I appreciate the response, and i think it answers my question, unfortunately I have to admit that I'm not sure what Lam is, so I can't be sure.

 

Love those moon discs Mugami when you hitting the salts

 

[quote=Mugami]


It would seem if GTT just put tabs like GRS and Forge to hold the IC in place (front stock screw holes) that your problems of sliding left/right as well as rubbing could have been avoided.

 

That makes sense to me too. Just have the brackets extending forward from the center of the leading edge of the IC.

 

I have a question for those who know - is it possible that an IC be too big?
Or is the theory bigger is best when it comes to IC.

Alta is 40% bigger and the GTT is 55% thats internal volume.

 

Yes, assuming that the surface area was growing less than the internal volume was, it would then have the issue of heat soak, where it gathers lots of heat but can't transfer it. [Remember from geometry how, as shapes grow, their inside volume (a factor of three dimensions) grows quicker than surface area (a factor of two dimensions)?]. Cooling can only increase with increasing surface area.

 

So its not enough to know internal volume when looking at intercoolers.

Alta is 100% bigger (to stock) offering 40% increase internal volume.
GTT is X% (couldn't find data) bigger offering 55% increase internal volume.

If I understood you correctly - assuming that they were both the same size externally then the GTT should be more efficient as an intercooler. Which means that for the GTT to perform equally to the Alta it would have to be 137% bigger. Less more efficient, bigger less efficient.

 

One looks bigger than the other or is it just me? Look where the front of my Alta ends up compared to the bottom image.

 

The greater the proportion of surface area to volume is, for a given volume, the higher the rate of thermal dispersal. SO, if the Alta and GTT have the same surface area, but the volume is higher in the GTT, you can expect the Alta to work better. If the GTT has a larger surface area AND the proportion above is higher, it should cool better, assuming the same air flow characteristics and metal properties.

 

The Alta uses of the front stock attachments bringing more forward. The GTT starts behind the stock attachment but appears to go back farther. The GTT gives you a plate to relocate the coil were as the Alta seems to fit with the stock coil position.

Another thing I notes, it appears that the GTT is more angled, perhaps its an illusion. If you notice the diverter is on the sides and tapers off. None on the back however the website does reference a 3 piece diverter perhaps its off on the picture or I'm not seeing it. When I look at the pictures and compare to the left horn the GTT does seem to sit up in the back. Assuming that both seal equally well this angle should be a positive from an air exit point of view.

 

I just love the way my GRS looks and works.Check out my Gallery. If you don't like "bling" under the bonnet don't look. It installed like it was meant to be there.No extra work was needed to make it fit.Graham really does a fantastic job.

 

The Alta is not attached to anything except the bellows. The front edge of the IC meets up with the opening of the intake and the rear just hovers over the spark plugs requiring it to removed to access the plugs. The two photos appear to be about the same angle and the rear of both looks to be extended back the same amount. If that's correct, then the Alta distinctly has greater surface area. But to settle this, I'll measure the dang thing tonight and post the dimensions...

One curious thing with the GTT image...where is the rear seal?

 

Rear seal must be on the bonnet like the GRS.

 

Hey cycleguru, WOW love the details under the bonnet! Great looking car. I have an off-topic ? for you. I notice you have gauges in the cup holder areas. I've been thinking of doing that too. What brand/size gauges did you use, and was it a huge hassle to install them in those spaces?

Ken

 

Its tough to really "see" the differences. Angle wise, it seemed to me that the GTT had more angle but perhaps its the Alta Diverter playing tricks on my eyes. I'll PM the GTT owner to see if we can get a measurement as well.

The GTT webiste does say 3 piece diverter - I figure the back piece was off the car.

 

I really like te GRS and your gallery pic is . I particularly like the diverter set-up they did. As I research IC, I think that any one - alta, grs and gtt would be fine choices and clearly a step up from stock. I leave Forge at the back of the line - sticks up in the scoop and no diverter.

At then end of the day it will most likely boil down to price for me.

On another note funky guages - very cool.

 

Thanks Ken, It was really pretty easy to mount them in the cup holders. One of our NAM members gave me the idea. I wish i could remember who it was to give him credit.The gauges are Auto Meter.They are from the phantom line. The size is 2-5/8. They fit a little loose when you first slip them in But what i did was wrap some elctrical tape around the gauge and made them fit snugly. Maybe about 4 or 5 times around.Thats how i got them to angle towards me.They don't move at all. So i found no need to bolt them down. The wires were easy to run up by my pedals.Good luck Ken.

 

Yes...very nice detailing

 

Alta Gen 1 dimensions: 10" deep x 1.5" thick x 15.5" wide

 

If i can find my mearsuing tape.. yes im looking for ill give it a measure. also since the important thing is the area where the air flows not only will i measure the outside demention but the demention inside the diverter.
As for the angle yes the GTT will have more This is due to the front sitting back behiind and below the front mounts while the Alta sits on top of them.

On the diverter its self mine was only a 2pc. and again was one of Rolands 1st gen prototypes. The back of the IC sits all the way up nearly touching the hood (bonnet) itself. If you noticed the black stuff on the corner of the IC. That was wear it was touching or got buried into the underlining of the bonnet. With this i didnt want a rear seal but perfer to allow the air to escape out of the back and direct along the back of the IC which increases the surface area that the cooling air is flowing over. the original intent Roland had was to use the Stock plastick Diverter/ liner which would act as the rear seal. Since it has to be modded to look like the Liner sent to you with the GRS IC. Personaly since i dont like the idea of a Plasitc (stock) or really the what appeared to be acryllic (GRS) liner not to have a ridged support for the back supporting bracket. Especailly since its going to be subjected to extreme temp changes of heating and cooling along with motor vibration. I just have the fear it can break the mounting tabs in the rear of the liner. That why for mine i removed the liner all together.

Also did a few personal grassroots by touch tests. no numbers no facts (sorry Andy) to confirm anything. When i first install the IC i did run a seal along the back along with the rubber piece in front so all the air was flowing across the center or finned only area of the IC. After i set course I touched the both the IC and the smaller horn over on the TB side. They were very very warm (could hold hand on it for about 10 secs). After removing the back seal and doing the same run. both the ic and horn was cooler to the touch. Then removing the front plastic so now the air is going all around both front back and center of the IC .. after the run i could put my hand on the IC and horn all day if i wanted to And have been running it that way ever since.

Going to give my house another looking over to find that Ruler to measure the IC.

 

ok found the tape.. Finned area.
stock 6-1/4 x 10-3/4 x 1-7/8
GTT 9-3/8 x 11-3/8 x 2-1/8

outside including endtanks
10-1/8 x 14-7/8 x 2-3/8

 

I'm not sute of the math here - so lend a hand.

I multiply all three numbers ?

stock 6.25 x 10.75 x 1.88 = 126.31
Alta 10 x 1.5 x 15.5 = 232.50
GTT 9.38 x 11.38 x 2.13 = 227.37

This can't be right ? If correct then the Alta is bigger than the GTT?

Alta numbers are 100% bigger outside and 40% bigger inside to stock.
If correct then the Alta is bigger than the GTT? On the other hand if GTT is 55% bigger inside and its smaller than the Alta on the outside then it would be in theory the more effective intercooler?

Okay, I thow myself on the mercy of the math wizards here to understand this.

 

For ICs, there are some things that are better than others.

1) Internal flow cross sectional area should be high. This makes pressure loss less (think big pipe vs soda straw). This also means that two ICs in parallel work better than the same two ICs in series.
2)Turbulator density: Higher improves efficiency but increases pressure drop. True for both the internal and external turbulators (fins).
3) Larger internal volume decreases throttle response, so it is possible to have too big an IC!

What this all comes down to is tha external dimensions of the IC aren't enought to predict relative efficiency. Also, IC efficiency is just a measure of temp effects, but pressure doesn't come into the equation. So you may have a very efficient IC, that hurts your power because of excessive pressure drop. Remember, its about how many molecules you stuff into the combustion chamber, and this is a function of both temp and pressure.

Making a rig to test these things would be a *****. Oh yeah, I already have a test bed, my car!

Matt

 

Please contact GRS or GTT, as the dimensions of the i/c is not the best way to compare these i/c's. I would botch the technical explanation, so let the people that manufacture them explain. It would be much more helpful for you.

Edit: Sorry Matt, I was 1 minute late with my post. What you said!

 

Well, it looks like you've got me beat in the thickness. Ha!...but wait till you see my next intercooler Nothing on this planet like it...and I'm not exaggerating oops...did I just say that?