It should be worse!

[ViperGeorge]

Regarding the tow hooks it is hard to say what they do to the aero, a small change could be significant but maybe not. When you remove them I'd remove the entire thing.

Same with the grille. What's behind the grille? Do you think removing it or cutting out the V would increase airflow? At least the tow hooks are an easy change, and if you cut out the grille you could tape up the V session to session to see if there's a difference.

Aero is funny and can either be numb to changes or super sensitive to a seemingly minor change. In IndyCar radiator blockers are internal to the sidepods and are adjusted all the time to get the ideal temperatures, sometimes only by fractions of an inch to change 10s of degrees. 70 degrees C water (or as cool as possible) and 110-115 degrees C oil temp are ideal for power on those engines but sometimes they run water hotter to reduce drag induced by extra cooling.

I believe there are some metal braces behind the grille that would look unsightly if exposed. I will have to check to be sure. I wish someone would make a better looking grille that also improves airflow. The OEM grille is $140 for a reason, it looks and feels cheap.

[XSnake]

Here is some data at Indy GP Course, as you can see lap 7 and 8 ect temps rose to 241, this happened around 5 out of 8 sessions for the weekend. Ive put the 241 lap in red and listed ect, iat, rpm, throttle position. The car does seem to cool down on its own on the long straights which is good, indy gp is full of 2nd gear turns, which probably dont help. Those laps was about 6-7 seconds off my fastest laps so im guessing there was possibly traffic, im starting to wonder how much being behind another car effects airflow? Ill put a gauge on my video for ECT next time to see what happens.

I'm not familiar with that track but I would be willing to bet that you could take some of those 2nd gears turns in 3rd and actually be faster. Especially with having 3.55's in the Gen V's. There are very few turns that you need to be in 2nd gear going through in a Viper with the amount of HP and TQ these cars produce. Going through in a higher gear will also get you to work on entry and mid corner speed and keep you from trying to make up for that time by trying to hammer it out of the corner. Sure, it feels cool but it's not necessarily the fastest way around the track and it's definitely not the easiest on your car. Smoother is faster.

[VENOM V]

245 is only 10 degrees from 255, that seems pretty close to me as it is only an additional 4% increase. I think if I ran the car hard in a double stint I might very well reach that. As it is when the car gets over 240 I back it off. Maybe next time I will keep pushing to see how close to 255 it does get. On the other hand what happens at 255? Does the engine go boom or does it got into to limp mode? Either would be bad if in traffic at speed on the track.

George,

If I hit 240 F water again, I plan on continuing to push hard and will only back off if I hit 245 F. I run an AIM data acquisition system like Imcgrew79, and will record all temp data. In his case, it looks like the car reaches equilibrium and doesn't continue to heat up. I'm with you, I don't want to find out what happens at 255 F, but I doubt anyone will hit that. Thermal systems eventually reach a steady state, at which point the temp will stop climbing.

I run a tow hook too, FYI.

[SSGNRDZ_28]

Remember the radiator relies on air movement through its grills to cool . If to much positive air is building up behind the radiator it could be impeding cooling . The needs a way to keep flowing once its past the radiator. We work with this a lot on our race cars .

This is true but with a higher flowing radiator already tried (it seemed to cool to a certain level faster but hit a wall at speed), and hood vents removed, etc. it seems the restriction is in the opening of the grille or incoming air not the outlet.

[Bugman Jeff]

Since the bigger radiator didn't really help, could it be a water flow issue either too much or to little? Would it be worthwhile to remove the thermostat and test water restrictors of various sizes starting at no restriction and working down past the stock thermostat?

Would it be feasible to put some air pressure sensors on either side of the radiator to see how much pressure drop there is from one side to the other at speed? That might at least tell you if outgoing airflow is the problem.

[SSGNRDZ_28]

Unless I've missed it nobody's car has gone into limp mode. Nobody's car has overheated. However, at these higher temps performance is reduced (at least marginally) by pulled timing. This thread should hopefully find a way to reduce temperatures in order to improve performance for those who are having an issue or for those who desire increased performance via improved cooling.

Since the bigger radiator didn't help, could it be a water flow issue either too much or to little? Would it be worthwhile to remove the thermostat and test water restrictors of various sizes starting at no restriction and working down past the stock thermostat?

That's another possibility as suggested by TrackAire several posts back. Flow that is too fast or slow and another good test for someone to try but maybe not as easy to back to back. Maybe start with no restriction and then try a step more restriction than OEM to get a direction.

[Snakebit10]

If Winkles says 255 degrees is safe limit then why is everyone worried about 24x degrees after admitted many laps at 8 - 10/10's driving? How many Vipers did a Vette imitation and quit at these 240 temps?

[VENOM V]

If Winkles says 255 degrees is safe limit then why is everyone worried about 24x degrees after admitted many laps at 8 - 10/10's driving? How many Vipers did a Vette imitation and quit at these 240 temps?

This is my opinion too. I've not heard of a single Viper go into limp mode for overtemp.

Chris mentioned that Tommy Kendall went into limp mode at Viper Tracks. This is because he bounced off of the rev limiter three times consecutively, and I hope my car goes into limp mode too if ever I abuse it that way, LOL

[Jack B]

Your post ruined this thread, wait, the majority will ignore good info and continue to confuse/ruin a good thread.

No dis to those that posted legit data.

If Winkles says 255 degrees is safe limit then why is everyone worried about 24x degrees after admitted many laps at 8 - 10/10's driving? How many Vipers did a Vette imitation and quit at these 240 temps?

[Stealth]

It's like I'm reading about some other model of car, these stories are foreign to me. How can it be that for two years I've been tracking my Viper and this month is the first time I've heard of this "overheating" issue? I tracked at Laguna Seca recently with 17 Vipers. No one overheated except for the C7 Z06, which went into limp mode and puked all of the coolant out right next to me in the paddock. He hit 267 F water and 309 F oil. Buttonwillow with 78 Vipers, no overheating issues on a single car. 2 C7 Z06s in limp mode at Buttonwillow in cool weather. I've tracked with other Vipers in 107 F and no one overheated. Laguna Seca, Buttonwillow, Thunderhill, Sears Point, Spring Mountain. Never had an issue other than touching 240 F coolant at Thunderhill in 106 F ambient, so I backed off for a lap and it immediately cooled. Then went hard for another 5 or 10 minutes and never touched 240 F water again. I did have an 02 sensor go that day, replaced under warranty the next week. Easy peasy. The only issue I've ever had with the Viper was that 02 sensor, no melted wires, no other issues at all. I just change the oil and brake pads, and an occasional alignment. And drive the wheels off of it, over 14,000 miles many of which are on the track.

This all seems blown out of proportion, only a couple of folks have had issues. As Darius said, Camaros run hot as his Z/28 hit 290 F oil (my modded Camaro required 2 oil coolers and custom shrouding to get the oil temps reasonable), C7 Vettes run hot. But I haven't seen it with Vipers.

And I know that this has been said, but to remind folks that Dick Winkles stated to keep the coolant temp below 255 F and oil below 300 F. I am nowhere near those values and I haven't read anyone else approaching them either.

+1 No evidence of "overheating"--just well-running Vipers! Todd's experience exactly mirrors my experience, although I have run only 2 separate days.

[Stealth]

There are 2-3 reported stock cars that seem to be running hot in this thread while tracking. This is hardly an epidemic for stock vehicles. Plenty of guys beating their cars to death not having issues running stock.

Majority of reported issues seem to stem from cars that are modified, from PCM to headers. While it sucks for them, it is a bit different than discussing stock cars running hot.

And as FLATOUT has said, the car even at 250* is far from hitting limp mode which is plaguing the Z06s.

Being said, hopefully it is something minor.

Actually, the stock cars reach the same temps as some of the modded cars--hotter than cruising on the street, but not overheated. The issues on the modded cars (thus far) appear to relate to melting of wires from headers, etc.

I ran my '14 GTS stock once in 72F weather and once with Arrow PCM, Corsa Exhaust and TA Bars in 85F weather. Temps were slightly higher on the hotter day as expected. No problems either day and no "flashing lights" noted either day at 240F Oil.

[ViperGeorge]

Actually, the stock cars reach the same temps as some of the modded cars--hotter than cruising on the street, but not overheated. The issues on the modded cars (thus far) appear to relate to melting of wires from headers, etc.

I ran my '14 GTS stock once in 72F weather and once with Arrow PCM, Corsa Exhaust and TA Bars in 85F weather. Temps were slightly higher on the hotter day as expected. No problems either day and no "flashing lights" noted either day at 240F Oil.

I am not sure that anyone has continued pushing the car hard once the idiot light flashes at 240. Maybe if we did the temps would stop rising at 245 and equalize as has been suggested by Venom V or maybe they would keep rising to some higher level. I don't think anyone knows for sure. Personally my car hit 243 when I had to back off because it threw a code for an accelerator pedal sensor (actually turned out to be the harness). At that point though it did not show any signs of stabilizing and this was only after about 15 minutes in 77 degrees ambient.

[lmcgrew79]

I'm not familiar with that track but I would be willing to bet that you could take some of those 2nd gears turns in 3rd and actually be faster. Especially with having 3.55's in the Gen V's. There are very few turns that you need to be in 2nd gear going through in a Viper with the amount of HP and TQ these cars produce. Going through in a higher gear will also get you to work on entry and mid corner speed and keep you from trying to make up for that time by trying to hammer it out of the corner. Sure, it feels cool but it's not necessarily the fastest way around the track and it's definitely not the easiest on your car. Smoother is faster.

Yeah i agree with that except that track has 5 45-65 mph turns, 3rd gear is slower out of those turns, the gen 5 with the 355 rear gear also has a completely different geared transmission than the gen 4 to match. 1st second and 3rd gears result similar speeds as the gen4.

[Nemesis]

You say you have experienced overheating but didn't mention any coolant or oil temps. Melting wires is an issue separate of the elevated track temps, take the proper precautions and you're good to go.

230-248 Water 280-300 Oil. Melting wires even when wrapped is not a separate issue, it is directly correlated. Especially when melting at 240 which double wrapped lines. Last time I melted down the GTS I wasn't even at the track.

[ViperGeorge]

230-248 Water 280-300 Oil. Melting wires even when wrapped is not a separate issue, it is directly correlated. Especially when melting at 240 which double wrapped lines. Last time I melted down the GTS I wasn't even at the track.

Wow, those are the hottest temps I've heard of yet. What mods, if any, does your car have?

[FLATOUT]

230-248 Water 280-300 Oil. Melting wires even when wrapped is not a separate issue, it is directly correlated. Especially when melting at 240 which double wrapped lines. Last time I melted down the GTS I wasn't even at the track.

Your last sentence, you melted wires on the street with normal operating temps?

[BLUETA#1]

So if we cut out the honeycomb in the V that should add some airflow. It won't be a "Flowtie" it will be "FlowVie".

Good one!

[BLUETA#1]

Being behind a car effects airflow immensely. It doesn't mean you have to be on a bumper. Draft starts many car lengths back. Draft =bad airflow for the radiator but good for aerodynamics. Us racers are always watching temps when we are in a pack drafting with bad airflow.

You are correct. I am seldom behind a car for long. I try to head out first onto the track and maybe a jacked up GTR gets me or an old cup car, but when they pass, they are by me fast.

[BLUETA#1]

Blue, do you have any vids or data of you lapping?

I have my second session on track….2:32 best lap and the temp was about to hit 240. I have managed to lower the temp a bit….from 2:32-34 lap times @ 240 to 2:28-29 @ 240. I can run 1-2 laps at 2:24 and I have to shut her down. I was going to post it, but I was getting flamed so bad, I did not want to expand the discussion into my driving. PM me if you want the link.

[BLUETA#1]

Like Mjorgensen NineBall and multiple others have suggested it is time to open up the front by reducing restrictions. Tow hooks are easy, but can the black portion of the grille be removed without being destroyed as a test or is it a structural part of the car? Looks like it only costs ~$100 (P/N 68141085AB) so buying one to cut up wouldn't be the end of the world. If that works it would be up to the user to modify his / hers or the aftermarket to come up with something that bolts in, or just have a cutout one for the track if it isn't too painful to install.

I have a new front grille in the box in my garage ready to hack up. Not sure how to do it. One thing that I have to say….the Viper parts are super reasonable.

[BLUETA#1]

George,

If I hit 240 F water again, I plan on continuing to push hard and will only back off if I hit 245 F. I run an AIM data acquisition system like Imcgrew79, and will record all temp data. In his case, it looks like the car reaches equilibrium and doesn't continue to heat up. I'm with you, I don't want to find out what happens at 255 F, but I doubt anyone will hit that. Thermal systems eventually reach a steady state, at which point the temp will stop climbing.

I run a tow hook too, FYI.

I plan to run past 240 to see if it goes any higher. I will let it get to 245 tops. Then I will do an ECU swap. Last move will be to pull the entire front grill off. New car is not here until March and I have 5 track days until then. Next will be to run stock tires. I will keep trying.

[ironpeddler]

Keep it up Blue...don't let the haters get to you. I appreciate what you are doing and I am sure others do also. I am hoping that you will find the solution.

[ViperSmith]

Keep it up Blue...don't let the haters get to you. I appreciate what you are doing and I am sure others do also. I am hoping that you will find the solution.

No one it hating, stop being obtuse

[Snakebit10]

I have my second session on track….2:32 best lap and the temp was about to hit 240. I have managed to lower the temp a bit….from 2:32-34 lap times @ 240 to 2:28-29 @ 240. I can run 1-2 laps at 2:24 and I have to shut her down. I was going to post it, but I was getting flamed so bad, I did not want to expand the discussion into my driving. PM me if you want the link.

I don't recall you mentioning that your car is cutting out or not operating well while at those temps (240-245 degrees). It seems that once it hits that temp range you decided it was too hot and did cool down laps. It seems as if the engineer stated that 255 degrees is a safe limit for the car. In other words it seems designed to operate safely up to those temps. So if nothing it going wrong with the car at those temps and its still turning in those 2:24 laps times then it would seem you could have done a few more laps before/if it hit the 250+ temp range. Has anyone got it up to 255 degrees on track? If so what happened at that point? Just wondering if we are using temps from other cars as a measuring stick for this car. For instance the G4 Vipers were in the 210 temp range but the G5 runs hotter so we might think the G5 needs to be 200-210.

When a car overheats it quits a la Vette. These Vipers running 230-245 are still running from what I'm reading so I'm not sure the car is overheating especially after what the engineer has said is the safe limit. Wanting cooler temps is great but if the car is designed with that operating temp range we might be making more of this than necessary? Just thinking out loud from a different perspective on this issue. I reserve the right to be wrong.

[ACR Steve]

Personally I think its the air flow on the back end of the radiator that's causing some of the issues. I haven't received my Gen 5 yet but everyone says how much tighter it then the 4. Radiator needs the flow behind to properly draw air through.