Heat Soak on Paxton S/C SRT-10

[rleminv]

I've read with interest many of your comments about heat soak and the S/C'd Viper. My Viper will be back in my hands hopefully in about 30 days and I will be renting a strip to practice my launches and 1/4 mile. It's been years since I have done this and I need soooo much practice. Way to embarrassed to try this during a real event with only my 40 year old memories. A few questions, if they're dumb, please forgive this old guy.

1. Driving approximately 90 freeway miles to the strip, any best guess as to loss? How much difference will trailering affect the first runs?

2. Back to back runs and starting and stopping of motor waiting to stage during normal events. How should I expect this to affect and can our large blower fan help in the pits? Normal event waiting rather than my practice, hour or more, will this help recovery?

3. Normal street driving in 75F then forced by the devil and a gun to my head to a race?

4. What is the larger aftercooler with chrome visible through the front? Is this an aftermarket item I can purchase or does it need to be fabricated. Does it even really help?

Thanks everyone, it's time I stop being a poser for at least a little while.
Larry

 

[2002_Viper_GTS_ACR]

1. While moving and getting plenty of air, your not going to heat soak. Its when you sit idling, or driving in traffic, or multiple bursts in hot days, or leaving the car in its power band while driving on the high way (like 3rd or 4th, instead of cruizing in 5ht or 6th). Trailoring will help for the FIRST 2 or 3 passes, after that, you will have put the heat into the motor and the S/C. (So just do a few passes, then give cool down time, hood up, and wait 40 mins to 1 hour if you want it really cool for best pass)

also you can get to the track earlier (after you drove there) be the first one in line, with your car off hood up, and your first pass will be AWESOME, unfortunetly if you dont hook, it will be a wasted first pass, which will be your coolest motor run probably)

2. Back to back runs cause heat soak, but its the truest numbers, as they show the worste your car could possible do when its soaked ! Cooling will help, ice the intake and ice the after cooler (I dont like doing either, as its total [******], you will never be on the street with ice on your intake or after cooler, but it definetly will help 1/4 mile times) also you can put ice cubes in the filler portion of the after cooler

3. I dont really know what your asking in 3, if your asking what happens after driving in 75F weather, and then you nail the gas, you will be fine, if its on a high way, and your motor has been staying cool from all the air flow coming in.

4.I dont know who readily has aftercoolers that pop right in, maybe someone can respond, but you will need a water to air cooler, as thats what the paxtons are plummed for stock, otherwise to convert to air to air, will take some work. I dont know if its going to help a ton or not, depends on how hard you are going to drive your car, I dont think its worthwhile for you.

Jon
PS. If you want to chat on the phone just pm me, and I'll give ya a call. This is my second S/C'ed viper I have now.

 

[Paul Hawker]

Larry.
You will probably have the problem of too much HP even when running hot. If you are on stock run flats you will have more of an issue of traction than power. Since you have not run the track in a while the lowered hp from the heat may be a blessing in disquise.
Do not lower your pressure in run flats. Because of the hard sidewalls, you will just get cupping and run on the outside edges. Might want to do a short burnout on the street, and take a look at your tire patches. Add a few pounds and see which gives you a better pattern.
Have a great time at the track. First time I ran my Paxton on a slippery course (Phoenix) I was feeling tire slippage even when crossing the finish line. Lots of power with the Paxton setup.
Might want to give Cragin a call to pick up some dragstrip tips. He knows all the hot setups.

 

[rleminv]

Paul, Thank you and I do plan on calling Dan. I'll be running the BFG drag radials on 18" Purners.

Jon, You have a PM.

 

[2002_Viper_GTS_ACR]

Paul, Thank you and I do plan on calling Dan. I'll be running the BFG drag radials on 18" Purners.

Jon, You have a PM.

And you have a response

 

[Vic]

If you do the 1/4 mile at California Speedway, cool down should be no problem. (It takes 8 hours to get three runs in)

 

[pumpgas]

Put on methanol injection and be done with it. Adds a huge measure of safety as well.

 

[rleminv]

If you do the 1/4 mile at California Speedway, cool down should be no problem. (It takes 8 hours to get three runs in)

LOL

Thanks Vic, my exact reason for renting it for a day. AAA Speedway during any events don't lead to anything but boredom for me while attending my son's races. You got three runs in? Last time we got (our team) two runs then disqualified for missing the scales (weighing each corner until permanent one installed). We were waived through while another car from a previous race was being weighed; the loser of our round complained and...couldn't fight it - disqualification after one of the best runs for the new motor. Knowing it takes lots of practice and muscle memory, I figure at my young age I'll take the memory part of the equation out of it.

Pumpgas thanks for the tips. WM, 12# pulley and Racelogic are being installed as I type. Doesn't mean I don't need your input. My Viper's set up is only because I have had great input from many very enlightened people. I certainly don't know it all and what I remember is when us kids got excited when a 200mph 1/4 was achieved! You may think the Viper a simple beast, it's still light years ahead of our small block chevys!

 

[Vic]

Thanks Vic, my exact reason for renting it for a day. AAA Speedway during any events don't lead to anything but boredom for me while attending my son's races. You got three runs in? Last time we got (our team) two runs then disqualified for missing the scales (weighing each corner until permanent one installed). We were waived through while another car from a previous race was being weighed; the loser of our round complained and...couldn't fight it - disqualification after one of the best runs for the new motor. Knowing it takes lots of practice and muscle memory, I figure at my young age I'll take the memory part of the equation out of it.

Wow, very frustrating.... Have you tried road racing? 2.5 hours a day is more than enough excitement for me!

 

[rleminv]

Wow, very frustrating.... Have you tried road racing? 2.5 hours a day is more than enough excitement for me!

Figure I should crawl before running. Though I never have done it, I would think road racing is much more demanding and much more to learn. Give me time, I really would like to run the Silver State eventually.

Larry

 

[Bolt]

Put on methanol injection and be done with it. Adds a huge measure of safety as well.

What kind of safety does methanol injection give you? Details please.
I have heat soak problems which I will be fixing soon and looking at my options.

 

[PaViper]

my guess would be the safety factor he is talking about would be the cooling effect it has on the pistons....the down side is unless you have a monitoring system, you get the opposite effect when it fails

 

[Twister]

I honestly wouldnt worry too much about heat soak...

It seems that most paxtons on a bone stock SRT10 dyno 615-640 rwhp...130-135 mph trapps

With severe heat soak you'd still be in the 565-615 range on a stock SRT10...127-132 mph trapps

The stories you here are of someone running there paxtoned SRT10 against a forg GT...Z06..yadda yadda yadda ...7-10 runs back to back on the freeway..

In this case...I could see the paxton'd viper heat soaking to the point of 525 rwhp ( a loss of 100 rwhp ) while the EXMP. Z06 has probally only heat soaked from 455-425 rwhp ( a total loss of 30 rwhp)...

The Paxtoned viper would still win on these heat soaked runs. But it aint running away..Like it dose with a 200 rwhp advantage at 6XX rwhp VS 455 rwhp when there's little heat soak

 

[Twister]

Bt the wayy...In the heat soaked stories of multiple runs the Z06 usually has mods and even a cam...

In this case you'd have a multiple highway runned 525 rwhp paxtoned SRT10 VS a cammed Z06 that is heat soaked as well but only loosing 30 rwhp and still dynoing 480 rwhp..

And yes..Like story tellers have said it would be VERY close...

But again. Under normal conditions the 6xx rwhp paxtoned viper will run away

 

[Jsparks]

can heat soaking cause damage to the engine or is just a power issue?

 

[Joseph Dell]

engine temp being at 210-230 isn't a problem by itself. but a hot engine is more prone to pre-ignition / detonation than is a cold one. So if your tune is 'on the edge' and you run a hot car at the track and you aren't paying attention to whether the car is knocking or it's A/F ratio, then you could hurt the engine. but just being hot isn't going to hurt anything. you'll be down a tad on power, but that's it.