Is200 Kompressor
Is200 Kompressor
![[Image: LexuS-Copy.jpg]](http://i65.photobucket.com/albums/h204/Sparkystav/LexuS-Copy.jpg)
Read my thread here: The Evolution of my Turbo Lexus from NA-Supercharged-Twin Turbo-Massive Single
Please leave your comments.
Sparkystav
18-01-2024, 12:27 AM #61Is there any codes coming up? That would give a clue.
Read my thread here: The Evolution of my Turbo Lexus from NA-Supercharged-Twin Turbo-Massive Single
Please leave your comments.
Only thing so far is the TPS/TB buzzing like mad. The more I think about it, it seems like an air restriction/metering issue. Smells "fuelly", getting spark. Seems like only air it's not getting/restricting.
DannyStock
18-01-2024, 09:27 AM #62Bloke at work has got a code reader which he's lending me, will post the results of what that brings up when I get it plugged in.
Only thing so far is the TPS/TB buzzing like mad. The more I think about it, it seems like an air restriction/metering issue. Smells "fuelly", getting spark. Seems like only air it's not getting/restricting.
So good news, it's nothing too serious (right?).
But it's also nothing obvious.
This only leaves me thinking it's my diesel valve sticking under high temp/load...
Either way - POWER RUNS TOMORROW!!
Find out how much grunt I've gained (Y)
Wayne; Thanks for the offer, but i'm holding out for a set of coilovers. Got no issues with lowering springs, but I always find myself wanting the adjustability. Cheers all the same.
DannyStock
19-01-2024, 02:09 PM #64Plugged in OBD - No codes, no nothing.
So good news, it's nothing too serious (right?).
But it's also nothing obvious.
This only leaves me thinking it's my diesel valve sticking under high temp/load...
Either way - POWER RUNS TOMORROW!!
Find out how much grunt I've gained (Y)
Wayne; Thanks for the offer, but i'm holding out for a set of coilovers. Got no issues with lowering springs, but I always find myself wanting the adjustability. Cheers all the same.
176.9 BHP (flywheel)
147 LB/FT
(increase of 26.6bhp & 24.4lb/ft)
Stock /n/a was 150bhp @flywheels & 129lb/ft.
Running less boost than standard TTE seems an acceptable increase with that in mind.
Can't deny I'm a little disheartened though lol
DannyStock
20-01-2024, 06:51 AM #65POWER RUN RESULTS:
176.9 BHP (flywheel)
147 LB/FT
(increase of 26.6bhp & 24.4lb/ft)
Stock /n/a was 150bhp @flywheels & 129lb/ft.
Running less boost than standard TTE seems an acceptable increase with that in mind.
Can't deny I'm a little disheartened though lol
![[Image: IMAG0968.jpg]](http://s261.photobucket.com/user/CANNYDOE/media/IMAG0968.jpg.html)
![[Image: IMAG0969.jpg]](http://s261.photobucket.com/user/CANNYDOE/media/IMAG0969.jpg.html)
Interesting part here is the 6hp decrease in drivetrain drag.
Only thing here that has changed between the two runs is poly diff mounts - Nice.
DannyStock
20-01-2024, 07:48 AM #66
Interesting part here is the 6hp decrease in drivetrain drag.
Only thing here that has changed between the two runs is poly diff mounts - Nice.
Sent from my iPad using Tapatalk
Read my thread here: The Evolution of my Turbo Lexus from NA-Supercharged-Twin Turbo-Massive Single
Please leave your comments.
Sparkystav
20-01-2024, 01:39 PM #67What boost are you at?
Sent from my iPad using Tapatalk
Read my thread here: The Evolution of my Turbo Lexus from NA-Supercharged-Twin Turbo-Massive Single
Please leave your comments.
Boost gauge might be arriving soon, birthday dependent lol
DannyStock
20-01-2024, 01:47 PM #68Not the foggiest what its running.
Boost gauge might be arriving soon, birthday dependent lol
The throttle body is placed before the supercharger with an air to water intercooler after the charger. Air to water cooler is used because usually the charger is mounted directly on the intake manifold, so the air volume after the throttle body is kept to a minimum - this helps with engine response immensely. Using a remotely mounted supercharger with a throttle body before it and having long piping and air to air intercooler adds a very large volume of air after the throttle body - which introduces all kinds of engineering problems. That's why you rarely see this. Anyway, with the supercharger after the throttle body, it needs a bypass valve for when the throttle is closed, because the supercharger, being a positive displacement unit is pumping air constantly and when the throttle is closed, it quickly sucks out all the air at the inlet and starts to add massive parasitic loss to the engine. So a bypass valve is added, which is vacuum actuated off this very vacuum at the supercharger inlet - after it opens, it allows for the pressure before and after the charger (all after the throttle body) to equalize, essentially eliminating the parasitic loss of the charger at part throttle. That's why all bypass valves on the markets are vacuum actuated (many are actually integrated in the supercharger housings).
And this is where the TTE designed system comes in - the IS200 isn't very suitable for superchargers on the intake manifold, because the cost would be high to do so and also there's a convenient free space above the exhaust manifold. So they decided for a remote supercharger install, but that means that to do it properly, placing the throttle before the charger wasn't an option. So the other way to go was to use the charger as a turbo. And this is where we're at. But the option to just use a blowoff valve like on a turbo isn't OK, because the charger is spinning constantly and the roots design doesn't allow air to reverse its flow back through the charger (like turbos or centrifugal superchargers surging). Which means a high flow valve has to be added and has to be operated in sync with the charger operation - just like a bypass valve. But without a vacuum feed at the charger inlet the only vacuum feed can be the intake manifold - which isn't OK, because the vacuum there doesn't have a direct relation to the supercharger load with the throttle between the two. That's where the cable operation comes into play - with a cable connected directly to the throttle and operating the bypass valve with the correct ratio, you can have a fully synced system, where the supercharger never loads up unnecessarily and you essentially have a boost controller attached to your right foot - the more throttle you apply, the more boost you'll have. An ingenious solution, hats off to TTE engineers.
I've also written an extensive explanation why the vacuum bypass often causes issues, especially at higher boost levels. I've seen this too many times to count, so here goes:
The Mini Cooper vacuum bypass valve, used in most DIY supercharging applications for the Lexus IS200 introduces several problems:
- Unwanted acceleration (at part throttle the car may tend to accelerate on its own at full boost without additional throttle application)
- Bad throttle response (it's either ON or OFF, no middle ground, making the car tricky to drive and sometimes dangerous)
- Limp mode issue (when trying to feather the throttle and balance the boost the car often goes into limp mode and you have to stop, turn off the engine, wait a couple of seconds and start it again)
- Impossible to cruise at motorway speeds (the unwanted acceleration problem and limp mode problem)
- Traction control almost always triggers limp mode
After extensive tests, we found out that the problem is in the vacuum bypass valve and its relation to the throttle operation. In the genuine TTE kit there's a direct (almost linear) relation between the throttle operation and the bypass operation (closed throttle=open bypass and vice versa). This is done by mechanical cable.
With the vacuum bypass valve the end points of this relation are the same (closed throttle=open bypass and WOT=closed bypass), but the problem lies in between those 2 end points - the relation isn't linear.
The problem occurs at different throttle positions depending on the vacuum bypass valve spring strength but usually at about 30-35% throttle - say you're trying to keep a constant speed, which requires about 35% throttle and the following happens:
1. 35% throttle gives you about -0.2 bar vacuum in the intake manifold, which gives you the perfect amount of power to maintain your speed
2. At -0.2 bar the vacuum bypass valve starts closing;
3. With the partially closed bypass valve, the pressure in the intercooler and piping rises;
4. With the pressure before the throttle body raised, more air starts to go through the partially open throttle body (throughput = area x pressure);
5. With more air coming through the throttle body, the pressure in the inlet manifold rises;
6. Raised pressure in the inlet manifold means the bypass valve closes even more;
7.With the bypass valve closed even more, the pressure in the IC and piping rises even more;
8. This process continues exponentially until the bypass valve closes fully. Now the bypass valve is closed at 35% throttle (while on the cable operated bypass this should be at over 80% throttle).
9. With the bypass fully closed, the pressure in the IC and piping rises exponentially - the air has nowhere to go except through the small throttle opening;
10. With pressure before the throttle body rising, the pressure in the inlet manifold continues to rise.
11. The ECU has a failsafe threshold for the relation between TPS and MAP sensor readings, so at low TPS readings (partially closed throttle body) the MAP sensor should read no more than a certain amount of pressure (or vacuum, if we're taking atmospheric pressure as a reference). This is because in the event of inlet manifold mechanical failure (say we make a hole in the manifold, or disconnect a large vacuum line), the engine gets enough air to rev freely even if we don't apply the throttle. In this event, the ECU cuts fuel and ignition timing, so the engine doesn't overrev itself or unwanted acceleration doesn't occur. And at this exact moment at 35% throttle, the MAP sensor reads too high inlet manifold pressure, so this failsafe is triggered, also known as limp mode.
The way to avoid that is to have a bypass valve, which has direct and linear relation to the throttle body and not inlet manifold pressure. This is where this kit comes into play – it mimics the operation of the original TTE bypass valve to the fullest, so it eliminates all problems explained above in one go. A simple and elegant solution to a very annoying problem.
I hope I've been of some help...
OK mate, I'm the guy people talked about a few posts back, who designed a similar system to the TTE cable bypass. Let me try and say a few words of how supercharging systems are supposed to operate (and how 99% of roots superchargers are used):
The throttle body is placed before the supercharger with an air to water intercooler after the charger. Air to water cooler is used because usually the charger is mounted directly on the intake manifold, so the air volume after the throttle body is kept to a minimum - this helps with engine response immensely. Using a remotely mounted supercharger with a throttle body before it and having long piping and air to air intercooler adds a very large volume of air after the throttle body - which introduces all kinds of engineering problems. That's why you rarely see this. Anyway, with the supercharger after the throttle body, it needs a bypass valve for when the throttle is closed, because the supercharger, being a positive displacement unit is pumping air constantly and when the throttle is closed, it quickly sucks out all the air at the inlet and starts to add massive parasitic loss to the engine. So a bypass valve is added, which is vacuum actuated off this very vacuum at the supercharger inlet - after it opens, it allows for the pressure before and after the charger (all after the throttle body) to equalize, essentially eliminating the parasitic loss of the charger at part throttle. That's why all bypass valves on the markets are vacuum actuated (many are actually integrated in the supercharger housings).
And this is where the TTE designed system comes in - the IS200 isn't very suitable for superchargers on the intake manifold, because the cost would be high to do so and also there's a convenient free space above the exhaust manifold. So they decided for a remote supercharger install, but that means that to do it properly, placing the throttle before the charger wasn't an option. So the other way to go was to use the charger as a turbo. And this is where we're at. But the option to just use a blowoff valve like on a turbo isn't OK, because the charger is spinning constantly and the roots design doesn't allow air to reverse its flow back through the charger (like turbos or centrifugal superchargers surging). Which means a high flow valve has to be added and has to be operated in sync with the charger operation - just like a bypass valve. But without a vacuum feed at the charger inlet the only vacuum feed can be the intake manifold - which isn't OK, because the vacuum there doesn't have a direct relation to the supercharger load with the throttle between the two. That's where the cable operation comes into play - with a cable connected directly to the throttle and operating the bypass valve with the correct ratio, you can have a fully synced system, where the supercharger never loads up unnecessarily and you essentially have a boost controller attached to your right foot - the more throttle you apply, the more boost you'll have. An ingenious solution, hats off to TTE engineers.
I've also written an extensive explanation why the vacuum bypass often causes issues, especially at higher boost levels. I've seen this too many times to count, so here goes:
The Mini Cooper vacuum bypass valve, used in most DIY supercharging applications for the Lexus IS200 introduces several problems:
- Unwanted acceleration (at part throttle the car may tend to accelerate on its own at full boost without additional throttle application)
- Bad throttle response (it's either ON or OFF, no middle ground, making the car tricky to drive and sometimes dangerous)
- Limp mode issue (when trying to feather the throttle and balance the boost the car often goes into limp mode and you have to stop, turn off the engine, wait a couple of seconds and start it again)
- Impossible to cruise at motorway speeds (the unwanted acceleration problem and limp mode problem)
- Traction control almost always triggers limp mode
After extensive tests, we found out that the problem is in the vacuum bypass valve and its relation to the throttle operation. In the genuine TTE kit there's a direct (almost linear) relation between the throttle operation and the bypass operation (closed throttle=open bypass and vice versa). This is done by mechanical cable.
With the vacuum bypass valve the end points of this relation are the same (closed throttle=open bypass and WOT=closed bypass), but the problem lies in between those 2 end points - the relation isn't linear.
The problem occurs at different throttle positions depending on the vacuum bypass valve spring strength but usually at about 30-35% throttle - say you're trying to keep a constant speed, which requires about 35% throttle and the following happens:
1. 35% throttle gives you about -0.2 bar vacuum in the intake manifold, which gives you the perfect amount of power to maintain your speed
2. At -0.2 bar the vacuum bypass valve starts closing;
3. With the partially closed bypass valve, the pressure in the intercooler and piping rises;
4. With the pressure before the throttle body raised, more air starts to go through the partially open throttle body (throughput = area x pressure);
5. With more air coming through the throttle body, the pressure in the inlet manifold rises;
6. Raised pressure in the inlet manifold means the bypass valve closes even more;
7.With the bypass valve closed even more, the pressure in the IC and piping rises even more;
8. This process continues exponentially until the bypass valve closes fully. Now the bypass valve is closed at 35% throttle (while on the cable operated bypass this should be at over 80% throttle).
9. With the bypass fully closed, the pressure in the IC and piping rises exponentially - the air has nowhere to go except through the small throttle opening;
10. With pressure before the throttle body rising, the pressure in the inlet manifold continues to rise.
11. The ECU has a failsafe threshold for the relation between TPS and MAP sensor readings, so at low TPS readings (partially closed throttle body) the MAP sensor should read no more than a certain amount of pressure (or vacuum, if we're taking atmospheric pressure as a reference). This is because in the event of inlet manifold mechanical failure (say we make a hole in the manifold, or disconnect a large vacuum line), the engine gets enough air to rev freely even if we don't apply the throttle. In this event, the ECU cuts fuel and ignition timing, so the engine doesn't overrev itself or unwanted acceleration doesn't occur. And at this exact moment at 35% throttle, the MAP sensor reads too high inlet manifold pressure, so this failsafe is triggered, also known as limp mode.
The way to avoid that is to have a bypass valve, which has direct and linear relation to the throttle body and not inlet manifold pressure. This is where this kit comes into play – it mimics the operation of the original TTE bypass valve to the fullest, so it eliminates all problems explained above in one go. A simple and elegant solution to a very annoying problem.
I hope I've been of some help...
The only time my car went into limp mode is when I blew my precats into the pipe blocking it.
On motorways which I do mostly it drives fine cruising at 70 80 without any issues at all.
I even tow caravans on it without any undue Acceleration, a few people have driven my car and same again it cruises at all speeds without major issues.
I'm sure the cable operated system is much better and is more like the tte kit in every way.
A great write up and explanation
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![[Image: FB_IMG_1474048273787_zpsnbfq6a3s.jpg]](http://i1227.photobucket.com/albums/ee440/davis5835/Mobile%20Uploads/FB_IMG_1474048273787_zpsnbfq6a3s.jpg)
All the problems you listed above using a vacuum bypass valve I have never had.
The only time my car went into limp mode is when I blew my precats into the pipe blocking it.
On motorways which I do mostly it drives fine cruising at 70 80 without any issues at all.
I even tow caravans on it without any undue Acceleration, a few people have driven my car and same again it cruises at all speeds without major issues.
I'm sure the cable operated system is much better and is more like the tte kit in every way.
A great write up and explanation
sent from Admin HQ via tapatalk
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