Podium

I need a new radiator and have been looking at RSD and dewiit. I like the cutdown and plan to use a custom 4 inch intake with my blower. Are there any cooling issues with these? My car is black and on 90 degree days it gets rather hot. RSD is going tio have a black friday so no is the time to pick one up. Any experiences?

EnginerdVT

I think most with real world experience would tell you to shy away from cutdown radiators unless you absolutely need to and, in that event, try to separate the trans oil cooler (TOC) and engine oil cooler (EOC) into their own and not have them both also flow through the radiator. After supercharging myself, I'd had mostly great luck with the Griffin cutdown radiator (has both EOC and TOC), but on really hot days when the car heat soaks (no vented hood), I get to about 215-220 and then it slow creeps up to about 230+ if I'm moving REALLY slow in traffic. That being said, there are things that affect that like your tune (lower timing causes heat so that is important for idle and cruise!). Things like upgraded cooling fans (D3P or similar) and different fluid combinations like all or mostly distilled water instead of common 50/50 mixes can help along with additives to help boiling point (especially seeing 220 degrees or more), althought the system is slightly pressurized to prevent a 212 boiling point.

Just figured I'd vomit some information... I'm sure Nick and others will chime in to correct me and add with their wealth of info, but I'd suggest staying full size core if you can and lowering things down enough to jam the 4" pipe in there, or going cutdown but trying NOT to run the EOC and TOC through the cutdown radiator to save on capacity for HOT days...

Shikaitsu

The Mishimoto radiator for the C6 is notched out of the box and clears a 4" intake into the throttle body. It's also the same height as stock and twice the core thickness so it will improve cooling.

EuroRod

FWIW............... I have a DeWitts history. First one was the full size with EOC. It worked OK for a stock engine with a PS1. When I upgraded my engine, I replaced it the shorty model and installed a separate EOC. I replaced this set up within 300 miles because it simply did not cool sufficiently. My ProCharged 6.8ltr LS2 experienced coolant temps in the 240+ range in summer heat. I am currently running their full size radiator, and, with the separate EOC, it works fine. DeWitts does make a superior product. Just need to select the correct one for the job.

Unreal

No good reason to run cut down. Modify mount if you really need a pretty intake tube. You can make 1000+ with ease with either stock inlet and just take it off for races. Filter is typically restiction before the tube. Yes cooling takes a hit with smakker radiator. If it is a race car that doesnt have ac, doesnt drive when hot, etc then do whatever.

Podium

Unreal

Ti wont stress the inlet. Run a full size.

Podium

The 30 to 60 horsepower is worth it to me. I also intend on switch to a YSI in a couple years so Im also planning ahead.

Unreal

Won't be near to that hp and as I said, you can run a 4" without curdown and just pop inlet off for races.

Podium

Im running a A&A kit(C5). How can I run a 4inch intake with a full size radiator? I already have the spacers in the radiator support from the kit. I dont see how that will work.

I cant belive that the A&A dongle isnt restrictive, it gets super thin over the radiator. Wish I would have thought to take off the filter, then the dongle when I was dynoing it.

realcanuk

You asked if the cut down hurts cooling and a few guys with experience have told you it does.
Also been said that guys have made 1000 with the dongle, and you won't be near that.
Why ask if you don't believe the answers. Try a cut down rad and let us know how that goes.

Podium

Because unlike most people on the internet, I do my research and dont go off of what one person says. Not saying unreal is right or wrong, just want more input and feedback. Just because someone has made a certain amount of power doesnt mean they know what they are talking about. Thats not directed at anyone, I just personally know a few locals that have made 800-1300 and not the smartest.

Unreal

Multiple people told you the same thing. Yes it runs hotter and doesn't cool .early enough for most street cars. You are just waiting for one person to say it runs fine to justify doing what you want.

You can modify the cradle to lower the mounts. Either way filter is far more restrictive and if you want to make 1100+ need to take filter off. Just pop the whole inlet off when making 1050 isn't enough and run a screen or vstack. Enjoy the better cooling. There is no decent reason to run cut dowm radiator.

Podium

No, thats not it at all. If someone says to run it and its cools great, I will question them as much as I am you.
Thank you for saying I can mod the craddle. I will research that. Trust me, Id much rather run a full size than the cut down.

Just want to maximize the set up.

realcanuk

Some pics in this thread on how I did it....

https://www.corvetteforum.com/forums...r-support.html

playtoy

Ok. I'll be the exception to the rule. I have been running the cut-down radiator for about 8 years now. I have only had cooling issues once (gridlocked traffic in the Houston summer). My car is a sleeved LS2 block, making just under 1100 at the wheels with a cut-down Dewitts (no coolers in the radiator) and electric water pump with a 180* thermostat, dual spal fans running on the factory controller. I am switching to an LSX block this month so i might experience some cooling issues with the iron block but we will have to see.

realcanuk

I bet the electric pump helps quite a bit in traffic. If I just hold my engine speed at around 12-1400 rpm in traffic the increase flow quickly drops the temp by around 5 degrees.

Unreal

I also have cutdown and got it to cool after spending $3k+ in other cooling mods. Didnt know about lowering cradle 6+ years ago or the fact the 4" tube basically does nothing, it is all in the filter. Like i said, no good reason to run cut down these days. Also limits fan selection. Yes it hurts cooling, enough to overheat depends on use, combo and location. If i lived up north, hell i would run a half size honda radiator.

Podium

Unreal

Which spal? There are good and bad ones. Cheap ones worst than stock. Have to spend $600+ for any decent ones. Prospeed dual setup is the way to go.