Too much boost problem!
Discussion
I have 1990 Turbo Carbed version. According to my owners manual, it say that my boost should not exceed 0.65 Bar and if it does, I should consult my Lotus dealer. Since I bought it, when I put my foot down, I ca get almost 1.0bar quite easily. With not knowing much about Esprits and turbos thought that because the gaude read 1.0Bar and the needle going to the max, it wasn't a proble. Have I got a problem?
I generally drive it like a normal car and accelerate in short spirts, never prolonged.
The car appears to be extremely quick and was surprised to learn that it was only 215BHP. There's a guy around the corner from me with a Porsche 911/996 96 model (Iam not sure). The other week he tried to leave me standing but to his amazement, it was quite the opposite.
If the design boost should be limited to 0.65Bar, I don't want to blow the turbo, any advise please?
I generally drive it like a normal car and accelerate in short spirts, never prolonged.
The car appears to be extremely quick and was surprised to learn that it was only 215BHP. There's a guy around the corner from me with a Porsche 911/996 96 model (Iam not sure). The other week he tried to leave me standing but to his amazement, it was quite the opposite.
If the design boost should be limited to 0.65Bar, I don't want to blow the turbo, any advise please?
Dave,
You won't blow the turbo, it is capable of providing much more boost than it's application in an Esprit allows for. What you will blow are your carburettor seals and possibly the head gasket.
I am not very familiar with the set-up on your car, but suspect that your gauge may be innacurate or, if you have an integral wastegate on your turbo, the actuator rod may be misadjusted, or your wastegate is sticking. It is also possible that, as you state you usually only come on max boost for short periods, you are peaking at 1.0Bar and then would fall back to a steady 0.65Bar, have you stayed on boost and observed what happens? Hope this helps. Happy Motoring! Jim'85TE
You won't blow the turbo, it is capable of providing much more boost than it's application in an Esprit allows for. What you will blow are your carburettor seals and possibly the head gasket.
I am not very familiar with the set-up on your car, but suspect that your gauge may be innacurate or, if you have an integral wastegate on your turbo, the actuator rod may be misadjusted, or your wastegate is sticking. It is also possible that, as you state you usually only come on max boost for short periods, you are peaking at 1.0Bar and then would fall back to a steady 0.65Bar, have you stayed on boost and observed what happens? Hope this helps. Happy Motoring! Jim'85TE
Thanks Jim,
Iam not that familiar with the parts yet but I think that there may be a problem with the rod connecting the wastegate. Is this circular with a rod c/w split pin connected? If so, the split pin has broken leaving the actual pin inside the hole. I will have to drill it out this weekend and put a new pin in. Should the rod have any movement/pivet with the pushrod it's connected to, mine doesn't? I hope Iam talking about the right thing here
Iam not that familiar with the parts yet but I think that there may be a problem with the rod connecting the wastegate. Is this circular with a rod c/w split pin connected? If so, the split pin has broken leaving the actual pin inside the hole. I will have to drill it out this weekend and put a new pin in. Should the rod have any movement/pivet with the pushrod it's connected to, mine doesn't? I hope Iam talking about the right thing here
Jim, the boost gauge only stays at 1.0Bar for a few seconds maybe 5 seconds or so then I have to shift gears, it goes down to about 2/3 if Iam in gear long enough. With my height, my head touches the glass roof which means that I cannot see the dials properly! Most of the time, Iam concentrating trying to keep the car under control when the turbo really kicks in.
I will reassess the readings on the weekend if it's not raining or sooner if possible and report back.
Based on the information i've given you, do you think I have a problem?
I will reassess the readings on the weekend if it's not raining or sooner if possible and report back.
Based on the information i've given you, do you think I have a problem?
It sounds to me like the p.o may have "shimmed" your wastegate to get a little more performance out of it. If your wastegate is like mine ( 88 my) look under the wastegate (from under the car) and see it there is a bolt right in the bottom of it. If there is, then it has been shimmed. You can back it out by 1/4 at a time to slowly adjust your boost accordingly. A stock esprit has no bolt in the wastegate on the bottom. This could be as of no use to you as your set up might be different than mine.
Happy Super Boosting!
Dino
Happy Super Boosting!
Dino
cnh1990 said: I'll send a pic as soon as I can. It is snowing hard at this time. I don't know if I can get to it today.
Calvin
Calvin, found the adjuster in the rod. It was right in front of me. I was trying to describe off memory. looks pretty rusted. I won't try to make any adjustment myself as Iam still a novice. I will see if the boost gauge stays at 1.0Bar or if this is only for a brief moment. If it is, is this ok?
How easy is it for the rod to come off the end when the split pin is broken? Need to get it fixed this weekend really don't I?
Couldn't wait. Just had a quick look with a torch (flashlight) and a mirror, also used my hands to feel but nothing there. Could the po adjusted the rod to make it longer?
Should I book it into a Lotus garage?
Should I book it into a Lotus garage?
espritnutdean said: It sounds to me like the p.o may have "shimmed" your wastegate to get a little more performance out of it. If your wastegate is like mine ( 88 my) look under the wastegate (from under the car) and see it there is a bolt right in the bottom of it. If there is, then it has been shimmed. You can back it out by 1/4 at a time to slowly adjust your boost accordingly. A stock esprit has no bolt in the wastegate on the bottom. This could be as of no use to you as your set up might be different than mine.
Happy Super Boosting!
Dino
Dave
You should not see 1.0 bar even with your foot to the floor. When you change gear the guage will hit the end stop but return to about 0.65 almost as fast as you can see it. Mine was in the garage a couple of weeks ago with a sticking wastegate which was caused by a bent accuator rod. I was getting too much boost at times but also it was casuing the wastegate to stay open and I was loosing boost. I'd get it fixed as soon as you can otherwise you could do quite a lot of damage.
Adrian
www.adrianmugridge.co.uk
You should not see 1.0 bar even with your foot to the floor. When you change gear the guage will hit the end stop but return to about 0.65 almost as fast as you can see it. Mine was in the garage a couple of weeks ago with a sticking wastegate which was caused by a bent accuator rod. I was getting too much boost at times but also it was casuing the wastegate to stay open and I was loosing boost. I'd get it fixed as soon as you can otherwise you could do quite a lot of damage.
Adrian
www.adrianmugridge.co.uk
I would drive it casually until you figure this one out, I will look through some of my lit. to see if you have the same wastegate as mine (external). If you hear any pinging, back off it!! You can quickly toast the engine, believe me, I'm rebuilding right now due to a lean condition at high rpm.
Good Luck,
Dino
Good Luck,
Dino
Oh, the wastegate is forward of the left rear wheel. If you follow from the exhaust manifold down, the wastegate is at the lowest part of the exhaust and is shaped a bit like a little bucket, the bottom of it should have a hole w/ threads in it, if it has a bolt in it, you have found the culprit. If you reach under from in front of the left rear tire, you can feel the bottom of the wastegate. I hope this helps.
Dino
Dino
espritnutdean said: I would drive it casually until you figure this one out, I will look through some of my lit. to see if you have the same wastegate as mine (external). If you hear any pinging, back off it!! You can quickly toast the engine, believe me, I'm rebuilding right now due to a lean condition at high rpm.
Good Luck,
Dino
Dino,
All wastegates are external, but later model Esprits have a wastegate which is 'intergral', that is, it is attached directly to the turbo housing. Those that are intergral are actuated by a rod which is adjustable. The wastegate you have is the same as mine, it is connected in the exhaust loop just aft of the exhaust manifold. One disadvantage of this is that any condensation in the exhaust system will settle and condense here, this has the effect of corroding the plunger and spring making them operate with lesser efficiency over time. Happy Motoring! Jim'85TE
espritnutdean said: It sounds to me like the p.o may have "shimmed" your wastegate to get a little more performance out of it. If your wastegate is like mine ( 88 my) look under the wastegate (from under the car) and see it there is a bolt right in the bottom of it. If there is, then it has been shimmed. You can back it out by 1/4 at a time to slowly adjust your boost accordingly. A stock esprit has no bolt in the wastegate on the bottom. This could be as of no use to you as your set up might be different than mine.
Happy Super Boosting!
Dino
Dino,
Hate to disagree with you, but what you are describing are adjustable and non-adjustable wastegates.
The existence of a cap bolt protruding through the bottom of your wastegate simply means that it is an adjustable wastegate and therefore requires no 'shimming'. To vary the amount of boost pressure required to open the wastegate, you adjust the length of the cap bolt. The advantage being that you can vary the wastegate pressure both up and down.
On a non-adjustable wastegate, the opening pressure is fixed by the strength of the spring on the wastegate plunger. You can disassemble the wastegate and place a shim under the spring which compresses it upon reassembly and once shimmed, it requires greater boost pressure to open the wastegate. Your turbo must now produce more boost to open it. The size of the shims is calibrated to require a fixed amount of opening pressure and consequently a greater amount of boost. It has the disadvantage of not being able to lower the boost pressure beyond the initial strength of the spring.
Lotus used both types of wastegates on Esprits interchangeably. One interesting note, if you look at the spec. plate on the wastegate, you'll see it has a 'base' setting of 7PSI. Since the Esprit runs with a minimum of 8.5PSI of boost, the non-adjustable wastegates already have a shim in them to allow this. Adjustable wastegates have merely been calibrated to 8.5PSI using the cap bolt. To increase a non-adjustable wastegate beyond 8.5PSI, you remove the existing shim and replace it with a thicker one. Happy Motoring! Jim'85TE
Cheers Jim, that's great advise! Iam going to see what readings I get today if I can get out. It appears that I have an integral wastegate as it's quite high up and it looks like it's connected to the turbo. The rod has a nut half way down as though I can adjust it.
Any advise on my current readings?
I've taking a quick pic not sure whether this will work. it's my first time!
[pic]www.community.webshots.com/image5/5/55/58/6285558RZssHN_ph.jpg
Any advise on my current readings?
I've taking a quick pic not sure whether this will work. it's my first time!
[pic]www.community.webshots.com/image5/5/55/58/6285558RZssHN_ph.jpg
Just uploaded some Service notes for the turbo. Should be helpful. Page takes a while to load if you're on a modem. I can email the jpegs if you send me your email. Pics of the wastegate and turbo, plus plenty of text.
kato
www.lotusespritworld.co.uk/maintenance.html
kato
www.lotusespritworld.co.uk/maintenance.html
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