esprit se turbo boost

[danny tattersall]

My 1993 esprit turbo se is boosting @ 4 psi of pressure to maintain steady speeds of 70 mph on level stretches of motorway. I would expect there to be vacuum pressure, not positive boost, once you have accelerated upto and then hold this speed. I have tried adjusting the wastegate actuator rod - lengthening it slightly which helps a little, but am still not happy. The car has covered 55000 miles, runs like a dream apart from this, and has a full lotus service history. In fact it has just had a major service and cam belt replacement less than 1000 miles ago. Anybody got any suggestions please?

[wcdeane]

My '91 SE does the same thing. But I have a MK5 S4S chip, which makes more liberal use of boost. I just thought that it was normal. Like you perhaps, initially I was concerned about fuel economy, and ware and tear on the turbo. But the darn thing is so much fun to drive that I really don't care very much anymore.

Does anyone know if there is anything to be concerned about here...and are we giving up some fuel economy with this condition?

[cnh1990]

There is a little bit of boost on mine. Not much more on a silght uphill grade than level. Hard to tell as the gauge is not real acurate around there. But 4 PSI is about normal. Just remeber our engines have a little less compression than an N/A type of engine, thats why when we loose our turbo our cars are really flat. I had one guy comment on loosing boost that he thought it would drive like a N/A and wondered if that is what a N/A car felt like as it really sucked. That is not true. When we loose our turbo our performance is quite lower than an N/A.
Calvin

[danny tattersall]

Thanks for the replies. Regarding the fact that the compression is slightly lower than a NA car I agree that the vacuum would not be quite as strong on a turbo motor. However, from past experience with turbo cars eg a heavily modified 300 bhp Rover 220 turbo coupe which I owned, I used to have a -10 mm of mercury vacuum when cruising at 80 mph or so. My esprit SE may also have been chipped without my knowing as the performance is very good and boost builds extremely quickly. It was the poor fuel economy that drew my attention to the boost pressure initially. Obviously you do not buy a car like this to do 40 mpg, however, I drove it to work 80 miles a day for 4 days on motorways with no traffic at an average speed of 65 mph and just about averaged 20 mpg with a very frugal driving style - significantly below the official figure of around 29 mpg at 75 mph. I was just wondering whether this is still normal because the boost seems excessive. The accelerator pedal also has barely any travel to do 80 mph also. It is very difficult to choose a speed and stick to it exactly because the boost comes in so quickly that it acts almost like an on/off switch than a progressive throttle! Cheers Guys, any more ideas?

[PatHeald]

Danny,

Where do you get the car serviced, or do you do it all yourself?

I am also in Lancashire, but I've not had my Esprit long enough to have to resort to a specialist.

Cheers,

Pat 87TurboHC

[danny tattersall]

PAT,

I will be getting my car serviced at Ribble Valley Lotus in Rishton near Blackburn. Their phone number is [phone]. They are an official dealer and although their servicing is quite expensive it is worthwhile going there because it is local - saves the hassle of travelling loads of miles and possibly having to take time off work just to drop the car off for servicing ( which obviously could more than offset any savings that you could have made ). Any other work I will carry out myself. I am an aircraft engineer and am therefore used to doing impossible jobs with zero access requiring double jointed limbs and three pairs of hands!! Does your HC boost anything like mine?

[PatHeald]

You are asking quite a subjective question to a person who has not driven any Esprits other than my own.

I don't have any problem holding constant speeds and the throttle is certainly not like an on/off switch.

When the boost comes in you really know about it, but there is always a noticable lag and the throttle response is slow compared to, say, a BMW 328.

My only previous experience of turbos has been on diesels.

I am pretty confident that my car is absolutely standard, so if you want to compare it to your own you can have a run in it with pleasure.

The car is off the road at the moment, waiting for the radiator to be reconditioned, but once it is back in one piece I am hoping to start using it properly.