I'm kinda bored and I was thinking of trying this other intercooler I have here. its uses three spearco 9wx6hx3.5d cores, vertical flow with inlet and outlet on opposite sides. Supposedly good for 1200hp.

Compared to what I have on the car, the old OBX horizontal flow. 24wx12hx4d with the inlet and outlet lined up.

my thoughts on this..

The OBX is nearly double the overall core size and thicker, it only has 16 tubes, the fins in between are not very dense and I dont think it removes heat very well. BUT, it most likely makes a great 'heat sink' since its big and heavy and takes a while to heat up just from the sheer size of it. OTOH once it gets hot it stays hot as well.

The other IC has 51 tubes acress it the fins are very fine and dense, obviously more quality and more expensive to make. Its probably much more efficient as well. Since it weighs half as much as the OBX it probably isnt a good 'heat sink' but most likely it will tranfer the heat out better when the car is moving.

I'm a little leary of only having 6" of core height, even though I'm sure it will have less pressure drop then the OBX since there is a lot more tube area and its shorter. But there is also the 90 degree turn at the inlet/outlet as opposed to the OBX which is a straight shot. Granted its easiest just to swap them and see but honestly its way to hot for me to go to the track and I figured I'd see what people's opinions are before I go through the trouble of reworking the pipes

Any opinions?

 

Interesting topic, and it would be great to see some actual results.

The trend here in UK/Euro seems to be for side-side style, with long tubes.

The trend for most IC's Ive seen in the US, seems to be for shorter tubes, up/down, but much more of them.

I guess best thing to do would be to measure intake temps after the IC, and boost pressure before/after.

If the longer tube style is posing a restriction, then it may be worth trying the shorter tube version.

If it isnt posing a restriction, then will switching offer any cooling benefits that would make it worth while ?

 

Thats what I'm wondering, I highly doubt the OBX is very restrictive at all from the boost numbers I'm seeing 8K under max redline. But pushing the air though 16 long tubes vs 51 short ones would seem to favor the 51 short tubes I would think. But theres the 90 degree turn in and out that will cost some flow..

This car is very sensitve to IATs, even knocking it down 5 degrees would help a little not to mention taking over 10lbs off the front of the car. But seeing the is primarily a drag car the huge mass of the OBX may well make up for any ineffciency at the dragstrip. Even starting off at 100 degree IAT on a 90 degree F day the highest I have seen is 145 degrees at the end of the quarter and thats not really bad for the amount of air the blower is moving.

 

Be cool to see the results, I would only do it if I could find a way to leave the pipes unmolested until solid results are in hand.

I'm working up a lil experiment too in regards to intercooler cooling. But laying on the ground/under the car hurts a tad due to the mid week operation....guess it'll have to wait till next week, can't even change my own oil right now


I'm saying 10-15 deg difference between the two.....

J

 

I would just have to make an 'S' shaped pipe for the RH side and it would be easily swappable. I could even run down to a local track without the nose on it and swap them at the track.

I dont think there will be that huge of an IAT difference but you never know..

 

id keep the old pipes just incase the new one doesnt perform as well.
i think only real world testing will show for sure.

 

I agree, even though my garage and computer room is air conditioned the dragstrip isnt - so I'll discuss it a little first since its a lot easier lol.

 

looking at the size of the core, ~10 deg is a safer bet, if I was betting.
Too bad they aren't even size wise and construction wise, now that'd be a good sidexside test.

J

 

If they were the same size cores it would be a no brainer, there are 17 tubes per 9" of core on the spearcos and the fins are very fine and very dense plus split into a few different sections. There is no doubt which would be able to transfer the heat into the air better. But I think just the sheer mass of the OBX may make it a winner at the dragstrip or short highway blasts..

Then again I could just also do the T88 with the spearco IC and see which whole setup is better lol.

 

Just perfect for what we use it for. During extended highway use I see it only register 10 deg higher than ambient and cools rather well after off the throttle. Now if I stack a few WOT blasts back to back it starts to get heat soaked pretty bad and recovery time is real bad. Hence my experiement thats in the works.

Nah been there the procharger hands down as the better of the two
Either way, you'll make it fly

 

I have all the stuff for the turbo, if I didnt have to relocate the alternator and change my fuel regulator around I would do it this week. After messing with the fuel system the last few days I dont feel like screwing with it. I also did a Synergy 2 step/trans brake control and electric water pump as well.

Wired the stock fan switch on the heater control to control the rad fan, the EWP on the mode switch on the heater control. I used an old electronic fan controller I had laying around and used an external pot hooked to the temp control in the center so when I get done with a pass I can set the fan and water pump to shut off at whatever temp I want from 135 to 180 degrees. Plus have full manual control of either.

Also wired the 2 step 'arm' button and LED to the stock radio power btton and the theft lock LED on the radio flashes when its armed.

I have too much time on my hands sometimes lol but I hate a row of toggle switches on the dash.

 

WERD the less switches the better, too much clutter sucks. I hate wiring stuff up for that reason. When it comes time to race one switch will take a dump when you need it most

So you went with the synergy two step? How was the hook up, and if you don't mind how much was the cost?

If you need a relocation bracket let me know, i'll take mine off and have my buddy plasma cam one for you.

I just have the PCM controlling the fans after a pass, shut the car down and they stay on for 2-4 minutes depending on which tune I have in there. I'll utilize this feature when doing the IC cooling trick as well.
J

 

Cut me up one of those alt brackets, the one you had was pretty nice if I remember. Trade you a z06 cam for it, I swear I'll get it shipped out next week

The synergy 2 step was an easy hookup, after talking to the guy who designed it he went and made one of the nitrous control sections control the trans brake solenoid to keep the current across the switch low so the button lasts forever and eliminate any relays - worked out real nice. Easy enough to wire up but you have to solder 8 wires to the pcm wiring, not really a big deal though and I hate doing wiring It was 260.00 or something like that.

The fan controller I use alternates the water pump and cooling fans. The water pump runs for 30 seconds, shuts off, then the fan runs for one minute, shuts off and keeps cycling like that until it hits the temp thats dialed in. Easier on the battery and it can go from 210 degrees to 150 in under 10 minutes on a 90 degree day - works very well..

I was going to try to come up with a way to cool the intercooler off better or even do an A2W with ice, but I decided it was a lot easier (and cheaper) just to wait a month or two until it cools off around here a little..

 

Spent a bunch of time on the phone with Gerhard (Corky Bells partner/engineer in Bell). According to his equations you get less than 30% thermal efficiency in width of core vs height of core in a vertical flow IC. Basically, if you lose 3 inches of flow length, you would need 10 inches of flow width to approach (not equal) thermal eff.

Quick version is your existing IC will have more pressure drop but be much better thermally than the Spearco unit. Your talking 24inches of thermal flow vs 6....core is a little better designed(Spearco...looks exactly like my Bell core)...but it's not going to make up for 24 inches of thermal flow OBX unit.

Be interesting to tap the OBX before and after the IC to see max pressure drop at 16psi....I bet it's at least 2psi.

Just rambings from a clockmaker

 

still thinking aobut the turbo?
i got an alternator bracket ready to go if you want one too.

 

more fins per inch generally means more cooling capacity. since you have time on your hands and since you're bored why not try the other intercooler out and see what happens?

where do you guys set your fans to come on? I have a 160 T stat but my engine temp according to my stock gauge is still near the middle mark, i guess around 200 or so. I want my motor to stay a little cooler especially with how hot it is now here, 94 degrees with minimum 60 percent humidity.

 

I have everything here to do it, would like to get in the 8s with the procharger before I take it apart for a while but that will take some much better weather. Dont feel like investing in an F1 knowing I'm going to swap to a turdblow soon

I'll keep you in mind for the bracket if I end up need ing one though.


I dont disagree but I would think the better core design may bring the two a closer together cooling-wise. The OBX probbaly isnt the most efficient core out there.. Its possible these are Bell cores, I was just told Spearco and since no receipt or nothing is marked who knows. But its pretty easy to spot the difference between the OBX and this one.

I woudlnt doubt 2 psi or so drop with the OBX @ 16psi..

Its no problem to swap them, take about 2 hours. Problem is I'm not going to the track when its 90 degrees out and 80% humidity to test it. Its not just hot in Florida, its hot here too PLUS 2000' elevation to start with lol.

My fan comes on at 175 or so. Ten degrees above the thermostat opening point is where most people set them. When its that hot I doubt it can sustain 170-180 degrees on the stock cooling system though..

 

Cool will do on the bracket kev, since I have some time on my hands i'll see if I can knock it out this week.

Don't have an ungodly bracket staring you down when you pop the hood and the fuel rails are clear of the alternator as well. Might have to clock the breather on the pass side valvecover some but it's a small price to pay.

J

 

Yea, if I remember yours looked pretty nice, really doesnt matter that much to me how it looks though as long as the belt stays on @ 7000rpm

I may pull the nose/headers off tomorrow and see if I can fit at least a 3.5" DP between the mount and block. I have an older PA k-member that uses the giant stock stands for the mounts. So I dont know how much room is there but I know a 4" wont go.

 

4 inch oval pipe maybe, or even 5inch oval from dr gas if need be?

Oh yeah the belt will stay on past 7100 even with the stock tensioner...but I run the katech now because I found a good deal on it.

J