[bogeycentral]

What is this and I noticed that it is part of the requirements for the Jet Stage 2 chip. Trying to get this as a birthday gift from my buddy. I got the free flowing exhaust with straight pipes and thinking of yanking the cats for " a higher flowing option". So just wondering what else will be needed and maybe some different spark plugs. But what is that 180 degree thermostat that Jet Lists on the webpage:

"Stage 2 features more aggressive programming to make the most horsepower and torque available. Fuel and timing curves are extensively modified for peak performance and drivability. Requires use of 91 octane fuel, 180 degree thermostat and free flow exhaust. Also works well with aftermarket intake systems, mass air sensors, TBI spacers, etc"

 

[KenCary]

What is this and I noticed that it is part of the requirements for the Jet Stage 2 chip. Trying to get this as a birthday gift from my buddy. I got the free flowing exhaust with straight pipes and thinking of yanking the cats for " a higher flowing option". So just wondering what else will be needed and maybe some different spark plugs. But what is that 180 degree thermostat that Jet Lists on the webpage:

"Stage 2 features more aggressive programming to make the most horsepower and torque available. Fuel and timing curves are extensively modified for peak performance and drivability. Requires use of 91 octane fuel, 180 degree thermostat and free flow exhaust. Also works well with aftermarket intake systems, mass air sensors, TBI spacers, etc"

Running the engine a bit cooler than the factory 190 or so degrees keeps the heads cooler which helps prevent detonation.

The Jet Chip increases spark advance which can lead to detonation (Knock). If the knock sensor reads detonation, the spark will be retarded, negating the advantage of the Chip.

I used a 160 Jet themostadt in my '94 LT1 Chevy engine for the same reason
Ken. I guess Jet can't go that low in the Nitro.

 

[bogeycentral]

thanks for the info. Pretty simple mod i take it?

 

[KenCary]

thanks for the info. Pretty simple mod i take it?

Normally the themostadt is under the upper radiator hose, but I don't have my Nitro yet.

If it is like most engines, it is messy but simple:

1. Drain about 1/3 of the coolant from the engine
2. Remove the upper radiator hose
3. Undo 2 bolts on the thermostadt housing
4. CAREFULLY OBSERVE POSTION OF OLD THERMOSTAD RELATIVE TO WHICH SIDE FACES THE BLOCK
5. Remove and replace old thermostadt with the 180 Degree one.

If the housing has an O-ring, you can reuse it, if it has a gasket you will need a new gasket.

All in all about an hours worth of work.

Biggest mistake is putting the thermostadt in backwards.

Ken

 

[AirJunky]

Pretty typical mod for any performance upgrade in a wide variety of cars. Might effect your cabin heat at some point.

 

[dk1677]

I wonder about Emissions

engines are designed to run hot to lower emissions I wonder if it might effect any emissions test if you have a state inspection. :thk: < no expert just wondered

 

[bogeycentral]

good thought. currently where I live emissions are no worries and most trucks don't have cats. :Banana01:

 

[KenCary]

engines are designed to run hot to lower emissions I wonder if it might effect any emissions test if you have a state inspection. :thk: < no expert just wondered

I went all the way down to a 160 degree themostat in my LT-1 Chevy and my emssion numbers have allways been way under the NC limits. Always passed.

Most of the Jet stuff is CARB approved so it should be OK for emmissions.

 

[Quiet Lunatic]

Most of the Jet stuff is CARB approved so it should be OK for emmissions.

Ken:

That doesn't necessarily mean there will be a performance gain though. Most of the Jet stuff doesn't give enough hp/torque gain to be worth the money you pay.

JMO, Stewart

 

[KenCary]

Ken:

That doesn't necessarily mean there will be a performance gain though. Most of the Jet stuff doesn't give enough hp/torque gain to be worth the money you pay.

JMO, Stewart

I think you are missing the point here. A 180 theromostat by itself gives no signifcant performance gain.

What it does it pave the way for other mods, like advanced ignition, higher compression nitrous etc.

 

[Quiet Lunatic]

I think you are missing the point here. A 180 theromostat by itself gives no signifcant performance gain.

What it does it pave the way for other mods, like advanced ignition, higher compression nitrous etc.

Agreed. I was commenting on the Jet electronics. The thermostat is a generic thing available widely. The Jet electronics are band-aids to a proper PCM reprogram. I've spent too much time on the Impala Forum and the LT1Edit forum. Getting the PCM properly reprogrammed is better than tricking it into doing something different by falsifying certain inputs. I just don't know if the Mopar computer has been completely de-compiled and re-programming is readily available like for the GM OBDI and OBDII PCMs. If it is Jet is not even a runner. If not it is a band-aid that may give you something for a lot of money.

Stewart

 

[KenCary]

Agreed. I was commenting on the Jet electronics. The thermostat is a generic thing available widely. The Jet electronics are band-aids to a proper PCM reprogram. I've spent too much time on the Impala Forum and the LT1Edit forum. Getting the PCM properly reprogrammed is better than tricking it into doing something different by falsifying certain inputs. I just don't know if the Mopar computer has been completely de-compiled and re-programming is readily available like for the GM OBDI and OBDII PCMs. If it is Jet is not even a runner. If not it is a band-aid that may give you something for a lot of money.

Stewart

To be fair to Jet, they work well on some engines. I saw a dyno test on one on a small Block Chevy Truck and it netted some noticeable gains--- all through ignition advance I am sure.

I bought one for my big block 97 Suburban and it did make a noticable difference. Like you I saw some on the Impala formum that actually lost power with a Jet chip. I'll wait until I read a real dyno test to decide if they are worth anything for the Nitro.

I think on some trucks and non-hi po motors, they program in less advance and the Jet has more effect.

 

[KenCary]

Agreed. I was commenting on the Jet electronics. The thermostat is a generic thing available widely. The Jet electronics are band-aids to a proper PCM reprogram. I've spent too much time on the Impala Forum and the LT1Edit forum. Getting the PCM properly reprogrammed is better than tricking it into doing something different by falsifying certain inputs. I just don't know if the Mopar computer has been completely de-compiled and re-programming is readily available like for the GM OBDI and OBDII PCMs. If it is Jet is not even a runner. If not it is a band-aid that may give you something for a lot of money.

Stewart

BTW one cheap way to trick the PCM into more advance is to put a resistor in line with the IAT sensor. This worked on my daughters Saturn as the PCM thinks the incoming air is cold and it bumps up the advance. This only works on some cars.

Maybe the effect of a Jet module for a 50 cent resistor.

 

[Quiet Lunatic]

BTW one cheap way to trick the PCM into more advance is to put a resistor in line with the IAT sensor. This worked on my daughters Saturn as the PCM thinks the incoming air is cold and it bumps up the advance. This only works on some cars.

Maybe the effect of a Jet module for a 50 cent resistor.

And how much does Jet charge for the ($0.50) IAT module?

Stewart

 

[KenCary]

And how much does Jet charge for the ($0.50) IAT module?

Stewart

Not sure what all the Jet module tweaks in a Nitro, but I think it costs a couple of hundred bucks to get the module.

Does anyone know if the Nitro has an IAT sensor in the air intake? This is a seperate sensor from the MAF. Not all cars have these.

I am all for max ignition advance on the gas I use. In my pre-computer cars I always bump up the static timing until the engine pings and then back it off slightly.

If the Jet module is the only way to do this in the Nitro, it may be worth a couple of hundred bucks. That is small change in today's dollars.

 

[McGuireV10]

This is commonly misunderstood.

Running a 180- or 160-degree t-stat doesn't run your engine cooler.

The temperature rating is the point at which the t-stat valve is fully open. The temperature of your engine probably won't vary much at all unless you've done other things to it which produce a lot more heat. Also, over a very long period of time a lower-temperature t-stat is going to run your water pump harder.

With older engines it was sometimes hard to keep the engine warm enough with an unnecessarily low-temp t-stat, and I suppose that may still be an issue in colder climates.

With regard to engines being designed to run hot, that really isn't the case -- the catalytic converters have to be a certain temperature before they begin to catalyze certain pollutants. At start up your engine computer watches the O2 sensors that are downstream from the cats. As they warm up, the resistance drops. The computer will run a slightly leaner fuel map to warm up the exhaust and put heat in the cats, then when the voltage indicates the cats are up to temp, the regular maps kick in. Engine temp is strictly a byproduct of other activity, not an end-goal in itself.

 

[KenCary]

This is commonly misunderstood.

Running a 180- or 160-degree t-stat doesn't run your engine cooler.

The temperature rating is the point at which the t-stat valve is fully open. The temperature of your engine probably won't vary much at all unless you've done other things to it which produce a lot more heat. Also, over a very long period of time a lower-temperature t-stat is going to run your water pump harder.

With older engines it was sometimes hard to keep the engine warm enough with an unnecessarily low-temp t-stat, and I suppose that may still be an issue in colder climates.

With regard to engines being designed to run hot, that really isn't the case -- the catalytic converters have to be a certain temperature before they begin to catalyze certain pollutants. At start up your engine computer watches the O2 sensors that are downstream from the cats. As they warm up, the resistance drops. The computer will run a slightly leaner fuel map to warm up the exhaust and put heat in the cats, then when the voltage indicates the cats are up to temp, the regular maps kick in. Engine temp is strictly a byproduct of other activity, not an end-goal in itself.

I am sorry but you are wrong about the thermostat. Most engines systems have enough excess water flow and radiator fin area that the themostat does in fact control the engine coolant temperature. Think about it, why else would it be there?

I also have checked my block and head temperature with sophisticated infrared and contact thermal probes and in all cases where I have changed it, a lower temperature thermostat lowered the engine temperature, particularly in the heads.

It is a well known fact of hot rodding that cooler heads are less prone to detonation opening the way for other modifications.

 

[Quiet Lunatic]

What Ken said!

And as an after thought, a lower temp of your thermostat will not impact on the water pump. It runs all the time no matter what the opening temp of the thermostat is. Think about it for a minute.

Stewart

 

[KenCary]

What Ken said!

And as an after thought, a lower temp of your thermostat will not impact on the water pump. It runs all the time no matter what the opening temp of the thermostat is. Think about it for a minute.

Stewart

Let me expand a bit on my last post. Becauuse Mr. McGuire and I actually both have correct points on this subject.

The effect of the thermostat on operating temperature depends on multiple factors, as Mr. McGuire says, it only affects temperature up to the point that it opens. If you are running hard on a hot day, your thermostat will be wide open in most cars whether it is a 195, or a 180. In this situation, both engines will be running the same temperature if the thermostat is open in both cars.

If however, you have enough air flow, and water flow at idle, you are likley to be controlling the engine temp with the thermostat. If your engine is cooler from idle, you will have a cooler engine from a standstill if you are drag racing or looking for a stoplight challenge.

Part of the trick here is to also change the electric fans to kick in at idle earlier than the PCM is programmed for.

When I put in a 160 stat and a manual thermocouple for the fans in my LT-1, I have a measurably cooler head and block temperature at idle and low speed in all but the hottest days.

So in that sense, I agree that changing the thermostat does little for the average guy.

It is also important to note that some PCM's will sense coolant temp and if lower, they will sometimes give more spark advance also leading to more power.

Suffice it to say that there is a complex interaction here and don't mess with the themostat unless you understand your end goal or purchase a chip, themostat, and fan kit that is designed and tested to work together to add power.

Mr. McGuire, if you are a road racer rather than a drag racer, you might never gain an advantage from a lower temperature thermostat. However, for a straight-line guy, a few degrees cooler at idle can make a lot of difference.

Ken

 

[Dolphin1]

With regard to engines being designed to run hot, that really isn't the case

it is the case and its done to reduce emisions and it helps reduce cylinder wall wear.it aslo helps improve fuel milage.

Mike