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bens4s

manual boost controller?

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I've searched a few other posts where manual boost controller is mentioned. I have one that im interested in installing. Its just an in line grimmspeed controller. In and out. Has anyone installed one similar and what pros /cons should I expect. Other than overboosting. I will start on the lowest setting and work up to 17-18 psi. I want more consistent boost. I've already upgaded just about everything to handle it. Turbo,pistons,exhaust, intake,...

Any opinions would be great.

Thanks

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Well.. I've installed it and so far it's working perfectly. Im at 15psi now and blew off some hose caps. Time to resecure everything and go for 17-19 psi. I won't go over 19. Its already breaking the tires loose in first three gears. My rears are 20x10

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I would not do that unless you have done something to verify the A:F, modified the ECU programming for a 3Bar sensor, and added more fueling!!!

 

The ECU controls boost via the boost control frequency valve connected to the wastegate.  That is a PWM (pulse width modulated) computer controlled bleed valve, much better than a manual boost controller.

 

The real problem with increasing boost is that the tables for the map sensor in the ECU are limits to that 2Bar MAP sensor!  The Esprit boost is already at the limits of that MAP sensor, if you increase boost beyond the limits of that sensor, then the fuel flow will not be correct for that much boost, and you will go lean.  The ECU has control over the boost normally, and it will try to protect the engine from overboost, or a lean condition, but it you add a manual bleed valve as a second boost controller, then you take that ability away from the ECU.

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I have installed the red race chip. It ups boost to 1.25 bar. That's a little over 19 psi. I don't plan on exceeding that amount. I just want max boost any time I want. I also have a stage 2 turbo, bov, ram air, free flow exhaust, poly/ceramic coated pistons, reverse cam gear,high flow injectors, msd,electric chargecooler pump, new radiators... I just ordered software and plug for freescan to monitor what its actually doing. Im finally impressed with the speed of the car after making this change. The original solenoid is still in place ready to be hooked back up if I change my mind.

Hopefully this gives a little more info.

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I'm puzzled Ben. In your wastegate topic, you said you have hardly driven the car in 2 years. Why are you making all these changes when you have hardly driven the car and in fairness may not even properly know how it goes stock?

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The drives I've taken have been to the corner store and back. When I floored it, it seemed slow. Slower than my lightly modded m3. Something wasn't right. I work 7 days a week, so when I get 10 minutes to drive, I want it fast and fun. I started upgrading the car to find the weak link. All I needed was an experienced tech working on it. The reason it was slow is because of electrical issues. No cel due to po unplugging it. Its been a nightmare spending all this time/money to improve it with no results. This forum is the only reason I have it actually running well at this point. Still with some issues.

I've followed dermots page for upgrades. Its an older car, and I want it perfect. Im a little ocd with my cars. I was told this is as good as it gets. I wasn't satisfied with that. Owners on the forum talk of how fast there cars are and I knew something wasn't right. With the forums help, I've proved it. There's not a lot of mechanics willing to take liability working on these cars. Mines 1 of 12 and they get scared.

Edited by bens4s

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I hope yall understand I'm not trying to ruin the integrity of the car. I just want it as durable and modern as possible. Price has not been an issue. Everything I've done has been in hopes of making it better and more my style. Any other upgrades that I've forgotten, please advise ;)

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I have installed the red race chip. It ups boost to 1.25 bar. That's a little over 19 psi. 

 

No it really doesn't.

 

The MAP sensor is the limiting factor.  The boost cut limit is 2.07Bar, the ECU will cut fueling at 2.07Bar period, even with the Red Race "1.25Bar chip".

 

Within that 2.07Bar is not 2.07 Bar of boost, that is total Absolute MAP, including the relative atmospheric pressure.  IIRC in reality the boost limit works out to 1.06Bar of boost max before fuel is cut (depending on altitude, due to relative atmospheric pressure).

 

So if you use a manual boost controller to exceed 1.06Bar of boost (15.5psi), then you run the risk of running the engine lean and easily damaging it.

 

If your manual boost controller takes away the ability for the ECU to open the wastegate and reduce boost to safe leveles, then you will definitely damage the engine.

 

BTW, freescan MAP values are not calculated correctly, so you will see a MAX of 2.24 bar in Freescan which equates to 2.07 in Espritmon or tunerpro.  Freescan is great to use to log data and email it to someone else to graph and take a look at your engine, Espritmon is a pain to do that.

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Again, if the car has not been running correctly and you have only taken drives to the shops, you will not know its performance or capabilities.

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I understand. I can't know the capabilities other than reading the reviews of other owners. No one else around here has an s4s, or s4 that I've met. Im sure there out there. As long as I've owned it and the time its spent at a mechanic, I'm done with mediocre. I'll force it to run the way it should on its own. So far at 14 psi, its more than enough. The wheels break free easily. Before, it couldn't peel out in first. Im left with no other options.

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I would start by getting a copy of the Shop manual, especially the EMH section and read it like a book.  It's a great reference.  Also of course asking questions like yo are doing.  there are some great Lotus guys in Texas, but it is a big place!


oh, and I would install an A:F meter!  With the mods you are doing, you NEED to know that it isn't going lean.

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If you are not attaining the factory 1 bar of boost then I suggest finding out why rather than bypassing the factory boost control. Otherwise you may end up causing further problems.

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Good point Derek,

 

Bens4s,

 

What boost were you getting to before you added the boost controller?

And what check engine codes did you have, since the P.O. had removed the check engine bulb?

 

The Lotus ECU will also restrict boost due to a few things like too low of coolant temperature (must be above 77C, thermostat must be 82C) and to protect the engine from a lean condition (fuel pressure, etc).

 

So cranking up the boost with a manual boost controller, especially to overcome a too low boost due to the ECU restricting boost to save the engine, can be really dangerous.

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Next step is a dyno. Hopefully that will tell me how lean im going. I did fix the issue causing lack of full boost Using a new solenoid. I installed the manual controller to allow 1.25 bar. Im pretty happy at 14psi though. I'll post the dyno results when done next week. Was at 227 hp when I got the car. Im hoping for about 100 more.

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I don't have freescan to check codes. Until just recently, I didn't know that I even had a problem. Other than the car being slow. The old boost gauge was inconsistent so I just replaced it with a digital. I know fuse 11 was missing. Replaced it and all solenoid on that circuit. Boost then went to 14 psi at max throttle. I still have cel on though. I ordered freescan stuff today to figure out why. It must be something simple to not restrict boost though. This was before I installed the boost controller.

Edited by bens4s

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Well...hooked the solenoid back up. Only get 10-11 psi in first two gears. Not as much fun, but I guess I won't blow it up. Thanks for talking me out of it.

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10psi is ~.68Bar.

 

The manual wastegate adjustment spec is for .65Bar without interference from the ECU (allowing more boost).  So if you are only getting ~.65Bar, then the ECU is possibly restricting boost to protect the engine.

 

What is your coolant temperature once the car is warmed up?

 

Do you get any sudden boost cut and or any back firing or bucking?

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No backfire and coolant was around 80. I didn't drive it long as it was late. The day before I had 14psi with solenoid. Possibly I didn't get high enough in rev. Ill try again this afternoon.

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I would like to thank all of you very much. I manually engaged the cel codes. I had 26. I looked over everything and found the secondary resister missing. I replaced it and now no cel. I have the oem boost solenoid in also. With all the other upgrades I've done, holy sh this thing flies!

Finally I'm impressed!!

Thank you!!!

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