What are some ways one could go about lowering their Exhaust Gas Temperatures? My EGT's during normal driving normally hover around the 1200 degree mark and under heavy acceleration, if only for one gear, even, can reach upwards of 1500 degrees. I understand that at 1500 degrees it's very possible that one could crack a piston and I can't even wind out a single gear without getting close or exceeding that temperature.

Once again, what are some way one could lower EGT's reliably?

well since no one posted yet and I need to even out my negative org CHI I will tell you what I know.

ok for starters I know the tip of the Ice berg but thats better than nothing. right?

your EGT's in most case is a direct coraltion of what your running in terms of AF. thats why most of the cheap bastards will use an egt as opposed to a wideband. cheap but effective.

now to your problem if your running a high EGT that means that your running lean (I belive)

I checked your REG and it says that your running the gm SC. are you using the safc along with the flash? if you arent then simply turn up the fuel.

what are your AFs if you dont know and your only using an EGT you might want to be worried more about det. then piston cracking.


"boobs now with Riboflabin"

Ya, most likely you are running lean up top. If you can, add more fuel up top in ur rpm range. If you can't....try alky injection.


1988 Pontiac Fiero, engine transplant underway.
2004 ECOtec, built and boosted

Any other solutions or is that about it?

Bingo, too lean. Let me guess, supercharged and running stock injectors and fuel pump still? The injectors probably go full duty cycle by around 4500 rpm under boost and can't keep up. Good way to cook your engine.

You need to richen up the mixture. Alky injection will help to a point, but to be safe I'd say get larger injectors and a bigger fuel pump, and then tune the car. You can't just slap a supercharger on the car w/ everything else being stock and not expect to run lean, I don't care how many guys on here are doing it.


Scott
2002 Audi S4, black
1996 Z24 auto, red

Scott Long wrote:Bingo, too lean. Let me guess, supercharged and running stock injectors and fuel pump still? The injectors probably go full duty cycle by around 4500 rpm under boost and can't keep up. Good way to cook your engine.

You need to richen up the mixture. Alky injection will help to a point, but to be safe I'd say get larger injectors and a bigger fuel pump, and then tune the car. You can't just slap a supercharger on the car w/ everything else being stock and not expect to run lean, I don't care how many guys on here are doing it.

....that's why GM gives you a lot of the @!#$ you need, duh.

Ok, I am not familiar with the kit because I have a 96. No need to get smart with me, I was trying to help. Blow your @!#$ up, see if I give a @!#$.


Scott
2002 Audi S4, black
1996 Z24 auto, red

With an attitude like that I doubt anyone here is going to waste their time to help you. You didn't have to get smart with me. I've probably forgotten more about performance engines than you even know.

By asking this question in the first place you've proved my point.

Now, I'm not trying to start @!#$ with you so don't take it that way. Just saying I don't appreciate you belittling me because I don't have the kit on my car.

So figure out how to richen up the mixture and your egt's will go down.

Have a nice day.


Scott
2002 Audi S4, black
1996 Z24 auto, red

The way I've seen all the other post you made Scott, You're the smart ass. You have bad info in almost all your post so please, use the noob section for a few more months then come back.



Gilles
2.3 Ho

If i was you i'd prob in an inline pump and up the fuel, you have the HO injectors so thats enough.....Now that being said...i do remember being told that EGT's can be deceiving...you maybe running too rich and heat the exhaust up...i'd try to find a dyno with a wideband and give a few runs, tune in your air/fuel and be done with it...

I appologize if I offended anyone. Not my intention. I was just trying to give you some help. I drive a supercharged car ever day of the week. I also have Z24, am new to 4-cyl cavaliers (somewhat but I've had mine for 3 years) although I'm not new to engines, or buiding engines. I've built many small blocks, a couple of V6's that were forced induction, and I'm building a big block right now. The 4-cyl is the least of my worries. Its the slowest thing I own.


Scott
2002 Audi S4, black
1996 Z24 auto, red

i helped put that s/c on your car when hanzenrider had it. you car is a 99 so you dont have the gm s/c reflash or map sensor so you just are adding a little bit of fuel and thinking everything is OK. which it aint. You are doing nothing for fuel adjustments when your car sees boost( what a FMU does).

first thing is first, ditch them HO injectors and put the stock ones back in.
RUN a cartech FMU and upgrade the fuel pump.
i have been through that same set up you have and my spark plugs were white and had a little bit of metal dust on them from detonation .
i added a cartech FMU, and put the stock injectors back in and got a new fuel pump and my plugs looked awesome.!.

Water injection too will help you out also (search in the boosted forum).

or you can run some bigger injectors(320cc) , turn down your Idle fuel pressure and adjust the rest with the AFC on a dyno. that might work too.

( i am suprised that car didnt blow up allready with that current fuel set up).

Team GREEN

opps, i mean a 98z24 with a 99 computer flash.

Team GREEN

when i talked with jason sunday , he mentioned you helping out alot jake


also i know jason didnt really beat on the car , and im sure the car ran fine for the way he drove it



and 95GtFire is correct , the egt's can be very decptive

also egt is the old school way of knowing what is going on , and it is a lost art

you have to know what the plugs look like , based on the egt readings , and know what happens when you go 1 way or the other , and to the extreme of either side


best anyone can tell you is get a wide band o2 , and then judge what the car needs from there

JuggaloZeke wrote:What are some ways one could go about lowering their Exhaust Gas Temperatures? My EGT's during normal driving normally hover around the 1200 degree mark and under heavy acceleration, if only for one gear, even, can reach upwards of 1500 degrees. I understand that at 1500 degrees it's very possible that one could crack a piston and I can't even wind out a single gear without getting close or exceeding that temperature.

Once again, what are some way one could lower EGT's reliably?

1500 F is normal.


sig not found

Way to lower EGTs:

More fuel (lose power)

More timing advance (possible detonation)


sig not found

Scott Long wrote:Now, I'm not trying to start @!#$ with you so don't take it that way. Just saying I don't appreciate you belittling me because I don't have the kit on my car.

Belittling you? You're the smart ass with comments like "You can't just slap a supercharger on the car w/ everything else being stock and not expect to run lean, I don't care how many guys on here are doing it."

Jake wrote:i helped put that s/c on your car when hanzenrider had it. you car is a 99 so you dont have the gm s/c reflash or map sensor so you just are adding a little bit of fuel and thinking everything is OK. which it aint. You are doing nothing for fuel adjustments when your car sees boost( what a FMU does).

Hey, I ain't doin' nothing! I'm just trying to figure out how to lower the EGTs with what I currently have.

Jake wrote:first thing is first, ditch them HO injectors and put the stock ones back in.
RUN a cartech FMU and upgrade the fuel pump.
i have been through that same set up you have and my spark plugs were white and had a little bit of metal dust on them from detonation .
i added a cartech FMU, and put the stock injectors back in and got a new fuel pump and my plugs looked awesome.!.

I don't have the stock injectors because Jason had never given them to me when I bought the car. He gave me lots of other things but not the stock injectors.

Jake wrote:Water injection too will help you out also (search in the boosted forum).

Was already planning on it, but thanks.

Jake wrote:or you can run some bigger injectors(320cc) , turn down your Idle fuel pressure and adjust the rest with the AFC on a dyno. that might work too.

The only problem with the S-AFC II is that it's based off of RPM rather than boost level, and the fact that it doesn't read RPMs correctly leaves me with only one viable option, the throttle percentage adjusments.

Jake wrote:( i am suprised that car didnt blow up allready with that current fuel set up).

You really think it could be that bad?

[quote=97cavie24ls(JDM&00s/c sedans™)]when i talked with jason sunday , he mentioned you helping out alot jake

also i know jason didnt really beat on the car , and im sure the car ran fine for the way he drove it

and 95GtFire is correct , the egt's can be very decptive

also egt is the old school way of knowing what is going on , and it is a lost art

you have to know what the plugs look like , based on the egt readings , and know what happens when you go 1 way or the other , and to the extreme of either side

best anyone can tell you is get a wide band o2 , and then judge what the car needs from thereDon't get me wrong, I don't beat on it either. Just driving home every night at 12:30AM on empty roads I get the urge to let 'er loose once in a while. Other than that I don't even go into boost much because I know it needs tuned badly but I haven't had the money which has changed, my new job is actually making me money so I can afford to get the parts I need to properly tune the car.

And I am planning on getting a Wideband. I actually have a wideband AEM sensor sitting right next to me but since AutoMeter is going to be releasing their wideband in April and it will actually match every other gauge in the car I was planning on waiting... that AEM gauge is hideous. I was thinking about looking for an inexpensive ($150 or less) gauge to just give me the information I am looking for for the time being and I am very interested in learning more about the MegaSquirt I keep hearing so much about.

Jake, funny thing is that you tell him to ditch the Ho injectors(with are 32lbs/hr) and replace them with 320cc ???? If he were to run an FMU, I can understand because the Ho injectors won't support more than 60psi of pressure but they deliver enough fuel to keep the engine alive and not destroy it but are not the best solution.



Gilles
2.3 Ho

All I was trying to say was that when GM originally chose the injectors for this engine I'm sure they had no intention of supercharging this engine. I'm not sure the conversion of 320cc to lb/hr rating and I'm too lazy to look it up right now. But I'll tell you this, if it is possible for them to support any kind of boost they should be able to raise at one psi of fuel pressure per 1 psi of boost. So if you are running 6 pounds of boost and your fuel pressure at idle is say 40 psi then your injectors need to be able to supply the engine with 46 psi of fuel pressure and be able to do it continuously. Not just a peak or a spike for a few seconds and then bleed off. Thats why I recommended larger injectors and a pump capable of supplying the higher pressure.

I am not sure the rating on the pump from the factory but lets also assume it wasn't designed for a boosted application. I don't know your car or what the previous owner did to it other than you say it has HO injectors which I gather are rated around 32 lb/hr. Do you have a fuel pressure gauge to make sure you are getting the proper pressure? An air/fuel gauge and a fuel pressue gauge along with your EGT gauge will give you a better handle on whats going on. Also checking your plugs like someone else mentioned is a great way to see whats going on in the combustion chambers. Like I said the best way (other than checking plugs after each run which is only viable option on a race car) is the wideband O2 sensor. I'm glad you got one, but it really isn't helping you if its not installed. I can understand wanting the guage to match the rest though, but you could mount it hidden say in the glove box or console that way it doesn't stick out like a sore thumb.

I think that when adding larger injectors you're going to need the computer tuned. I've done injector upgrades in several cars and we have had to retune them all or get a new sample tube for the mass air flow sensor to fool the computer into working properly with the new injectors. I don't see a MAF on my Z24 so I guess the best way would be to have the PCM tuned.

The reason many people probably say the HO injectors don't work well is because the computer isn't being retuned and you can't tube a MAF sensor since these cars don't have one.

On my other car I am running an M90 Eaton supercharger with a 2.85" pulley. I have an air to air intercooler and 30 lb/hr. injectors. I also upgraded the fuel pump to a walbro 190 lph pump. I didn't have to tune the computer for the bigger pump. I just noticed at higher rpms the fuel pressure would kind of drop off because the stock pump couldn't keep up. The injectors are doing ok for my power level. I run about 13 psi boost and everything seems to be ok. I put some plugs in my car that are 2 heat ranges colder. I did that only in anticipation of the nitrous kit I will be installing soon. Also when supercharging to see the maximum gains you should also have the tuner adjust the spark advance. It helps a lot of your engine has a knock sensor that can retard the timing if it hears the engine knock, but from what I've seen we don't have knock sensors on the LD9 motors.

I don't know what changes GM made to the reflashed PCM but I bet it compensates for larger injectors, spark advance (timing), and the fuel map. Running it without the reflashed pcm or a custom dyno tune specific to your car is just asking for trouble. Thats all I was trying to say in my first post. I appologize again if you thought I was being a smart ass. But what I said was a fact, you cannot just slap it on a stock engine and think its gonna last forever without problems untuned and with a fuel system inadequate of supplying the proper pressure. The reason I said I don't care how many guys may be doing it, is because I don't know personally how many people just slap it on and how many go about doing it the right way and making sure everything is up to par.

You said GM includes it all in the kit but yet your car isn't even properly set up. Good luck, check your plugs and see what they look like. That will be a little more accurate than the egt.


Scott
2002 Audi S4, black
1996 Z24 auto, red

This is directed towards Scott:

just to give you some back ground on the J-body 4 bangers and mods out there for us. Yes the GM supercharger kit has all hardware to mount the kit and a reflash to the ECU. Yes this reflash changins timing, and allows the ECU to read the 2 bar map sensor that comes with the kit (stock is a 1 bar). Also changes fuel maps as well. The biggest thing this reflash does is the mpa sensor, with out the ECU reading boost you have no way of increasing fuel under boost ( Unless you do a FMU). This reflash is only for 2000+ cars, or at least 2000+ ECU's. If you do not have a 2000+ car, or did not swap in a 2000+ wiring and ECU then you can not get this reflash. Which in turns means you have to figure out a way to increase fuel under boost. There realy is not other optons for stock computer programing for the J-body's at this time. RSM say they reflash the ECU for the supercharger kits as well, but I do not think (could be wrong) that they will reflash the ECU for other kits. JBP performance says they can custom tune the ECU as well, but yet we have not heard from one person who has tried it, so of course people do not know if they can really do it. So that leaves us with either adding FMU's, AFPR's, and SAFC's and tuning the best we can, or spending big money on standalone's like TECIII's, and others like it. There is alos the Emange, Megasquirt as well and people have had good success with those as well. I would agree that retuning the ECU for bigger injectors is the best route, but not really a option for most at this time. There is a company HPTuners that was working on software to allow us to tune the stock ECU like it was a standalone (which would be great!!!), but nothing has come of that. We do not have a LS1 edit, or other programs like it for tuning.

Now to JuggaloZeke:

The SAFC reads RPM's just fine if hooked up correctly. Yes you can't tune on boost levels, but if you use a FMU to get fuel under boost and get the FMU dailed in, you can then use the SAFC to fine tune where needed ( like idle for bigger injectors, and other areas in the RPM range).
Have you pulled your plugs to see what they lok like? I relaize you might not dog the car, but you could be running lean just under normal driving. Do we really think it could lead to blowing up the motor??? Yes
So you have the AEM wideband kit?? You need to hook it up. I understand you want the Autometer one, but use what you have then sell it after you got want you want. This could really help you see where you are at, and save your motor.

scott , the injectors gm supplies with the kit and the HO's are very close to the same size


with out a wide band its hard to tell what is right and wrong while he is driving


checking the plugs will give you a indication of how the fuel is , but isnt very accurate , unless you make a full throttle pass shut the car off and look at them

because they will change from the high rpm pass to driving to idling , but it will help out


i dont think the 1500 egt is that abnormal , but its only part of the whole picture that needs to get looked at

and with out the ability to tweak the pcm , we have very limited options

Ok, so he is in the same boat I am in when looking at ways to get more from the LD9. I have a 96 and for a short time was thinking about getting the GM supercharger except for the fact that I can't tune for it. I understand that much. Which got me looking into stand alone fmu's. For the price of all that I will have an L67 in my car making a lot more power and probably still have less into it than it would cost to buy the supercharger kit and an fmu and dyno tune time, plus learning how to adjust it all etc..

Maybe he should just get a 2000 pcm and swap in the harness and then do the reflash. A lot less money, maybe more hassle to remove and replace the harness, but a lot cheaper and easier to program.

That's exactly why I'm going L67, 240 hp stock w/ a stock pcm. Thats probably more than the LD9 at 6 psi. There are more options for more power, the pcm can be tuned, and parts are readily available. Not to mention that kind of power in a JBody car is gonna rock. And my engine won't be stock. It'll be getting a cam, ported heads, valve springs, pulley, tb upgrade, custom intake and exhaust, custom pcm tune, nitrous.... I am going to put an LSD in the 4t65e tranny as well.

Anyhow reading the plugs is a good way to look at the engine no matter what kind of driving you are doing. You can tell alot just by looking at the plugs. If he does mostly easy driving low boost and his plugs are white as a ghost, he will know something.


Scott
2002 Audi S4, black
1996 Z24 auto, red

Scott Long wrote:Ok, so he is in the same boat I am in when looking at ways to get more from the LD9. I have a 96 and for a short time was thinking about getting the GM supercharger except for the fact that I can't tune for it. I understand that much. Which got me looking into stand alone fmu's. For the price of all that I will have an L67 in my car making a lot more power and probably still have less into it than it would cost to buy the supercharger kit and an fmu and dyno tune time, plus learning how to adjust it all etc..

Maybe he should just get a 2000 pcm and swap in the harness and then do the reflash. A lot less money, maybe more hassle to remove and replace the harness, but a lot cheaper and easier to program.

That's exactly why I'm going L67, 240 hp stock w/ a stock pcm. Thats probably more than the LD9 at 6 psi. There are more options for more power, the pcm can be tuned, and parts are readily available. Not to mention that kind of power in a JBody car is gonna rock. And my engine won't be stock. It'll be getting a cam, ported heads, valve springs, pulley, tb upgrade, custom intake and exhaust, custom pcm tune, nitrous.... I am going to put an LSD in the 4t65e tranny as well.

Anyhow reading the plugs is a good way to look at the engine no matter what kind of driving you are doing. You can tell alot just by looking at the plugs. If he does mostly easy driving low boost and his plugs are white as a ghost, he will know something.

I have to disagree with you on the price to put a L67 adnd 240hp??? is cheaper than supercharging a LD9 and tuning it. Many people are doing it on pre 2000 cars and doing well. Another thing I forgot to mention about the GM charger reflash (which is something I do not like) is it pulls alot of timing. Of course this is done to allow a warranty, but also robbing power. That is why I would rather boost a pre 2000 car and set it up the way I want. Of course using the Gm program as a starting point (if you can tune the ECU), to get you where you want to be.

I didn't know the GM reflash pulled timing, like you said thats probably for warranty purpose. Thats good to know that there is a little more power to be had if you get it retuned after that.

I still think he should swap to the newer pcm and harness and use the reflash as a starting point. Unless he wants to buy a stand alone.


Scott
2002 Audi S4, black
1996 Z24 auto, red

Quick Update: I went ahead and got the wideband installed and at WOT it reads between 12 and 13.