rlets

Tune is an interesting thought. Have you looked at your plugs? Do you monitor fuel pressure? If you're running on the lean side, temps will skyrocket.

Rich

docwyte

I've got a wide band O2 A/F meter in the car, at WOT it usually reads around 12.6:1, which is where a NA tune should be. I do have to get the tune cleaned up a little bit though, so I'll have them look into it...

rlets

Yeah, 12.6 is pretty good. You could phatten it up a bit to make it run cooler, at the expense of power. Another option if some of this other stuff doesn't help. 250+ on both water and oil is scary hot.

Rich

docwyte

I'm not worried about the oil temps at all. 250F is nothing unsual, particularly out here. If I'm seeing 250F, my friend in his C5 Z06 is seeing 290-300F. It's just my coolant temps that I'm not happy with.

It could be I'm running too much timing. I need to find a FAST 90 intake manifold, put it on along with the 90mm throttle body and 85mm SLP MAF and get the car retuned.

TonyG

The FAST90 isn't worth it over the LS6 setup. You need to go to FAST 102 to make it worth it. Assuming you have a LS6 intake, dual 2.5" exhaust/headers, your cam choice alone can get you to 400RWHP (I got 417RWHP with a cam too big for the street).

At 417RWHP with a big cam, it took me a CNC heads, flycut pistons, flycut heads, FAST 102, 92mmTB, 85mm MAF, to pick up the next 30RWHP.

Then it took no MAF, 1.8 rockers, under drive pulley to pickup the next 12RWHP.

There's no more to get.

My point being that your cam choice will be the biggest power gain.

As far as cooling goes... There's n point in cutting up the front end of the car as it's not the problem. You have to have the "box" in front of the radiator sealed, and the radiator needs to be fairly new. Hood venting will help. On the race track the stock water pump can be a problem because it will cavitate at high rpm. Also, the system needs to be properly bled.

Ultimately I had to go to a larger radiator, but that was because of 1) making a lot of power, and 2) racing on hot summer days.

TonyG

disasterman

I have a RH radiator for sale!!!!!!!!!

docwyte

What are you using as an adapter to fit the 92mm throttle body? Should I just go with a speed density tune to begin with and delete the MAF entirely? So far I've kept the MAF because of the large altitude changes I can hit within an hours drive here.

Right now my motor has an intake restriction, I'm pulling vacuum up top. I have plenty of cam, but it's not making the power that it could because my intake is choking it. What did you end up using for a fuel rail and injectors with the 102?

What radiator are you using? I have a new OEM turbo radiator right now. What water pump are you using and what procedure did you use to bleed the system?

docwyte

disasterman, PM sent

odurandina

how 'bout running an even bigger oil cooler?

TonyG

I made 417RWHP with a LS6 intake and 78mm TB with a stock LS1 75mm MAF with the current Futral F-16 cam and 389RWHP with MTI Stealth 2 grind (apples to apples, no other changes except a cam swap).

How much power are you making now?

I have a RH radiator in there now. And it seems fine. I also have an aftermarket water pump due to the fact that the stock LS1 water pumps (according to my engine builder) cavitate at high rpm.

I have custom fuel rails on each side with the FAST 102 as well as larger injectors (the stock injectors were fine at 417RWHP).

Also... you won't be able to fit the FAST 102 with a stock hood without sectioning out a section of the center brace. And you also will probably have to some how raise up your strut brace (I had to raise mine up 1/4" on each side via custom spacers.

When I bleed the system, I fill it, leave the radiator cap off, then undo the steam vent cross over hose (the hose that's connected to the T in the water pipe between the heads).

I keep adding water until there's a steady stream of water coming out of there filling up the radiator tank along the way.

Once you have steady water coming out... then run the car. Get it hot and loosen that hose again pull it. You will probably see it spit water and air. Keep doing that until it's solid water. Once it's solid water... you have the air out.



TonyG

docwyte

I'm making 375rwhp now. Another guy with basically the same setup as me (different tuner though) is making the same power too. I can't see picking up another 40rwhp without doing the FAST 102.

How much taller is the FAST102? I probably have 3/8" of free space between my LS6 intake and my strut brace now...

First thing is to rebleed the system and see if any air comes out. I didn't burp the steam vent when I put in my latest radiator last Fall...

My oil temps are under control, so I don't think a larger oil cooler would work.

Tony, does the RH radiator fit with the OEM 951 cooling fans?

acorad

If the RH rad is the same width as the OEM rad, and I'm pretty sure it is, then the side-by-side twin 951 cooling fans should fit, assuming you mod the RH rad so the OEM fans can attach to it. By my calculations the twin fans will pull air from more square inches than the single RH fan does. Not that the cooling fans are your problem, as you are getting too hot at speed, not at idle.

Did your engine ever get too hot around town in traffic with the A/C on?

docwyte

Nope, only gets hot on the track, I see 200F on the street with the AC on.

TonyG

You're wasting your money on the intake/throttle over the LS6 setup until you're making considerably more power.

A bigger cam will get you up to and over 400-415RWHP depending on the grind and how much of a rough idle you're willing to put up with whereas the 102MM FAST/larger TB will maybe get you 10RWHP ish with the "mild" cam you have now. Where the FAST shines is up top, but you can't take advantage of that because of the smaller cam.

The cost of the intake, throttle body, fuel rails, fittings, etc... will cost you close to $2000. For how much power? 10-12RWHP?

If you have $2k to throw at the car, pull the heads and have them CNC ported. RPM CNC ported mine and it's like $600 to have them ported. That will get you 2x the power of the FAST intake for 1/2 the cost.

Take the rest of the savings and put in a bigger cam and TI springs/retainers.


As far as the radiators go... my RH radiator is taller than the stock radiator by like 1" and appears to be thicker too.

And on the track... you don't even need fans. Most race cars on the track don't even have fans. None of the water cooled 996/997 race cars even have fans. For a street car... the RH fan is fine. If you want more air to pull through, then it would really only benefit the A/C condenser. I don't think the stock fans will work with the RH radiator because you have no mounting tabs (easily fixed), but I seem to recall the RH radiator being thicker. I don't think the stock fans will clear the water pump pulley.

Lastly, where are you taking your temps from? Using what sender/gauge?

TonyG

disasterman

Photos of my cooling set up and the spare RH radiator that I have.