Breaking 13 seconds [Archive] - Cherokee SRT8 Forum

: Breaking 13 seconds


FastJeepSRT8
05-19-2007, 02:01 AM
Now that I've been to the track I know I'm 13.1 to 13.2 sec in the 1/4. Is it possible to break 13 sec with bolt-ons? My next move will be exhaust and intake. Could this be enough to do it or will I need to do more? Just currious.

GotStroke?
05-19-2007, 02:41 AM
Several (at least a handful) have gone 12.8-12.9@104-105 with just a T-stat and/or fan mod and good air.

FastJeepSRT8
05-19-2007, 02:46 AM
Several (at least a handful) have gone 12.8-12.9@104-105 with just a T-stat and/or fan mod and good air.

So it sounds like the mods I mentioned should do the trick. Hasn't SRT engineering advised against the cooler T-stat claiming they designed the Jeep to run hot. I read something about that in another thread that SRT responded to. I also believe that SRT claimed they had not actually tested the lower T-stat.

GotStroke?
05-19-2007, 03:20 AM
So it sounds like the mods I mentioned should do the trick. Hasn't SRT engineering advised against the cooler T-stat claiming they designed the Jeep to run hot. I read something about that in another thread that SRT responded to. I also believe that SRT claimed they had not actually tested the lower T-stat.


The best advice I can give you is to ignore what the SRT engineers say. They're on a short leash so to speak; imagine the potential warranty/liability/emissions implications.
More members than I can count have successfully used a cooler T-stat (MotoRad/Valucraft 383-170 or 383-180 (176*-180)) and found power. We're talking about a solid 2 tenths in the quarter when combined with the also dirt cheap fan mod.
Those same engineers also state that the full factory exhaust is optimal. :rolleyes: Etc, etc. etc.

BuilderBill
05-19-2007, 05:39 AM
More members than I can count have successfully used a cooler T-stat (MotoRad/Valucraft 383-170 or 383-180 (176*-180)) and found power. We're talking about a solid 2 tenths in the quarter when combined with the also dirt cheap fan mod.
Count me as one of those that went from 13.2 to 12.85 for almost no money. 170* when used above 60* ambient will not throw a code either. This does NOT mean that your JGC will be at 170* while driving....it still reaches 200* range.

Can't believe with this being posted dozens upon dozens of times guys would hesitate to do a simple mod that may take an hour or so for the fan mod (see FAST writeup) and the thermostat change.

The next mods get more expensive,,,Dana 60, supercharged 426 low compression engine, user programmable electronics etc.:eek::eek:
Bill

srt8hotrod
05-19-2007, 05:40 AM
do the stat it works, its cheap to do and the thing does run cooler!!

DavesSRT8
05-19-2007, 05:54 AM
My personal experiences so far (at just 700 miles)

Stock:
13.378 @ 102.61
13.286 @ 102.81
13.308 @ 102.89

changed to 180 thermo, same track (Etown), almost exact same ambient temps, cooldown time, etc. (Dashhawk used to make sure temps were cooler). Efan installed and turned on via switch (Hi side). 60 foot times were about the same also, 1.8-1.9 ranges

13.062 @ 103.67
13.040 @ 103.82
13.048 @ 103.83
13.077 @ 103.44

1/8th mile times went from 8.5's to low 8.3's.

Total cost:
$11.99 for Autozone thermostat (Valuecraft)
Already had wire/switch for fan mode = $0.00

TOTAL: $11.99 to pick up 3/10's in 1/4. With more practice on the 60 foot (the 'normal' rule = 1/10 in 60' = 2/10 in 1/4) I believe this is a 12 second Jeep. In fact, Dashhawk is showing better times now that I've found the sweet spot for the powerbrake - 1800 RPM = 3.93 sec 0-60, consistently. Can't wait to get back to track and try again.

Love this thing.

Dave
2007 GCSRT8

FastSRT8GC
05-19-2007, 08:46 AM
Use my link below for the Fan Mod. It will help a ton. This motor is extremely prone to Heat Soak. We ran water on the intake for 20mins and let it cool down for 45min. I gained 1.2 sec. If I had the fan mod at the time I would have been in the 12.s for sure. Also Ice it down if you can. Two bags of ice on the intake will help.

I also believe these motors are slightly starved for air from the factory. The CAI and the exhaust will help it breath much better. OH and move your ITA into the intake box to lower its readings!

Good Luck

awdrocks
05-19-2007, 10:02 AM
Count me as one of those that went from 13.2 to 12.85 for almost no money. 170* when used above 60* ambient will not throw a code either. This does NOT mean that your JGC will be at 170* while driving....it still reaches 200* range.

Can't believe with this being posted dozens upon dozens of times guys would hesitate to do a simple mod that may take an hour or so for the fan mod (see FAST writeup) and the thermostat change.

The next mods get more expensive,,,Dana 60, supercharged 426 low compression engine, user programmable electronics etc.:eek::eek:
Bill

Question: What temps do the motors get without the t-stat mod? I think the usual rule of thumb is that motors usually make their most available power at just about 200*. Does the stock setup go beyond that? Or do these Hemis make more power @ 170-180ish*?

Also I think you guys would have a lot to benefit from spraying meth/water into the intake stream... and make the ice on the intake a thing of the past.

gbusy1906
05-19-2007, 10:43 AM
Is this setup simular to the ESP FAN MOD by GSM? I purchased one a few months back and decided not to install due to warranty concerns. Now I am having second thoughts.

My best time w/o it is 13.03 at 101.60 w/ a 1.78 60ft

K

candyman
05-19-2007, 10:56 AM
Question: What temps do the motors get without the t-stat mod? I think the usual rule of thumb is that motors usually make their most available power at just about 200*. Does the stock setup go beyond that? Or do these Hemis make more power @ 170-180ish*?

Also I think you guys would have a lot to benefit from spraying meth/water into the intake stream... and make the ice on the intake a thing of the past.
Normal operating temp for these motors is around 215*.

awdrocks
05-19-2007, 11:08 AM
Normal operating temp for these motors is around 215*.

What temp t-stat is stock?

SilveRT8
05-19-2007, 11:21 AM
What temp t-stat is stock?

203*
Claude

awdrocks
05-19-2007, 11:50 AM
203*
Claude

So the 180* t-stat gets the motor closer to the lucky number of 200*.

I'm very impressed with these STR8's. GREAT stock E/T's.

FastJeepSRT8
05-19-2007, 11:52 AM
Thanks for all of the info! The coolest I ran all night was 195 after about 40 min of cooldown time. This track is in the middle of nowhere so I wasn't able to pick up any bags of ice. The rest of the night I ran anyehere from 220 to 240. I will definitely do these mods. Thanks to everyone here for your help.

BuilderBill
05-19-2007, 04:36 PM
Thanks for all of the info! The coolest I ran all night was 195 after about 40 min of cooldown time. This track is in the middle of nowhere so I wasn't able to pick up any bags of ice. The rest of the night I ran anyehere from 220 to 240. I will definitely do these mods. Thanks to everyone here for your help.
Come on FastJeep...we are looking after your best interests!!!
Throw in the 170* and the fan mod and run 12.mideight or lower.
We DO want to make you look good at the track! It shocks people...
Bill

Inferno SRT8
05-20-2007, 02:15 PM
Now that I've been to the track I know I'm 13.1 to 13.2 sec in the 1/4. Is it possible to break 13 sec with bolt-ons? My next move will be exhaust and intake. Could this be enough to do it or will I need to do more? Just currious.


Im proof that you can and will!

12.6's all day at Etown this weekend! In positive DA!

generalconfusion
05-20-2007, 07:17 PM
Im proof that you can and will!

12.6's all day at Etown this weekend! In positive DA!

Tony........I think you mean negative
Englishtown is 55' above sea level

http://www.na-motorsports.com/Tracks/NJ/OldBridge.html#DragTimes

On Friday May 18th
Altitude-55 ft above sea level
temps- 51
altimeter- 30.09
Dew point- 39
DA was -554

Saturday May 19
the DA averaged -47 until 11:00am and was at -217 at 8:00pm

Those are great conditions.....no wonder you guys run such sick times!!!


http://wahiduddin.net/calc/calc_da.htm

Inferno SRT8
05-20-2007, 07:34 PM
Tony........I think you mean negative
Englishtown is 55' above sea level

http://www.na-motorsports.com/Tracks/NJ/OldBridge.html#DragTimes

On Friday May 18th
Altitude-55 ft above sea level
temps- 51
altimeter- 30.09
Dew point- 39
DA was -554

Saturday May 19
the DA averaged -47 until 11:00am and was at -217 at 8:00pm

Those are great conditions.....no wonder you guys run such sick times!!!


http://wahiduddin.net/calc/calc_da.htm

Steve the temp saturday was 64 the altimeter was 29.15

Im using the same calculator and I come up with +1392'

Am I doing something wrong?

generalconfusion
05-20-2007, 09:09 PM
Steve the temp saturday was 64 the altimeter was 29.15

Im using the same calculator and I come up with +1392'

Am I doing something wrong?

Tony,

I saw you called.....I was busy getting my son ready to go back to his mothers.....ok

You enter the city and state and scroll down to "History and Almanac" you will find the time of day......temperature....Dew Point.......and Pressure those are the keys.

http://www.wunderground.com/cgi-bin/findweather/getForecast?query=Englishtown%2C+New+Jersey

Then enter that information in the boxes with track elevation.

http://wahiduddin.net/calc/calc_da.htm

Call me if you think I messed it up.......now that my kid is gone I have to activate the TIVO for the Soprano's!

Inferno SRT8
05-20-2007, 09:50 PM
Steve on yours I get the above said DA and on this one I get +1389

http://www.modulardepot.com/density2.php


64 Degrees
40% Humidity
Track eleveation 55'
Baro Pressure 29.15

generalconfusion
05-21-2007, 12:32 AM
Steve on yours I get the above said DA and on this one I get +1389

http://www.modulardepot.com/density2.php


64 Degrees
40% Humidity
Track eleveation 55'
Baro Pressure 29.15

I dont believe you are +1389.......that track wont see something like that until say July thru August......the DA that is......I could be wrong but from what i have read and understand. I think your Baro # is wrong......that area has had a 29.9 pretty consistently

On Saturday at 11:00am
Temp 55
Humidity - 48%
Track Alt - 55
Pressure - 29.99

Negative 184


http://www.modulardepot.com/density2.php

Are you using the National Weather Site? It shows every city or location for every hour and has historical data as reported at the nearest weather station in that location.

http://www.wunderground.com/cgi-bin/findweather/getForecast?query=Englishtown

Inferno SRT8
05-21-2007, 07:31 AM
I dont believe you are +1389.......that track wont see something like that until say July thru August......the DA that is......I could be wrong but from what i have read and understand. I think your Baro # is wrong......that area has had a 29.9 pretty consistently

On Saturday at 11:00am
Temp 55
Humidity - 48%
Track Alt - 55
Pressure - 29.99

Negative 184


http://www.modulardepot.com/density2.php

Are you using the National Weather Site? It shows every city or location for every hour and has historical data as reported at the nearest weather station in that location.

http://www.wunderground.com/cgi-bin/findweather/getForecast?query=Englishtown


Steve right off the weathen channel 29.15 :D

The DA for sunday was +2000 according to guys that were running sunday! Everyone was complaining the air went to crap sunday, worse then saturday.

generalconfusion
05-21-2007, 01:17 PM
Steve right off the weathen channel 29.15 :D

The DA for sunday was +2000 according to guys that were running sunday! Everyone was complaining the air went to crap sunday, worse then saturday.

There you go .....thats the problem! You have to measure barometric pressure at sea level at the location. Weather is a factor but the barometric pressure will determine air density. You would have to have a huge storm over the Freehold Borough area to see a low in air pressure! Barometric pressure for that area never went that low. That whole region for the most part is at sea level or just above. Barometric pressure is extremely high in that region....even now as I write this is, it is one of the highest in the Nation! If that is crappy air my friend........ship it to California Speedway this weekend!!

I dont know who got what that day but the historical data taken from the weather stations for that area are as accurate as they get and that is what pilots use. Englishtown is in Freehold Borough........and this historical information is it.

Tony, The point here are the gains from the B&G and we both have experienced them. All you guys on the East Coast have the quickest times, and that includes, Chevy, Chrysler and Ford..... but it isnt because the car manufacturers send slower cars to Colorado and California.

Here is the history for Friday by the hour!! For Friday May 19th
http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KNJFREEH3&month=5&day=19&year=2007

History by the hour for Saturday May 20th
http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KNJFREEH3&month=5&day=20&year=2007

Sunday must have had some really good times
http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KNJFREEH3&month=5&day=21&year=2007

BuilderBill
05-21-2007, 02:30 PM
Nice research general!
Bill

cobrakid
05-21-2007, 03:14 PM
......you guys are too serious. When at the track all day yesterday.....

I ran 12.41@109 w/1.67 60ft, and thought, "Hey, it was 2 tenths slow that
day for all of my big racing buddies that document their repeatable runs within
hundreths, and think to myself. That was ok." Was a little hot & muggy.

I do think, traction pemitting, and a good "air" day with temps in the high 40s
to low 50s, I could squeak some 12.2s@111???????

...but I admit, it urks me when I can't repeat close to my best every time.

I ran 12.6s@106 all day 2 weeks ago, b/c I moved my IAT sensor back in the
top of the airbox lid. The only thing I changed was putting it back, and my
times and mph came right back. I think it must be a nitrous thing?????

GotStroke?
05-21-2007, 06:32 PM
Again, weather doesn't affect your runs nearly as much when spraying.

cobrakid
05-21-2007, 08:06 PM
nitrous makes it's own weather.

GotStroke?
05-21-2007, 09:37 PM
nitrous makes it's own weather.


Perfectly stated.