LS1GTO Forums banner

1 - 18 of 18 Posts

·
Registered
Joined
·
42 Posts
Discussion Starter #1
The really big issue for these cars is inlet air temp.Have been intrigued by the mods made by the Predator and had a lengthy conversation with Diablo today.Here is the deal.They do not modify the speed fan cutoff so the fans cut out either at 30mph or a calculation made by the PCM based upon ac settings and other parameters.This is good because the fans Kicking in early lower both the ECT and IAT Thus,although they are on most of the time at idle they do go off at speed, as the PCM over rides temp control SO I would suggest sticking with the Predator on&off settings .

Now here is the deal on temps versus ignition advance curve.If you feel the car being sluggish or sorta flat with high outside temps, read on. Per Diablo, they do not alter the retard formula controlled by the PCM based uppon temps.At 86 degrees F as measured by the IAT sensor ,total advance is retarded 1 degree,at 95 degrees 3 degree advance reduction,113 degrees,4 degree advance reduction,and 1 degree retard for every 9 degree increase in IAT over that up to a total retard of 11 degrees

Thats a potential loss of almost one third of total advance.Remember these are factory settings and are not altered by Predator .Predator does alter total advance and the curve by not retard curve so as to prevent the KR from kicking on.

Today it was 94 degrees F. AT idle my IAT was 141 degrees.Driving around town at 30 or 40 mph it never dropped lower than 134 degrees.Thus if I hit the go pedal at any of these times my advance was 6 or 7 degrees retarded making the car feel a little down on power.On the open road I drove 12 miles at 60 to 70 MPH and the IAT never dropped lower than 104 degrees or 10 degrees higher than outside temp.Retard still of 4 degrees.......this is a power killer ,Im running stock intake and do not feel any available CAI add on will do any better without external ducting to get away from heat soak under the hood..folks heat is the enemy and the ls1,ls6 are fussy when it comes to heat
 

·
Knight Errant
Joined
·
1,800 Posts
Here's what I am thinking, FWIW

I'm beginning to think we need to fight this two ways. Firstly we need as close as we can get to ambient IAT. My Predator monitoring shows I am getting closer in the direction I am going, using the stock Airbox with mods and the Speed Tube. I think I need to look further at insulating or heat shielding all that black plastic. I think the second line of approach is to get as much heated air out of the engine compartment as fast as we can. The Predator running the fans at all times under 30 MPH helps (where the computer overide turns them off). Florit's car should be doing a better job of this with the louvered hood. Florit may be able to tell us if this is the case. We others may have to get 'creative' to accomplish this.
On the S-10, I removed the flaps that cover the upper A-frame cutouts in the wheel well panels, removed the rear hood seal to the firewall, and spacered the rear of the hood to make a 1 inch gap back there tapered center to the sides. What resulted was hot air coming out while sitting still, evidenced by the cowl drawn higher than ambient air temp of the 'Astral Ventilation' into the cab, and apparently cooler air going into the engine compartment (while driving over 40 MPH) off the higher pressure area in front of the windshield. (Ventilation temp in the cab returned to normal while driving). So...If cooler air is going in there and at the grille sides around the unsealed electric fan cooled radiator while driving, hot air has to be leaving somewhere, I think under the truck and out the wheelwells. The hood trick 'might' be partly possible on the Goat. There is a seal there to remove, and maybe by shimming the hinges....hmmmm. The fenderwell opening trick will not work, there aren't any. I'm also thinking one way to lower the IAT for the strip might be a big chunk of ice under the panel filter when making runs. :sneaky:
 

·
Registered
Joined
·
155 Posts
Removing the seal at the Cowl was one of the first things we use to do with the Turbo Buicks to let the hot air excape.
 

·
Knight Errant
Joined
·
1,800 Posts
Hardware said:
Removing the seal at the Cowl was one of the first things we use to do with the Turbo Buicks to let the hot air excape.
How much did it help? There was a LOT of heat under there in those cars!
 

·
Resident 10-second Priest
Joined
·
8,959 Posts
FWIW, I monitored my IAT with HP Tuners during my recent trip through the desert of West Texas. Ambient was maybe 95, but easily 100 on the road. Never saw more than 100 on the IAT. Here's my setup:





Padre
 

·
Registered
Joined
·
2,691 Posts
Old Goat said:
I'm beginning to think we need to fight this two ways. Firstly we need as close as we can get to ambient IAT. My Predator monitoring shows I am getting closer in the direction I am going, using the stock Airbox with mods and the Speed Tube. I think I need to look further at insulating or heat shielding all that black plastic. I think the second line of approach is to get as much heated air out of the engine compartment as fast as we can. The Predator running the fans at all times under 30 MPH helps (where the computer overide turns them off). Florit's car should be doing a better job of this with the louvered hood. Florit may be able to tell us if this is the case. We others may have to get 'creative' to accomplish this.
On the S-10, I removed the flaps that cover the upper A-frame cutouts in the wheel well panels, removed the rear hood seal to the firewall, and spacered the rear of the hood to make a 1 inch gap back there tapered center to the sides. What resulted was hot air coming out while sitting still, evidenced by the cowl drawn higher than ambient air temp of the 'Astral Ventilation' into the cab, and apparently cooler air going into the engine compartment (while driving over 40 MPH) off the higher pressure area in front of the windshield. (Ventilation temp in the cab returned to normal while driving). So...If cooler air is going in there and at the grille sides around the unsealed electric fan cooled radiator while driving, hot air has to be leaving somewhere, I think under the truck and out the wheelwells. The hood trick 'might' be partly possible on the Goat. There is a seal there to remove, and maybe by shimming the hinges....hmmmm. The fenderwell opening trick will not work, there aren't any. I'm also thinking one way to lower the IAT for the strip might be a big chunk of ice under the panel filter when making runs. :sneaky:

I absolutely agree. I have the same setup and I do not believe the stock box is restrictive any more. The temp is the first to be worked on.

My next mod will be the t-stat. Need to get the 160 degree one in.
 

·
May I quote you on that?
Joined
·
22,046 Posts
PadreGTO said:
... Here's my setup
OK Spill it, Padre (sheesh, that sounds like a bad western) :rolleyes:
Who, what, where, and how much?
Seriously, that setup make lots of sense. Combining that with Autosport's louvered hood would just about slam the door on the heat issues, and save a few Lbs up front to boot.
 

·
549 RWHP and 569 TQ
Joined
·
414 Posts
I have the MDP hood. It actually has a vent in the back/center to let hot air out. I also got their airbox and combined it with the Speed Inc. tube and cone. I did immediately notice that the box (metal) got very hot to the touch once the engine was hot. I was going to have the airbox ceramic coated which would have helped but it was going to cost $100.

A friend of mine who has a performance shop gave me a role of Tac Mat, made by Dynamat. This is a thermal barrier mat. I cut it out to match the sides of the airbox, sprayed some 3m adhesive on it and attached it to the box. I did not do the lid because I was affraid it might push the hood up on that corner.

I went for a drive on the interstate and hooked up the Autotap. My IAT consistantly read one or two degrees above outside temps. Much lower than before. When I got back home I let the car sit a little bit and felt the airbox. The outside was warn, but nothing like the rest of the engine bay. The inside of the box was very cool compared to the outside. The lid, which I didn't mat at all was no warmer than the outside of the box itself.

I live in Orlando so heat is always an issue, but this setup seems to do pretty good. I may still have the box coated, more for looks than anything else. The Tac Mat is a light pink color, kind of like home insulation. Another reason not to do the lid!

I just got my 160* t-stat so we'll see if that helps with the fans too.

Dave
 

·
Mod Hungry... Empty Wallet
Joined
·
2,137 Posts
mistermike said:
OK Spill it, Padre (sheesh, that sounds like a bad western) :rolleyes:
Who, what, where, and how much?
Seriously, that setup make lots of sense. Combining that with Autosport's louvered hood would just about slam the door on the heat issues, and save a few Lbs up front to boot.
My daughter's BF wants to do the same thing to my car... I am interested in parts too. One last question... Where (and what type) is the filter?
 

·
Resident 10-second Priest
Joined
·
8,959 Posts
mistermike said:
OK Spill it, Padre (sheesh, that sounds like a bad western) :rolleyes:
Who, what, where, and how much?
Seriously, that setup make lots of sense. Combining that with Autosport's louvered hood would just about slam the door on the heat issues, and save a few Lbs up front to boot.
Exactly. That'd be the only interest to me in a new hood: weight and perhaps something that vents the heat.

Who what all that... click on MDMC on your left or PM Sean (OpticZ06) on this forum. Pretty sure I was their first and it was part of the whole package, so don't know about costs for just the unit. But as you'll note on the 3rd pic, it did require cutting, but really not much more than what was there stock and not something that can't be undone by simply replacing the stock box.

Padre
 

·
Resident 10-second Priest
Joined
·
8,959 Posts
Huntress said:
My daughter's BF wants to do the same thing to my car... I am interested in parts too. One last question... Where (and what type) is the filter?
The filter routes below the stock location out of the engine bay and in front of the fender well. It is rather close to the ground, so running through a foot-deep puddle would not be a good thing.

But the filter is just your standard K&N cone filter. I might eventually replace it with a larger one, but it's fine for now.

Padre
 

·
549 RWHP and 569 TQ
Joined
·
414 Posts
mlc said:
wdGTO, You didn't cover the speed inc tube? Did you consider it?
I didn't really think of that. If the adhesive would hold and I could somehow cover the outside so it isn't pink, that might be worth a try. Maybe I could spray adhesive on the outside of the mat as well and put mylar or something reflective on it. I might play around with that. Thanks.

Dave
 

·
Captain Thread Killer returns
Joined
·
21,898 Posts
Wavydavy GTO said:
I didn't really think of that. If the adhesive would hold and I could somehow cover the outside so it isn't pink, that might be worth a try. Maybe I could spray adhesive on the outside of the mat as well and put mylar or something reflective on it. I might play around with that. Thanks.

Dave
Hey Wavy where did you get your TC put in? I am over in Ocala and there are no good places over here.
thanks
 

·
549 RWHP and 569 TQ
Joined
·
414 Posts
Dbluegoat said:
Hey Wavy where did you get your TC put in? I am over in Ocala and there are no good places over here.
thanks
Sent you a PM.
 

·
Registered
Joined
·
267 Posts
Anyone try removing the drivers headlight? (with the stock box of course).

We do it on the Grandprix's at the track to draw more cold air. It looks like the GTO stock box would draw from the same spot.
 

·
Registered
Joined
·
2,691 Posts
Wavydavy GTO said:
I didn't really think of that. If the adhesive would hold and I could somehow cover the outside so it isn't pink, that might be worth a try. Maybe I could spray adhesive on the outside of the mat as well and put mylar or something reflective on it. I might play around with that. Thanks.

Dave
There's a insulator material I saw a while back. It was a self sticky aluminum faced, about 1/8 think, that is used to wrap air ducting in homes. Except for the shiny look I bet it would work great and easy to apply.
 
1 - 18 of 18 Posts
Top