SPAL FANS and 2 ROW DEWITT'S TECH Notes

[GOLDCYLON]

While this thread started as a WTB thread it turned into a tech note thread. MY install comments and impressions start at #29. GC

[FU]

Check with Pete, he may have the DeWitt's Rad.

[GOLDCYLON]

Thanks Frank I pmed Pete

[Polo-1]

used the DeWitts in the 94 AB car Matt has. GM fans. Nice fit.

[RHanselman]

Any out there for sale ?:cheers:

Any comments from the membership on these ?:cheers:

Daryl,

What are spal fans? I have a source for new fans if you're interested.

Also, just wondering why Dewitt? I've not been keeping up with the trends these days.

As I remember there was Dewitt, Ron Davis, Fluidyne and stock.

Cheers,

[PhillipsLT5]

Ron Davis is in town, maybe they can make you what you want

[GOLDCYLON]

Daryl,

What are spal fans? I have a source for new fans if you're interested.

Also, just wondering why Dewitt? I've not been keeping up with the trends these days.

As I remember there was Dewitt, Ron Davis, Fluidyne and stock.

Cheers,


Bigger fans to cool the car down that mount like factory. Since I punched my car out its having problems in traffic at 118 staying cool.

[GOLDCYLON]

Ron Davis is in town, maybe they can make you what you want


I heard their fins are a little too close and overheating can be an issue ?

[efnfast]

Bigger fans to cool the car down that mount like factory. Since I punched my car out its having problems in traffic at 118 staying cool.

Why are you doing 118 in traffic?[-X

[GOLDCYLON]

Why are you doing 118 in traffic?[-X

What am I doing? melting :-x

[RHanselman]

Just wondering, how are your oil temps?

[GOLDCYLON]

Just wondering, how are your oil temps?

Never beyond mid point. Temps really climb with Ac on. Bought new 2 row with spal fans.

[PhillipsLT5]

http://www.summitracing.com/search/brand/spal-automotive-usa?autoview=ProductName

http://www.summitracing.com/search/brand/dewitts-radiator/product-line/dewitts-radiator-direct-fit-radiators?autoview=SKU

[RHanselman]

I have the same problem with my Turbo LT1 car. The A/C drives the temps up pretty darn good when I was in Vegas... I'm going to pull and inspect the Rad and was thinking of upgrading the fans. Where did you source the Spal Fans?

[RHanselman]

http://www.summitracing.com/search/brand/spal-automotive-usa?autoview=ProductName

http://www.summitracing.com/search/brand/dewitts-radiator/product-line/dewitts-radiator-direct-fit-radiators?autoview=SKU

You're quicker than I was... :)

[tf95ZR1]

My OEM radiator plastic tank separated from the core, so I used that as an excuse to get a Ron Davis radiator.
(I consider the RD rad in the same category as a DeWitt's.) To cool better, it is thicker than stock so I had to trim
the fan shroud. BFD. Car runs cooler in general.
Assuming the basics: radiator is clean and not blocked, coolant is correct (water wetter?), thermostat works, etc.
there are some other options to run cooler:
-Have you tried cooler spark plugs? Consider them your summer plugs.
-A high rise hood. Not only more room for air flow, but more air can suck in from in front of the windshield.
Not to mention how COOL it looks!
-Down shift. Counter intuitive, but it works. You can thank the Z's cooling system design.
Obviously in stop and go traffic this is useless.
-manual fan switches

I've never understood how a 160deg thermostat will make the system run cooler than a 180deg stat.
Yes, it will open sooner, but eventually the system temperature will rise to it's open thermostat "equilibrium" temperature
(greater than 160) regardless, right?

[GOLDCYLON]

I have the same problem with my Turbo LT1 car. The A/C drives the temps up pretty darn good when I was in Vegas... I'm going to pull and inspect the Rad and was thinking of upgrading the fans. Where did you source the Spal Fans?

Dewitts sells then as well as a direct fit... Im $900 lighter although

http://www.dewitts.com/collections/corvette-aluminum-radiators/products/1990-1996-aluminum-radiator

[GOLDCYLON]

-A high rise hood. Not only more room for air flow, but more air can suck in from in front of the windshield.
Not to mention how COOL it looks!

I agree
-Down shift. Counter intuitive, but it works. You can thank the Z's cooling system design. Obviously in stop and go traffic this is useless. -manual fan switches

Actually I got relief when I up shifted esp to 6th gear at freeway speeds in 5th the temp would slowly climb

I've never understood how a 160deg thermostat will make the system run cooler than a 180deg stat. Yes, it will open sooner, but eventually the system temperature will rise to it's open thermostat "equilibrium" temperature (greater than 160) regardless, right?

Your right as I understand it a specific temp of a thermostat allows the passage of rad water beyond a specific heat range. Its actually better to keep the water in the radiator as long as possible as thats air cooled before letting it go into the rest of the motor. So a 160 allows the water to start flowing sooner however all the cooling occurs in the radiator. Hopefully the increase in capacity and bigger fans will resolve my issue. D

[GOLDCYLON]

Holly Crap Dewitt's finally shipped the radiator a week after I ordered wow. Very slow IMHO.

[tf95ZR1]

Hey be careful, GC.
Aren't they a supporting vendor here?
Don't want to be banned.....

Oh wait, you're a mod!

[GOLDCYLON]

Hey be careful, GC.
Aren't they a supporting vendor here?
Don't want to be banned.....

Oh wait, you're a mod!


No Idea reguardless they should have told me when I paid them it would be a week before it went out the door.

[RHanselman]

Take a look at this guy's custom Dewitt unit... Pretty slick...

http://forums.corvetteforum.com/c4-forced-induction-nitrous/3165200-supercharging-an-lt1-corvette.html

[GOLDCYLON]

Take a look at this guy's custom Dewitt unit... Pretty slick...

http://forums.corvetteforum.com/c4-forced-induction-nitrous/3165200-supercharging-an-lt1-corvette.html


Thats a little more than I was looking for Ron. However, for that application it sure made his clearnce issues go away. IM sure that was not cheap. GC

[RHanselman]

Thats a little more than I was looking for Ron. However, for that application it sure made his clearnce issues go away. IM sure that was not cheap. GC

Yep I figured but it is cool no pun untended... Not cheap is probably right...

Did you get a chance to install? I'm interested in your results.

Cheers,

[GOLDCYLON]

Yep installed resolving an AC issue at the moment although

[vilant]

Was curious, if you the saw the post (can't remember where or who did it) where they removed sections of the front wheels wells with screen to help bring in air flow to the engine compartment. Have you done this mod? It may help keep things cooler in those hot desert climates your driving in.

[A26B]

I have the Ron Davis in my ZR-1

The Ron Davis is a racing radiator that has 5 cores as compared to the stock 2 core. As a "racing radiator" it performs best at racing speeds where air velocity is high. Being thicker, actually makes it more resistant to air flow than the 2 core radiator.

A simple but effective modification that yields significant results, is to drill 3 or 4 holes in the thermostat flange, just inside of the seal contact area. This modification reduces back-pressure for coolant passing through the radiator & thermostat and therefore allows more flow coolant through the radiator, instead of the bypass. Bypassed coolant means hotter temps.

I strongly suggest you perform the t-stat modification before spending a lot of time & money on expensive radiators and fans.

As a side note, the only way to insure the stock radiator is as effective as it can be.... is to remove it and insure all the gravel & debris is removed and the vanes are reasonably straight.

[GOLDCYLON]

Well Everthing is in I will give you my impressions after the drive home. AC issue was a pressure switch leaking next to the suitcase.

Dewits drilled out the spal fans brackets backwards which was a PITA. Had to reverse the back and tap and die them out the other side.

GC

[GOLDCYLON]

Well went with the all Aluminum 2 row and the spal fans. Solved my cooling problem so far in Phoenix. I also installed the R Woods 160 degree thermostat I have had for several years in my parts bin.

Two Mondays ago Freeway reading on I-17 for the outside temp on the HVAC controls swung from 122-119 on the drive home on that day the raditaor rose to almost 75%-80% of temp band prob 225. AC was on full.

The Fans roar with a pitch that you normally hear on the newer cars (Plenty of air movement). You will gain a little more room in the front of the motor as the back side of the OEM shroud with the OEM fans are no longer used. The receiver drier needs to shift a little towards the passenger side but the same bracket can be retained.

Notes on this project: There is a 2 week flash to bang time for delivery once you pay. I learned this the hard way, Also as mentioned above the SPAL Fan brackets mounting screwholes were made upside down from the factory so we had to retap and turn the bracket the right way to get it to work. Kind of a PITA

Plan on spending $900 in parts just to do this project. There are no discounts. I'm happy with the results however beware of the timelines and problem issues.

I also do have one additional comment. If you are running a bone stock LT5 the stock factory radiator if its clean and free of debris, silt and sand will work well. I did not have cooling problems until after I stroked my motor, installed bigger inake cams etc. This stands to reason more HP requires better cooling options than stock. The same logic follows for beefing up braking and the rear end, transmission etc to handle the extra HP and Torque. GC

[RHanselman]

Daryl,

Just wondering, what kind of HP/TQ you getting from that 380?

[GOLDCYLON]

May know soon as Dom and I have here close to a final tune.

[Billy Mild]

I have the Ron Davis in my ZR-1

The Ron Davis is a racing radiator that has 5 cores as compared to the stock 2 core. As a "racing radiator" it performs best at racing speeds where air velocity is high. Being thicker, actually makes it more resistant to air flow than the 2 core radiator.

A simple but effective modification that yields significant results, is to drill 3 or 4 holes in the thermostat flange, just inside of the seal contact area. This modification reduces back-pressure for coolant passing through the radiator & thermostat and therefore allows more flow coolant through the radiator, instead of the bypass. Bypassed coolant means hotter temps.

I strongly suggest you perform the t-stat modification before spending a lot of time & money on expensive radiators and fans.

As a side note, the only way to insure the stock radiator is as effective as it can be.... is to remove it and insure all the gravel & debris is removed and the vanes are reasonably straight.

What is this Thermostat mod that can be done?

Thanks,

Jeff

[secondchance]

What is this Thermostat mod that can be done?

Thanks,

Jeff

I think the thermostat mod mentioned is drilling 1/8" hole/holes on the thermostat flange. I drilled three 1/8" holes at first. This worked fine during the summer months. However, once it got cold coolant temp wouldn't go above 150. So, I switched to another thermostat with just one 1/8" hole. This reduced interstate cruising coolant temp in summer from 208 to 213 (depending on 5th or 6th gear) down to 196 plus/minus and during the winter around 180 to 185.