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Allessence,

That sounds more like souped up ricer, not that thats bad just different. Just goes to prove where our burrble comes from,(manifoled).

Oh, and after floging your turbo, you didn't wait one minut before shutting it off.:nono; :cheesy: hehe.
 

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spg1 said:
Allessence,

Oh, and after floging your turbo, you didn't wait one minut before shutting it off.:nono; :cheesy: hehe.
I barely even got the turbo to warm up. Plus I'm using Mobil 1 15w-50. The best [email protected]#$% stuff on earth. Just kidding. I'm do for a turbo upgrade at some point. A GT28RS seems to be the one I'm going to be looking into. I want something that can boost 30lbs pretty easily. I looked in VNT turbos but nothing out there seems to fit the bill at this point.

The turbo housing is cracked inside. The crack is large enough that it actually hits the turbine ever so slightly, and besides that the compresssor wheel has some damage.

My air filter failed twice. The epoxy K&N used came undone so I JB welded it. But, it seems epoxy, RTV, Silicone, any of the automotive sealants just don't work for me. I know a mechanic who just slops stuff together and nothing ever leaks.

I clean and prep and clean again, make sure everything is dry and clean, new gaskets, seals you name it. They leak. Go figure.
Any sealed anything, and transmissions are my down fall. Oh, well. I'll keep trying if someone let's me.


Anyhow, when the filter let go it's on the inside and you can't see it. I must have picked up some gunk because the compressor blades have chipping in them.
 

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How do you know that your turbo need to be replaced other than knowing the crack is there, can you hear anything defferent?
 

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If you take the compressor side pipe off and turn the compressor wheel if you hear or feel the wheel sticking. I don't mean bearing friction. I mean as it's being turned you can feel the dut, dut, dut of the turbine wheel hitting the hump formed by the crack.


Also any chips in the compressor wheel will lower it's effecientcy.

I don't think with the car running you can hear a difference unless it's really bad and then it's usually the bearings or the turbo is out of balance.
 

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Discussion Starter #65 (Edited)
My boss found the data in the program I left running over night as it runs thousands of audio simulation which takes hours to process, anyway he was not happy with me but after I explained what I was doing to the exhaust system and he showed some interest at this point.

I told him I was trying to make the exhaust ports flow better so more air could escape, he said "Well you want the ports to go sonic then" :eek:what?

I didn't even pretend to know what he was talking about this time like a normally do, he basically said I missed out lots of parameters but 3 important variables in the program for the results to be meaningful in the real world were.

1.Sonic pulse.
2.Thermal Pulse.
3 Gas velocity/expansion rate
4.System input

The sonic pulse is the fastest wave in the exhaust system and its behavior is related but different from the thermal pulse and gas velocity, ie it can take corners without a reduction in speed and return to the valve seat faster then the thermal or gas velocity, this is why exhaust systems are long, so the sonic pulse comes back to a closed valve and not an open one,
OK I get it, thats what I hear and I'm trying to tune.

The thermal pulse is a wave in the system, the 4 piston chamber may have a 2 liter total capacity but the expanding or vented exhaust gas has more volume, what goes in comes out fatter, I guess the universe really is expanding, lol, ok I get that as well.

The velocity is critical for a fast turbo recycling or spool I was told, and to maximize the velocity I should make a delaval shape exhaust port, ok I didn't get that so I Googled it for 3 hours.

It turns out I had already made it by accident, its an hour glass figure basically, narrowing inner mouth and wider side walls, thats how the gas jets were narrow shooting out my head, a total fluke!

I was told to make them narrower further back but I'm not doing any more welding and I have the flu again, so no thanks.

I removed all the imperfections from the cast manifold and there were a lot to my surprise, its made of chrome alloy so it really did eat my grinding stones and took 7 hours, I did not mirror finish the manifold as the waters wetting and boundary affect would overrule any benefit of polishing it seems.





I took it to work this morning dipped in acid and then spray in one layer of ceramic paint which is good for 1200 degrees but I plan on totally caking and baking the inside and outside again when I install the 3 inch pipe work in open mouth plate.

I really don't think the cast manifold is slowing the engine down, I measured its internal volume using sand and its a touch over 2.3 liters, coincidence?

I did sample your exhaust and Jennifer and it has very defined sound pressure wave, what size is your exhaust system?

This is your idle, it very, very consistent indeed.






This graph above was your acceleration phase, it has lots of amplitude which means high pressure and once again is very consistent, it looks like the sound energy is very even across your rpm range.

Your camera was using a AGC with adjust the signal to the microphone so dont be surprised that its not off the chart in terms of db.

I have no idea what the rasping sound was to be honest, it could have been a wind noise effect or just the vortexs from your exhaust tip

Were is your peak power on a dyno graph 3200rpms?

I have a newer mad idea for the manifold but I need to see if its even realistic first, you will like this being a nut.
 

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ShadowWorks said:
My boss found the data in the program I left running over night as it runs thousands of audio simulation which takes hours to process, anyway he was not happy with me but after I explained what I was doing to the exhaust system and he showed some interest at this point.

That is fantastic. Your boss showing some interest. Sounds like a person whom has vast knowledge and likes a treasure hunt.

I told him I was trying to make the exhaust ports flow better so more air could escape, he said "Well you want the ports to go sonic then" :eek:what?

I didn't even pretend to know what he was talking about this time like a normally do, he basically said I missed out lots of parameters but 3 important variables in the program for the results to be meaningful in the real world were.

1.Sonic pulse. The sonic pulse is the supersonic pre explosive sound wave that travels just as the explosive energy is released. It's like a prewave and has the highest energy of all the waves. It is also the wave used in tuning exhausts especially in 2 strokes but also in 4 strokes. The pulse can and does expand and contract to the inside diameter of the tube it is traveling in without loosing my of it's energy. It is also a reflective wave. It will bounce off objects in the exhaust system. If you add a plate to the middle of the exhaust head it will reflect the wave back and a person can change the Valve to valve timing as well as port to port. Basically out and back.

2.Thermal Pulse. Thermal pulse is the pulse that is generated when the explosive gases reach max Thermal force/expansion for the given volume of container and is what makes explosives work so to speak. *1Also the gases around heat/flame/explosive energy become super heated in a matter of Mseconds. this energy also creates positive and negitive pressure areas and is related to both thermal pulse and gas velocity. The thermal pulse also only creates a return pulse (low pressure area) but it's minimal and is short lived and is usally at the beginning of the flame kernal.

3 Gas velocity/expansion rate The gas velocity can be low but the Sonic pulse can be huge. The P&P of the head will have a very large influence on these two as well as the manifold. *2, On a tube header if you make a header. Start with medium size pipe and either work up or down if not gettng the results you want. In the pictures you took, the exhaust kernal was coming out not only with an arrow point flame front but also it pulses forwards with front narrow to wider to narrow behind the main flame kernal. (read *1 again)
4.System input

The sonic pulse is the fastest wave in the exhaust system and its behavior is related but different from the thermal pulse and gas velocity, ie it can take corners without a reduction in speed and return to the valve seat faster then the thermal or gas velocity, this is why exhaust systems are long, so the sonic pulse comes back to a closed valve and not an open one,
OK I get it, thats what I hear and I'm trying to tune.

The thermal pulse is a wave in the system, the 4 piston chamber may have a 2 liter total capacity but the expanding or vented exhaust gas has more volume, what goes in comes out fatter, I guess the universe really is expanding, lol, ok I get that as well.

The thermal pulse will only last for as long as the heat remains at a steady state. As the temp falls so does the thermal pulse.Also the longer the air around the pulse get's more contact it is also expanding and creating a low and high pressure area in front of it if exposed to ambient air pressure. If you can keep the heat in it, it will do more work.

The velocity is critical for a fast turbo recycling or spool I was told, and to maximize the velocity I should make a delaval shape exhaust port, *2 3rd bold paragraph. On a turbo charged car we use the Sonic pulses to generate the largest hit to the turbine. The turbine is driven by, Sonic pulse, stays the same pretty much, Thermal pulse gets longer/ thinner as it goes into the turbine housing but with much less force than the Sonic pulse. and then lastly exhaust velocity to a lesser or greater extent. depending on back pressure within the exhaust manifold. The sonic pulse isn't influence as much by back pressure as much as velocity is.


I removed all the imperfections from the cast manifold and there were a lot to my surprise, its made of chrome alloy so it really did eat my grinding stones and took 7 hours, I did not mirror finish the manifold as the waters wetting and boundary affect would overrule any benefit of polishing it seems.

A solid clear polish will keep the Sonic wave moving at a smoother pace than an area with roughness. The idea about water wetters, boundry effect has to due with fluid dynamics and eddy effects. As air/water passes over an object the area in contact grabs the air/water and creates a shear layer. This is where the outside layer starts to curl around on itself because of the friction generated. This has to do with gas velocity, more than sonic pulse. The more pressure fed thru the tube the greater the shear and the consequence of the eddy getting larger and as some point will start to interfer with flow toward the center of the tube. This speed is usually at the speed of sound. The sonic wave /pulse can actully clean the eddy's off the sides(not exactly) and create a smoother flow pattern. So, if the tube is absolutely smooth and once put into use will do 2 things to remove problems which can hurt performance. It will help to keep carbon from building up on the inside of the manifold and it will keep the pulse moving along instead of getting caught on reflective ripples. Also as the manifold gets used it wil get some carbon build up and create the small eddy/slip effect I beilieve you after.

The inside of exhaust tubes, 2 stroke expansion pipes must be kept burr, ding, and weld puddle free.

This is the kind of crap my head is full of. I should have gone to school to become and engineer.

I did sample your exhaust and Jennifer and it has very defined sound pressure wave, what size is your exhaust system? Thanks for the sampling. very neat. Will you be keeping these for future experiments?

This is your idle, it very, very consistent indeed.






This graph above was your acceleration phase, it has lots of amplitude which means high pressure and once again is very consistent, it looks like the sound energy is very even across your rpm range.

Is the highest point the initial firing phase and then the rest the end pulses? going form left to right? Not forwards to backwards.

Your camera was using a AGC with adjust the signal to the microphone so dont be surprised that its not off the chart in terms of db.

I have no idea what the rasping sound was to be honest, it could have been a wind noise effect or just the vortexs from your exhaust tip

Were is your peak power on a dyno graph 3200rpms? 4000rpms is max power and is where the exhaust sound changes into the air leaking sound.

I have a newer mad idea for the manifold but I need to see if its even realistic first, you will like this being a nut.
So, what's the next idea? I'm very curious. Maybe this should be patentened.

J
 

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I was just comparing your exhaust sample to mine. And there is a space in both samples. Your sample is 0ms to 6000ms and if I am reading it right shows a larger gap than a smaller gap between 2000ms and 3000ms and again at 3500ms to 4000ms. Correct?

In my sample was 1500ms and 2800ms. Correct?


I am really enjoying the exchange of info. I find the sound info very fascinating. Thanks a lot. J
 

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Sha,
This Delaval shape that you are talking about, is it more of a funnel shape or a velocity stack shape?

When you say that you did some welding, did you reweld or build up arias that you ground down in porting?

The rasping sound or (thrashing sound) that you heard from Allessence video sounds like mine does that I have been trying to explain (where did my spooling sound go). I can't hear the spooling wherl or high pitch sound anymore and in reading what Allessence said about his turbo that it has a crack in it may be what I have and what you hear. What do you think?
 

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spg1 said:
Allessence said about his turbo that it has a crack in it may be what I have and what you hear. What do you think?
Hi spg1, He is really a she,Or I should say Allesence is a female, Jennifer is my name. I had thought my sign on name would have given the hint, but I guess I was wrong.

I guess if I'm going to be hanging out in this male dominated SAAB world I'm going to have to change my sign on name/handle to something that reflects my female nature for those whom don't get it, shewhospeakssaab or maybe girlsaabpower, or maybe jenniferisnotahe, or how about girlwhogoesfast I actually like this one.

So, just because I love SAABs and have some knowledge does not dictate I am a male nor want to be male.

I am simply a girl who loves SAAB's and likes to drive them fast. Knowledge is power female or male and I have had many bad experiences with Males who think they are great mechanics who think they have it going on, only to end up paying their outrageous bills and end up with un-fixed problems when I told them what was wrong and just to fix that. :nono;

So, I read a lot and did the research nessasary to be or do the work myself. Thank you very much.

GO Girl power!!!!! :p

Oh, by the way, I am quite forwards, and bossy. :roll: Jennifer
 

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Discussion Starter #70
I know your a woman;), my mums a woman half dragon:lol:

Most of the smartest people I know are women, some of the toughest people I know are women, I agree its a car dominated world only because women muilti task are busy doing real stuff and men just sit about getting fat and talking about cars, have you seen that show, King of the Hill?

I spent to much time working on my car and not enough time working on my own mind body balance, maybe cars are simpler to work on and the results are instant, working on our own spiritual and physical body or soul, there are just no after market parts that can be bolted on:lol:

Anyway I think my mad idea maybe unworkables only because of my budget and tooling availability.

I though I could add a fifth fuel injector on my manifold and turn it into an afterburner:cheesy: sounds mad I know but hear me out.

The EGR is perfectly place for an injector at the end of the manifold branches, the thermal pulses could ignite the extra fuel making a huge shock wave and thermal pulse that would smash the turbo giving instant boost, what do you think? I know I'm mad.

I am not sure how much oxygen is in the exhaust gas but I could in theory take a small diameter pipe off the turbos compressor side and use this to flush the manifold with air around the injected fuel?

I thought to test my theory I would use a surgical need with 5cc of fuel and just squirt it in.

Don't all laugh at once;)
 

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OH NO!! OOOOOOPS
Don't go and change your name on my acount, although girlwhogoesfast is a good name. I saw your name and thought ...........Naa that can't be, this person is some major tech guy, ya know, like you said, you don't see many women here on the site. To call you a "he" would be safe in some regard, for a woman and then say (OH NO!! OOOOOOOOPS) it was a mistake:cheesy:. But to call a guy a she isn't good at all, I mean you know there was a guy call "Sue" in a song so why not a guy called "Jennifer" Well maybe not:roll: :lol: My have I put my foot in my mouth or what!;oops:

Well I think your cool and Im glad your on our side, "The Saab" side, that is :cool: I Like a woman that Saabs from time to time:cheesy: Did I just stick my foot in it again? OOPs, Hehe

Dennis
 

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The EGR is perfectly place for an injector at the end of the manifold branches, the thermal pulses could ignite the extra fuel making a huge shock wave and thermal pulse that would smash the turbo giving instant boost, what do you think? I know I'm mad.

I am not sure how much oxygen is in the exhaust gas but I could in theory take a small diameter pipe off the turbos compressor side and use this to flush the manifold with air around the injected fuel?

I thought to test my theory I would use a surgical need with 5cc of fuel and just squirt it in.

Don't all laugh at once;)
You need a recirc dump valve which is connected to the ex man, so when the throttle plate shuts the excess boost is dumped through the turbine.
 

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You should read up on anti lag systems, they achieve the same thing by retarding the timing a lot, and dumping loads of fuel in. But I don't think you want to rebuilding/replacing your turbo every few hundred miles :)

<edit>
Did some more googling..
This describes the old "bang bang" anti lag system.
http://www.rallycars.com/Cars/bangbang.html

Estimated lifetime on a road car, 50-100km.

But the modern anti lag system is not too far away from what you were saying, air is fed from the compressor to the exhaust manifold. But it seems that another injector is not needed, the mixture is kept rich, and just ignites in the manifold..
http://en.wikipedia.org/wiki/Anti-Lag_System
 

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There is another option. VNT turbos. I have been looking into these but am having a hard time finding a suitable unit for my purposes.


Turns out the GT28RS or any of the ball bearing turbos are supposed to be dramatically better than the journal type for spool up, and with the right combination will give almost instantanious boost response.

With the VNT turbo you can run 5lbs of boost at idle in ideal situations. The problem becomes sufficent air flow at higher boost pressures and RPM;s also trying to find any info is just about impossible.

With intense turbo driving the idea is really not to lift off the throttle. Left foot brake or Heel/toe brake gas for down shifts. While keeping the rpms up.

For boost run on they also used a rev limiter that skipped cylinders. This added the necsasary fuel for manifold burn. How it worked is just to keep the car floored between gear shifts. the rev limiter would keep the rev's steady and as soon as the next gear was engaged the car would switch back to basic run mode. With a cat in the car the cat last's about 50-100miles with that kind of driving.

Over here in MA we have cats on any car produced after 1983 (84my) and are driven on the street.
 

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Discussion Starter #75 (Edited)
philb said:
You should read up on anti lag systems
Thanks man I just did after you posted the links, I thought I was just being silly:lol: So I don't need fuel, I just need air, this should be very easy to do?

I never even really thought of this idea, it was my boss, I showed him the manifold and he said whats that port for? a lambda or some kind of turbo assist, I said no its for the EGR, he then should I could use the port to ignite the thermal pulse and give instant spool, that all he said and walked away, I thought I needed fuel but the exhaust gases are fuel rich as the injectors do not reduce their flow instantly.

Our cast log manifold are made of hardened steel so I'm not worried about melting it, that the big down side apparently, the temperatures rise above 1200 degrees in these turbo anti lag system, I would only use a mild ALS not a full pressure one, if I can maintain 10Psi at idle I would be very happy, can you imagine what a hard time the dump valve would have:lol:

Left foot braking is a skill I just don't have and I don't want to risk over heating my road pads, are the VNT turbos not like $1500 plus?

This Anti lag mod would not cost more than $100 as a DIY effort.
 

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Over here in MA we have cats on any car produced after 1983 (84my) and are driven on the street.
A mechanic rescently suggested introducing the ceramic core of my cat to a broom handle, he recond the testers would'nt be able to tell the difference.

Sha, rather than using a stock recirc. you need an external WG, you just swap the nipple to the back of the diafram so it opens when a vacuum is applied to it, stick it on your inlet with it venting to the exhaust manifold.
 

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Not injecting extra fuel didn't make much sense to me, you'd be running very rich.

Did more googling,

Rally cars use a different way of introducing petrol into the exhaust manifold. There are separate injectors that introduce fuel directly into the exhaust manifold. Some of this mixture will continue burning in the turbine and down the exhaust system, resulting in the flames and explosions you hear coming out of the exhaust muffler.
http://paultan.org/archives/2006/06/28/what-is-an-anti-lag-or-misfiring-system/

But, I don't think its a great idea. How much lag does the car really have? With the mitsu turbo, and a dump valve, I get very little lag. When I change from 3rd to 4th, its back on boost in an instant. You have the same turbo, the only thing I can think of thats giving you more lag is the FMIC.
As for left foot braking - its a skill well worth developing, its used more to adjust the handling of the car, theres not much need to use it to reduce boost, though I have tried this once.
Brake pads are cheaper, and much easier to change than turbos. I'm afraid your argument doesn't work from an economic point of view.. but it would be cool.
 

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philb said:
As for left foot braking - its a skill well worth developing, its used more to adjust the handling of the car, theres not much need to use it to reduce boost, though I have tried this once.
It's not to reduce boost. It's to keep the engine rpms in a range that keeps boost avalible at an instant. The greater the load the more boost the turbo will produce. This is why if you are just idling the car and romp on the gas the boost doesn't really go anywhere once it reaches ambient.

When I switched from the log style manifold to the tube type my max boost dropped in accordance to the amount of free flow availible. If you boost in 1st or 2nd you will find the car boost is not quite as high as if you were in 4th or 5th gear with a load 3200rpms, full throttle going up a hill. You will find boost rises and continues until it detects knock or until the waste gate opens. My basic boost (wastegate) is set to 15lbs and 1st, 2nd doesn't even really get a chance to do anything. It redlines as soon as it has gas.

I'm going to have to get some video taken. Maybe today. More than likely not. One of my rad cooling fan's came apart. I'll see what I can do.

Shawdowworks, Do you have a time frame for when this car is going back together for a road test?
 

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Discussion Starter #79
Si said:
A mechanic rescently suggested introducing the ceramic core of my cat to a broom handle, he recond the testers would'nt be able to tell the difference.

Sha, rather than using a stock recirc. you need an external WG, you just swap the nipple to the back of the diafram so it opens when a vacuum is applied to it, stick it on your inlet with it venting to the exhaust manifold.
Si you can get a fake CAT;)

Thats another good way of pushing air into the manifold.

Phil my original plan was to have a fifth injector firing into the manifold, not the engine but its not needed it seems, the stress I'm talking about is the stress left foot braking puts on all the parts not just the pads.

I really don't drive fast enough around corners to give left foot breaking a chance, I only drive fast on when its safe to do so and on the motorways, now in a Go Kart thats a different story;)

My FMIC has 3 times the internal core volume, it has less lag then the stock IC because of the tank ends and my piping.

I have never seen or been in a car with the ALS but the theory is sound and its been used by rally drivers and those gits know about power mods and skillful driving.

Jennifer I currently have the Ebola flu virus:cry: everything sore and its been raining cats and dogs the weekend, I like performing one mod and test it rather than do 2 or 3 mods and not know what is doing what, I will let you know how it goes.
 
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