How much power am I giving up by using a tube/fin IC?
 

Just curious. I chose the EVO IC because of its cheapness and massiveness, and I like tube and fin because it is light and cools VERY well, so it agreed with the goal of OEM reliability I had for the car.

So If I were to put my car on the dyno with my evo IC versus a bar and plate, what would be the power gain? I wouldn't give up the above advantages unless it was like 20+hp.

Its probably irrelevent. You don't see any "bad" intecoolers much these days. If its keeping your intake temps in check you are probably fine. Most Evos push more air though those stock than any Miata will.

I have yet to find a definitive "end all" answer to this. There's too many variables. The only way to really know the answer is to install one on your car, do a pull - then repeat with the other. Let us know what you find. ;)

Very true. I figure if they're good enough for an evo to make 350-400hp, they're good enough for my lil' 1.6.

All we need is for Stripes to send me one of his kits. ;)

I don't believe you'll see much difference.

From my understanding.
Tube/fine = lighter and less restrictive, cools fine
Bar/plate = heavier and more restrictive, cools more effectively.

Edited for you ;)

Wait I thought bar/plate was less restrictive but cooled worse than tube/fin.

I'm with you Tim, from what I've read:

Tube/Fin = Greater pressure drop; But greater efficiency & lighter
Bar/Plate = Low pressure drop; But less efficient than tube/fin & heavier

Some nice visuals
http://www.are.com.au/techtalk/intec...e%20and%20Fin?

Don't forget that the endtank and IC piping is important also ;)

yeah it's all stolen from Corky Bell, which is where I got my info from.... I can tell you the page number later when I get home.

Yeah, tube/fin cools really well because it is more restrictive. Charge air hits more fins and spends more time in the core. Bar/plate flows better/makes more power but doesn't cool as well and is heavier.

maximum boost pg 49, Fig. 5-4

you are giving up all your power by not using WI and relying on that laggy peice of metal :) j/k

I have an srt4 tube/fin, traded a precsion bar/plate for it, I like the lightness of it over the bar/plate, difference was prolly like 15lbs, thing was heavvvvvy.

That IC Is massive...How is your radiator cooling efficeintcy...Any overheating issues? Im just curious?

I've had no problems with overheating, but then I don't track it. I'm sure some ducting or a radiator from an automatic or a Koyo would be plenty though.

Oh ok that solves my question

Corky's first IC for the FM turbo stuff was way too small. Sometimes he should TRY stuff instead of math/engineering it to death. The early FMII ICs lagged way behind the AVO turbo ICs with the same size turbo.

Frank

What I posted was at least his thoughts on tube/fin vs. bar/plate which still hold true.

His new edition will have a completely revised section on intercooling.

Sidenote: he just asked for my mailing address yesterday, I wonder what he wants to send me. :confused:

who knows.


i also understand that the tube-fin style has better airflow to the radiator since the rounded tubes are a bit more aerodynamic than the bar/plate tubes.

bar and plate is also more robust. the extrusions are very sturdy. especially when welded up.

You wont give up any power. As long as it is big enough, either design is fine. Bar plate gives less pressure drop but isnt as efficient. Tube-fin doesnt flow as much, but what it does flow gets cooled a lot better.

Bar plate is slightly sturdier but also lots more expensive, since most bar-plates are custom aftermarket jobs and most of the tube fin intercoolers are OEM ones that have been converted to project use. I'm using a tube-fin mk3 supra intercooler that has served me very well for years now.

That reminds me of another thing. Take things other car owners say with a grain of salt. An intercooler that "sucks" might have been fitted to a much larger engine or have very restrictive stock tubing around it. The MK3 intercooler is supposedly a turd, but it is a huge (for a miata) unit with nice end tanks (I relocated mine), perfectly sized for a T3/T04 sized turbo (2" inlet/outlet) and you can easily make much more direct pipes than the MK3 supra comes with stock (looks like spaghetti under the hood).

Also, beware of small bar-plate jobs that have crappy end-tanks and are sized for 180 whp D series honda turbos. Lol ebay.

This is back from when I painted it. Yeah, engine enamel > powdercoat.
http://i14.tinypic.com/4csg4es.jpg

It would be worth the time to go in with a plastic stylus and straighten the dented fins.

bar and plate are also nice because they're totally modular. you can make them any size you want just by stacking more layers. kinda like a scooby doo/shaggy sandwich

http://ghoul-school.freeonlinegames.com/images/1867.jpg

good analogy. Did you do good on your SATs?

good in math. but rather than study for the verbal, i watched cartoons.

ah, now I see how it all comes together.

I took that picture 3+ years ago. I regularly go back and straighten the fins and pick the bugs out.

What kind of air temp rise are you guys seeing from boost onset to redline/shift (list numbers)? and what intercooler? size?

I don't think tube/fin is the cheap intercooler anymore- not with the chinese making the bar/plate.

none - 2 and 3rd gear pull 78 rising to 80 at top of second, drops and holds to 78 through third.
this is consistent as well, all of my datalogs have shown no more than a 6-7 degree increase over several pulls.

C or F?

I typically see 10C (give or take) above ambient just driving around. It goes up another 10C or so in boost but drops back down quickly. I havent datalogged in a long long time. Typically in low 90s ambient I will be around 40C or so just puttering around. In boost I can get up to mid-high 40s C.

Basically the car is fast below 90F weather, sluggish above. Below 40F, the car is very fast but I have to redo the EBC settings to avoid overboosting.

F
Yeah, below 40 is a huge difference on a turbo car. Course its only been like that a few weeks all winter...