The gains listed by Randy Webb and by Graham for the GRS and the gains claimed by Alta and Randy Webb for the Alta intercoolers are impressive and seem to be appreciable gains in both hp and torque. However, there are many who say that the stock intercooler is optimized or best suited to the MCS and no difference would be noticed by changing to a larger intercooler for most applications. For a daily driver that would see a little (not on a regular basis in any of the following ) autocross, road track, and 1/8 -1/4 mile time, is this a mod worth doing? Any real world experiences with the larger intercoolers and opinion as to there worth? My car is a 15% pulley, etc. car.

 

That could be a BIG "etc."...

Is it "etc." as in ported/relieved Cosworth Head, Cam, ported & polished SC, intake manifold, headers...

Or is it "etc." as in catback & intake?

 

The car is a more typical modified MCS: 15% pulley, CAI, catback, GIAC, plugs and wires. Under consideration is the intercooler and/or 2 or 3% plus crank pulley.

 

The dyno graphs seem to show the differences quoted, so my guess would be that the changes seen would in fact be carried over into the real world. But, it should be said that a car on a dyno sees higher intake temps than one that is actually travelling because the one which is moving sees more airflow. The difference in the 'real world' may not therefore be that huge.

 

In your case-
2% or 3% crank pulley - put that on hold until others have done more testing on it. If it checks out good you can always add it later.
Larger intercooler- here's the concern. For $800 you can get maybe 4-6+hp, with GRS maybe a bit more. It's hard to test well but mostly we see that the larger intercooler does a bit better than stock until it gets heat soaked. Then the efficient cooling of the stock IC works better. It can become a wash as the car gets heated up more.

I think there are other mods that could be helpful to you. But they might cost more.

Quaife differential- excellent albeit expensive. Keep the stock flywheel and clutch for max street driveability. Helps you put your "power" to the ground

Coil overs- smoother ride, adjustable for street or performance driving. Check out Bilstein PSS9 about $1540 at Helix13.com on special now. Adjusts ride height and can set dampers on all four corners very easily.

Lighter rims and sticky tires.

All three of these mods are big impact mods.

 

MINIHune, huh? Not doubting you, but I don't follow what you're saying. I went over to Randy's site, and I don't see any info that shows the stock i/c working better: http://store.webbmotorsports.com/ind...5dabc1e8f35fd2

The thoughts you posted are helpful, just want to make sure I understand them.

 

It seems like you are starting down the "more" path... This can get very, very expensive without a final goal in site.... So, without knowing your target...

Real tires. Better handling, better braking, better everything. Choose the tire based on what you want to do with your car.

15% Pully. Just cause it should have had one from the factory... This also means cooler plugs.

Intake. Easy to do. Easy to undo too!

Rear Sway Bar. Should have come from the factory that way as well.

Caliper bushings. Make the existing brakes work much better.

Now, things open up. Exhaust can free power, and lose weight too. Lighter wheels help in lowering unsprung weight for better handling. Brake kits improve stopping, and can lose weight as well. You can throw money at nitrous (1/4 mile), Cosworth, twincharge whatever....

Before you add, figure out the goal. Then add parts that you can afford that progress you towards the goal!

Matt

oh yea, back to the thread. I have an Alta TMIC, and it definantly helps. I bought it used.... Keep in mind that you will have restricted access to the spark plugs. The Alta is bigger. I haven't seen the GRS in person, but I like htat it uses the mounting bosses. The Alta just rests on top of them. I think the Alta air diverter could use some work as well.... Anyway, you're talking a bit less than a kilobuck, so I'd spend the money elsewhere, on handling. If you can carry more speed, you don't need the HP as much.,..

-M-

 

if tested on a dyno, I would doubt any hp claims for various intercoolers relate to a moving car. for these reasons:

compared to the lightweight stocker, a more thermally massive intercooler (whether by sheer metal mass or a water jacket) will initially be able to remove more heat from the airstream, so for a short dyno pull, it will lower the IAT more and produce a higher hp reading.

creative fan use notwithstanding, the in vitro use of the dyno comes nowhere near simulating normal airflow through the IC. until an IC comes along that does not rely on vehicle speed to dump heat, staitic tests are bogus.


what is useful data is comparing IAT for various intercoolers on the track, assuming conditions can be normalized: same car, same ambient, same load condition, same degree of jheat soak, etc. good luck.

 

Some of this should be answered with some basic informaiton:
What is the pressure drop across the stock IC vs the aftermarket units?
The difference in surface area?
Anyone done thermal drop testing?

I would imagine there would be no real gains to be had with stock boost or a slight increase.. At least from a cost to performance ratio... but for the guys running 19%+ reduction and see prolong periods of boost... a good IC upgrade would be a key mod..

 

The stock intercooler works under all conditions reasonably well.

You can upgrade the intercooler and it might help a little but when it gets heated up it might not cool off fast enough to be of any advantage over the stock intercooler. It all depends on how hot it is and how hard you are driving. It's not a cheap upgrade so be aware there are limitations with any mod to the intercooler.

 

Get a better scoop to stuff more air over your existing IC, then take the rest of the money and send it to me! Uh, buy other parts.... You can always as a bigger IC later, but it is a pricey adder.... There's so much out there that costs much less. Think, a cam is less! (not counting installation, I know).

do what I did, troll the marketplace until you find one for cheap then jump all over it!

Matt

 

I added the Alta after all the other engine mods and it helped a lot. I live in GA where it is hot and humid. No dyno data but this butt dyno and the butt dyno of my mechanic are very pleased. I'm not sure what gains I would have noticed before the head/cam etc.

 

I have the alta and I can tell you that driving at "speed" there is a difference between the alta and the stock one. I did a swap and ended up leaving the stock ic on for the ride home, there was a noticable difference in responce and overall crispness. I cant tell you what temps were or hp #'s but there is definitly a difference. I doubt its much on a dyno or just cruising but at speed its noticable. The car pulls harder longer!

 

detlman,

I'm confused by your reply; the larger IC was better? Crisper? Or the stock one?

Minihune,

I've been told just the opposite regarding a larger heat-soaked IC; if I understand, more surface area = more cooling efficiency. In other words nearly impossible to gain as much heat as the stock IC??? I know there are other factors such as pressure and core shape that can change the outcome...and I am far from knowledgable in this area.

I like jlm's approach to this confusing subject; it's like wheel hp, it won't lie.

 

Yes the larger one felt better.

 

Thanks

 

Hi Len,

I was the pesky DS/B MCS at Wicks.

On the Monday following Phil Wicks, I installed the GRS. I had hoped to get it before the event, but alas it came while I was away in a meeeting Friday before leaving for Talladega.

The GRS is beautifully finished with eye-popping weld quality. The inner core is amazing compared to the stock unit. When it's installed, and you look into the scoop, you can see the top surface of the GRS just at the same level. The unit is larger than the stock unit. Once installed, you won't be changing spark plugs without first removing the IC.

As you know, it's been pretty warm here in Georgia. So I expected a nice improvement in performance. And the performance IS better.

But I'd have to say that the difference is a bit underwhelming. It's probably true that my expectations may have been a tad too high...

Would I spend the money now that I know what the outcome would be? Frankly, I'm not sure. Might, and might not. Guess time will tell.

Are coming to the MINI auto-x day on July 9 here in Hotlanta?

Pete, Scott and a bunch of us will be there. You can see and maybe drive mine and at least get first hand experience.

 

[CLIFFCLAVIN] The First Law of Thermodynamics states that energy is conserved. For our purposes, this means that heat that goes into an intercooler must be removed to somewhere and cannot magically disappear. We can also consider that heat is continuously being put into the intercooler and removed; that is, there are input and output rates, as well as a steady-state equilibrium temperature. If the rate-limiting step is not the surface area of the intercooler but the amount of air that makes it past the little scoop thingy, then you can see that even making the intercooler the size of the hood would not improve things, for the input heat is exactly the same and the possible output is the same (limited by airflow). More mass in the system means maybe an extra minute before things stabilize to exactly the same temperature. It also means it takes an extra minute or so to cool back down once boost (heat input) is removed or airflow resumes (stop and go traffic). So it only delays the inevitable, and not by a lot either because the specific heat capacity of aluminum is 893 J/Kg-K. This means it only takes 893 Joules of heat to raise 1Kg of aluminum by 1 degree Kelvin in the absence of airflow. For reference, 1 Cal=4168J so we are talking less than a quarter Calorie of heat here and 22 Calories=100C degree rise. Water has by definition a heat capacity of 4168 J/Kg-K so it will have far more inertia, especially since there will probably be more water by weight than aluminum.[/CLIFFCLAVIN]

jlm is right; nobody really runs a car on the dyno long enough to be sure the intercooler has reached equilibrium, and nobody has purchased a powerful enough fan to simulate speed either. Top speed testing would work but I suspect most people want to know how the product performs in their intended use (low speed track or daily driving).

 

Well, I have. I've posted the photo below once before and we also did a test a year ago comparing a stock IC and my Alta, though it was completely un-scientific.

When M-7 came out with their hood scoop, I jumped on it and with some slight mods it became a great match up for my Alta IC. I’ve also spent some time 'cleaning up' behind (under) the IC by removing anything that was not absolutely needed and re-routing any wires or hoses.

I have no real test numbers to show, but someday I will try. My car dynos quite well and runs very strong on the track. I'm personally sold on the larger IC and do all I can to feed it air,

 

Hey Jim,
Who did the work on your car?

I live in Columbia, SC and dont have any one here. At least not yet.

Thanks
Jack

 

I guess there are so many if, ands, or buts with regard to how efficient an IC can be. I've talked with so many people, I've PM'd a few and as you might expect, I received as many opinions about the merits of a larger IC.

I agree with your thoughts regarding a larger IC, and, more air flow - not because I understand the science intimately, but because it makes sense. In fact, this is exactly what Onasled wrote in a PM to me.

I believe that common sense would lead most of us to expect an improvment in hp with a larger IC , and, more air flow. What the actual hp improvement is, is defined by variables such as weather, and driving venue???

I'm simply interested in building a safe, thermally efficient motor capable of providing reliable - accessible hp when I want it. I want to eliminate as much of the hot/humid lazy response from the engine as possible. Cooling things off 'feels' like the right path for me. The cost trade-off is indeed personal.

 

I don't do much wrenching at all. A friend helped me. It's not rocket science. Takes about 45 minutes or so.

 

Thanks to all for your comments. I have a MCS with the engine mods mentioned in my second post above - pretty typical stuff, have some suspension mods, wheels and tires (Toyo), shortshifter, and I am bit by the modding bug and looking for the next most sensible addition to the car. In a purely unscientific sense, as several above have mentioned, the larger intercooler seems attractive, as it would seem to not just add hp/torque (if the claims are accurate), but add in a safer way in terms of engine longevity, etc. I admit to a limited understanding of pressure drop issues and other technical stuff, and while I believe I understand issues of real world vs. dyno related results, I am just looking for a good return on my investment, not a waste of funds that could be directed elswhere - MINI related or not.


Jim: I was attracted to the GRS as well, and look forward to seeing you at the autocross event in Atlanta. You weren't pesky - I was just in your way!

Len

 

Hi Jim,

So you got the GRS....congrats...see you on the 9th.

 

Good work onasled! Only problem I see is trying to correlate the fan output with a particular roadspeed, as in "through the hoodscoop". Can you imagine having a (smaller) fan on there all of the time to keep the intercooler from heatsoaking when idling?

My suggestion was that if airflow to the intercooler was rate-limiting, efforts should first be made to improve that before considering a larger intercooler. There is no doubt that a larger intercooler would work better given enough airflow, and I agree your efforts to improve that should be useful.

I was trying to point out that a larger IC does not necessarily equate to cooling things off. In fact the extra heat soaked up in prolonged idling would actually take longer than stock to dissipate once underway, leading to lazy response in stop-and-go traffic. More mass buys more thermal inertia and this cuts both ways.