45mm runners (GTA,164QV)

Yes, 45mm, but your Q4 probably has this already.

Picture below:

Yep

It does indeed say that -- . I have been wondering for some time now the reproducability and reliability of those claims though. Not to say that I think anyone is trying to pull a fast one, but as far as I know, there has been no other controlled experiment on both the runners and the chip (I have the chip installed in one car only). Without having the test protocol in hand, and the test report in full, along with the details about the car under test,the dyno used, etc etc its hard to put 'too much' stock into the claims--- kind of like the ole K&N/paper filter arguments, synthetic vs dino oil, and my favorite, the 'dream away' weight loss pills (remember those-- Classic!). As a researcher, I can spin data lots of ways to make my point--- as long as you don;t ask to see under the hood, so to speak. Was it one dyno run? Same gas? Same car? etc etc


Not meaning to be a skeptic, but thats my educational and occupational training. I installed those runnners with the expectation that the low end would be about the same or marginally better-- but the seat of my pants tells me that maybe that aint the case.

164 FAMILY said:

I thought the Q cars had 44mm on them that is why I asked? I would love to put some new ones on it.

Click to expand...

All 45mm on Q/QV/Q4

I have sets of new ones lenard.


I understand what you are saying Goats but here is one thing we need to put into the equation, transmissions.
I think Stephen (from memory) used a 5 speed Super which has a slightly different gearing than the Qv or (Q and Q4), so I think the numbers will not match exactly using a different transmission. I am not sure an Auto could make those numbers to be honest, they can come close but more in the higher RPM.

As far as I know the runners are the only difference in the 2 motors. ECU, cams, pistons, AFM (or MAP for Q4) , wiring harnesses etc and so on are all the same.
I think for the most part you do get the "claimed" 19-20 extra hp from the runners.

So the numbers are going to be off a bit. If you slapped a Q transmission on there the numbers might match.



J

Everybody feels something different in their cars. That's ok.

We do know, as Jason says, that the only difference between the LS and Q engines is the intake runners. We also know that the two engines are rated as about 20 hp difference. So...we do know that the runners do make a difference, nobody disputes that. Unfortunately, the Squadra test is the only one I've seen for just a runner change, so there is no backup information other than what the factory would say, but I've not seen Factory charts for the same change, ie, published hp/torque charts for the two engines. Of course we do know that in some circumstances, installing too large an intake system will affect low end torque, but I don't think this is the case with the LS just being a choked down Q engine.

My own feeling and experience driving the LS, and with the comments of my dealer who has also driven the car before and after the change, makes me believe the Squadra charts are reasonable. The LS as it sits now has not suffered at all at low speeds, and definitely feels peppier at passing speeds on the highway. I'm quite happy with it.

Goats, I don't know what would make your car feel different.

Agree about variable intake lengths, and variable cam timing.

Grant I think thats what would happen!

My experience is that the HP gain at high RPM is legit and noticeable. Once I get the cars above 3800 or so it just kicks on with the larger runners, I truly believe there is a 7-10 hp gain -- and maybe something like the 15-20 claimed -- all I know is its got more power with the bigger tubes at higher RPM for sure

I suspect that what happens is that at low rpm, we have relatively low Reynolds number, and somthing closer to plug /laminar flow, which in my view is not the best arrangement. With the smaller runners, the velocity is increased, and as a result we get a little more turbulent flow, resulting in a more uniform mixture, a tad more intake pack, and who knows what else.

As RPM gets up there, we revert back to more turbulent flow -- but not too turbulent and therefore less lost energy, etc.

Its probably tricky to get everything dialed in as for most, its a matter of compromise!

Jason, yep agree at higher rpm its good -- Del I agree too that mileage is a tad better perhaps with the larger runners at cruise speeds---

From my aircraft engine design classes in college, It was critical as to what the intake dia, ie, potential mass flow, was in comparison to cylinder volume, valve size, piston speed, and cam timing, etc. If the mass flow velocity into the intake is too low, esp at low engine rpm, then the amount of air crammed into the cylinder during the intake stroke before the valves slam shut is reduced due to lower momentum of the incoming charge, allowing some of the charge to be forced backward out, or at least stymied in it's flow as the piston rises. There is a supercharging effect in these designs.

I had this illustrated to me quite clearly with my old Downton prepared Cooper S mini. The larger intake (1 1/2 inch carbs instead of 1 1/4 inch) and the AEG 648 cam resulted in mixture being pushed BACK out of the intake (onto the firewall) at below about 3000 rpm. Then, as that rpm was exceeded, the velocity was sufficient to keep the charge in the cylinder when the cam closed the intake valve, and away we would go.

Friend of mine raced a 1300 Giulia Sprint Coupe Veloce which had an engine which was soooo "cammed" that it wouldn't run worth a **** below about 4500 rpm (seemed like about 5 hp), but had a shift point of 9000-9500 rpm, with an idle of about 2500 rpm. Really difficult to drive except in a race, but oh so fast.

Bottom line for my feelings is that the LS engine with the Q runners does not fall into that regime being just a choked down Q.

Del said:

From my aircraft engine design classes in college, It was critical as to what the intake dia, ie, potential mass flow, was in comparison to cylinder volume, valve size, piston speed, and cam timing, etc. If the mass flow velocity into the intake is too low, esp at low engine rpm, then the amount of air crammed into the cylinder during the intake stroke before the valves slam shut is reduced due to lower momentum of the incoming charge, allowing some of the charge to be forced backward out, or at least stymied in it's flow as the piston rises. There is a supercharging effect in these designs.

I had this illustrated to me quite clearly with my old Downton prepared Cooper S mini. The larger intake (1 1/2 inch carbs instead of 1 1/4 inch) and the AEG 648 cam resulted in mixture being pushed BACK out of the intake (onto the firewall) at below about 3000 rpm. Then, as that rpm was exceeded, the velocity was sufficient to keep the charge in the cylinder when the cam closed the intake valve, and away we would go.

Friend of mine raced a 1300 Giulia Sprint Coupe Veloce which had an engine which was soooo "cammed" that it wouldn't run worth a **** below about 4500 rpm (seemed like about 5 hp), but had a shift point of 9000-9500 rpm, with an idle of about 2500 rpm. Really difficult to drive except in a race, but oh so fast.

Bottom line for my feelings is that the LS engine with the Q runners does not fall into that regime being just a choked down Q.

Click to expand...

Here is the deal.
The difference between the motors as we have established is the runners.
ECU, AFM, Cams, Pistons, exhaust system and so on is all the same.
LS is just detuned to 210hp using a 39mm intake runner. The bottom plates and intake plenum are all 45mm.

LS transmission and the obvious are the only differences.

I think that the problem here is that your so use to the LS and when you upgraded to the Q runners it made a drastic change that you expected the Q runners to pull all the way through the band.
Well that's not the case(maybe I am not understanding the conversation either and if not my apologies).
The Q has a very weak low RPM, which is very similar to the OLD Q, the S.
The L is very similar to the LS in characteristics in that it has great low end torque and power and a little weaker higher up.
L transmission and LS transmissions are exactly the same where as the S and Q are exactly the same. This is the same reasons you see the difference in HP between them, even though the 12V S had higher compression and different cams, on that motor that is the difference between (exhaust,e cu afm etc.. )them for the most part.

My point is that Alfa made the 24V the same all the way through. Spending less money on different pistons, AFM's, exhaust, etc and just detuned the car with smaller intake runners and the different transmissions (except for LS SCS version, same as Q) and trim levels.
Both cars except for AUTO weight the same

I think that if you are not driving a "true" Q everyday you don't have the real feel for the car if you catch my drift? There is only a 4 ft/lb torque difference between them.
Driving a LS then upgrading to the 45mm intake runners does not give you the full Q feel. It for sure is a huge upgrade and makes a dramatic difference but again there are just minor differences between the cars.



Anyways, I think that the 45mm gives the LS the Q characteristics although the tranny can make it feel a bit different, not that the LS transmission is not good by all means it is.
Ok, let me know if I am off my rocker?

jason