply in the throttle, and I think that is better to have a bit of delay but lapping 3 or 4 sec below!
For who say that Monza seems a Kart track instead of Nurburgring...I've lapped many times at the nurb, and it's a very nice place, but please don't call it circuit! Cayenne at the nurb in a circuit of 8 min. lap only 30 sec slower than a carrera Gt, in a real track of 2 mins it takes 20 sec....Nurb is a fantastic place where testing and developing a car, but not a veritable circuit, even if I love it...
The only thing to do is trying all the modifications on the same track and looking which will be the better one...if somebody will pass from Monza let's tell me, bye
Marcello.
I post my contribute, I'm the driver of the Noble here in Italy and I've been the tester for all the modifications.
I had 3 Nobles: a 2,5 a 3R and now the white M400 (you saw the pics 2 months ago...) allways a lot of trouble in Monza for hot temp of the intercooler and in consequence a cut off of power.
The m400 even in winter in Monza had before the modifications a lot of problem of power lost for high temp. we never lapped under 2.10.
After the modifications we now lap continuatively in 2.06/2.07 and I'm not a professional driver...
It's a very impressive time because has been done with a car completely normal apart the new intercooler with fan, Etcc car like Bmw driven by professional driver has done the pole last year in 2.07....
I really don't feel this delay of reply in the throttle, and I think that is better to have a bit of delay but lapping 3 or 4 sec below!
For who say that Monza seems a Kart track instead of Nurburgring...I've lapped many times at the nurb, and it's a very nice place, but please don't call it circuit! Cayenne at the nurb in a circuit of 8 min. lap only 30 sec slower than a carrera Gt, in a real track of 2 mins it takes 20 sec....Nurb is a fantastic place where testing and developing a car, but not a veritable circuit, even if I love it...
The only thing to do is trying all the modifications on the same track and looking which will be the better one...if somebody will pass from Monza let's tell me, bye
Marcello.
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