How much boost?
Discussion
Hi,
1.2 BAR? Isn't that just on overboost, not sustained? If memory serves me the static boost is 0.88 BAR or 1.0 BAR.
I am running 0.69 BAR (10.0PSI) on my carb'd '85 versus a stock 0.51 BAR (7.5PSI). Any more than that and on a non-intercooled engine I would begin to have some issues with detonation. Happy Motoring!... Jim'85TE
1.2 BAR? Isn't that just on overboost, not sustained? If memory serves me the static boost is 0.88 BAR or 1.0 BAR.
I am running 0.69 BAR (10.0PSI) on my carb'd '85 versus a stock 0.51 BAR (7.5PSI). Any more than that and on a non-intercooled engine I would begin to have some issues with detonation. Happy Motoring!... Jim'85TE
Hi,
Again, I believe that those reporting 1.2 Bar are talking about the overboost. This overboost condition is allowed by ther ECU for about 3 sec., providing the chargecooler temp is within defined limits (85°) I believe, and then the ECU limits it to 1.0Bar. So they are actually running 1.0Bar as the usual maximum boost. Happy Motoring!... Jim'85TE
Again, I believe that those reporting 1.2 Bar are talking about the overboost. This overboost condition is allowed by ther ECU for about 3 sec., providing the chargecooler temp is within defined limits (85°) I believe, and then the ECU limits it to 1.0Bar. So they are actually running 1.0Bar as the usual maximum boost. Happy Motoring!... Jim'85TE
Jim, actually, that is not an overboost condition with the chips that Markus, Sanj, and I have made. The race chip will allow 1.2 bar sustained and this does not have to be activated by getting the ECU into overboost mode.
I typically run a 1.1 bar max chip on a daily basis and it is available anytime that other parameters allow it. No trickery needed. Just mat it to the floor. In cool weather it is fantastic and provides it all the time (<70F). But, the kicker comes in hot weather where it will not be allowed very often as you've noted.
And, the problem will show up much more frequently when you try to get 1.1 and 1.2 bar of boost with the stock turbo. Your output temp will be high and surging will probably occur. The stock compressor stage isn't efficient at these levels and cannot sustain it for long periods of time. But, that isn't the chips' limitation as it will allow it as long as other parameters are not high - like intake charge temp.
But again, it isn't an overboost condition. Those in cooler climates can enjoy it year round whenever the urge stikes them.
Ron
1990 SE
>> Edited by rlearp on Saturday 21st February 21:55
>> Edited by rlearp on Saturday 21st February 21:57
I typically run a 1.1 bar max chip on a daily basis and it is available anytime that other parameters allow it. No trickery needed. Just mat it to the floor. In cool weather it is fantastic and provides it all the time (<70F). But, the kicker comes in hot weather where it will not be allowed very often as you've noted.
And, the problem will show up much more frequently when you try to get 1.1 and 1.2 bar of boost with the stock turbo. Your output temp will be high and surging will probably occur. The stock compressor stage isn't efficient at these levels and cannot sustain it for long periods of time. But, that isn't the chips' limitation as it will allow it as long as other parameters are not high - like intake charge temp.
But again, it isn't an overboost condition. Those in cooler climates can enjoy it year round whenever the urge stikes them.
Ron
1990 SE
>> Edited by rlearp on Saturday 21st February 21:55
>> Edited by rlearp on Saturday 21st February 21:57
rlearp said:
Jim, actually, that is not an overboost condition with the chips that Markus, Sanj, and I have made. The race chip will allow 1.2 bar sustained and this does not have to be activated by getting the ECU into overboost mode.
I typically run a 1.1 bar max chip on a daily basis and it is available anytime that other parameters allow it. No trickery needed. Just mat it to the floor. In cool weather it is fantastic and provides it all the time (<70F). But, the kicker comes in hot weather where it will not be allowed very often as you've noted.
And, the problem will show up much more frequently when you try to get 1.1 and 1.2 bar of boost with the stock turbo. Your output temp will be high and surging will probably occur. The stock compressor stage isn't efficient at these levels and cannot sustain it for long periods of time. But, that isn't the chips' limitation as it will allow it as long as other parameters are not high - like intake charge temp.
But again, it isn't an overboost condition. Those in cooler climates can enjoy it year round whenever the urge stikes them.
Ron
1990 SE
>> Edited by rlearp on Saturday 21st February 21:55
>> Edited by rlearp on Saturday 21st February 21:57
Ron,
Thanks for taking the time to enlighten me with your wonderful explanation. I am not as knowledgeable of the newer cars as of the earlier ones.
I always look forward to hearing from those who can teach me about the more current hardware. Thanks again. Happy Motoring! ... Jim'85TE
>> Edited by lotusguy on Sunday 22 February 07:45
I have one of these '300bhp chips'on my SE. Funny thing is when I got the car rolling roaded it only had 263bhp.
torque was up at 297lb which was nice.
I tried turning my boost up with the aid of a bleed valve but it never seemed to feel right, turns out you cant use these on esprits so I got a collins actuator and shortend the rod and it hits 1.2bar but dont hold it.
Anyway car is running like a complete bag of sh*t at the moment.
torque was up at 297lb which was nice.
I tried turning my boost up with the aid of a bleed valve but it never seemed to feel right, turns out you cant use these on esprits so I got a collins actuator and shortend the rod and it hits 1.2bar but dont hold it.
Anyway car is running like a complete bag of sh*t at the moment.
Keep in mind the chip rating is at the FLYWHEEL, not at the rear wheel which is what you're meauring on your rolling road, or as we yanks call it, chassis dyno.
That sounds about about right for a 300hp chip. I was making 267 rear wheel with a similar chip and if you add in about a 11% (I know this is debatable, I'm using 11%, most like to use 15%, 18%, and 20%) loss factor you'd be around 290 hp at the flywheel. Not bad.
Depending on the chip there is more to be had. I started with a Hi Torque chip from Moto-Concept but found it was REALLY rich throughout the range, around 10:1 and even 8:1 in some places. Over the months with the help of the GM fellows (GM computer you know) I learned how to program my own chips and now I have a similar program but without the richness. The result - 289 rear wheel hp with a nice 12:1 ratio - good horsepower picked up for just correcting the A/F. No other changes were needed. That is where the car sits now until I can do a hybrid turbo upgrade to stop the boost surging, another horsepower loss-leader.
Best,
Ron
>> Edited by rlearp on Sunday 22 February 14:10
That sounds about about right for a 300hp chip. I was making 267 rear wheel with a similar chip and if you add in about a 11% (I know this is debatable, I'm using 11%, most like to use 15%, 18%, and 20%) loss factor you'd be around 290 hp at the flywheel. Not bad.
Depending on the chip there is more to be had. I started with a Hi Torque chip from Moto-Concept but found it was REALLY rich throughout the range, around 10:1 and even 8:1 in some places. Over the months with the help of the GM fellows (GM computer you know) I learned how to program my own chips and now I have a similar program but without the richness. The result - 289 rear wheel hp with a nice 12:1 ratio - good horsepower picked up for just correcting the A/F. No other changes were needed. That is where the car sits now until I can do a hybrid turbo upgrade to stop the boost surging, another horsepower loss-leader.
Best,
Ron
>> Edited by rlearp on Sunday 22 February 14:10
Anyway I do want 300bhp, so what do you suggest I do?
I have a air/fuel ratio gauge that tells me the car runs rich under load, I also have since fitted a 3" diameter stainless steel exhaust with cat and EBVEVBRBE valve thing whatever its called removed.
It has a carbon dynamic airfilter with direct cold air feed, uprated charge cooler pump, 300bhp chip and a collins uprated actuator. Im planning on taking it back to the place where I got it rolling roaded (engine advantages) to have him set it up.
Any tips on what needs to be done?
I have a air/fuel ratio gauge that tells me the car runs rich under load, I also have since fitted a 3" diameter stainless steel exhaust with cat and EBVEVBRBE valve thing whatever its called removed.
It has a carbon dynamic airfilter with direct cold air feed, uprated charge cooler pump, 300bhp chip and a collins uprated actuator. Im planning on taking it back to the place where I got it rolling roaded (engine advantages) to have him set it up.
Any tips on what needs to be done?
rlearp said:
Depending on the chip there is more to be had. I started with a Hi Torque chip from Moto-Concept but found it was REALLY rich throughout the range, around 10:1 and even 8:1 in some places. Over the months with the help of the GM fellows (GM computer you know) I learned how to program my own chips and now I have a similar program but without the richness. The result - 289 rear wheel hp with a nice 12:1 ratio - good horsepower picked up for just correcting the A/F. No other changes were needed. That is where the car sits now until I can do a hybrid turbo upgrade to stop the boost surging, another horsepower loss-leader.
I noticed the same thing with my high-torque chip. Switched over to the 330HP chip and everything cleared up and the car becamefun to drive again.
12:1 is getting pretty lean. Is that on race gas, 93 pump gas, or 100 pump gas? What is the max boost you are running? Do you have a scan of the 289HP dyno run? I'd love to see it and where your curves are at.
Hi, the first scan, the 267 hp scan is already on the net and it is fairly old. You can check it here:
<a href="http://www.gt40s.com/images/lotus/lotusearp.jpg"><a href="http://www.gt40s.com/images/lotus/lotusearp.jpg">www.gt40s.com/images/lotus/lotusearp.jpg</a></a>
There are also a bunch of pics in that directory under www.gt40s.com/images/lotus/ if you want to look at them.
Check out where it hits less than 10:1, off the bottom of the graph, in some places. Some of it is due to boost surge, some of it due to fuel map and the injector duty cycle being so high in open loop mode.
The later graph which I'll try and get scanned does around 284-289 and the A/F gets as high as 12:1, but is between that and 10.5:1. It never looks like this plot, it is a smoother curve. I bundled all my documentation together in a folder when I was going to sell the car but ended up not having too, thankfully, and I think it is in there so I'll try and pull it.
Now, before people get all crazy and over-analyze stuff regarding dyno numbers keep in mind these are comparitive numbers on different days, but on the same dyno. Temps were close to the same and the second set of runs (three months after) with the modded chip was done on pump gas. Max boost is 1.1 bar with all runs. The exhaust is a 2.5" manderel bent system that I welded up and is fairly low restriction. No cat, which helped the car a lot, and no valve. This isn't about dynos so let's not open that can of worms.
Kev I'm not sure what is up with yours, besides the obvious difference of yours and my dynos being different. If you don't like dynos have you done a quarter mile, timed/offical track? Trap speed is a pretty good indication of hp. I can turn a 109 quarter which seems indicative of the hp and dyno numbers. I'd figured your car should make around 260-270 at the wheels with those mods. The things I would ask you to check, chargecooler working, exhaust, etc. seem okay.
How is your turbo condition? Have you checked compression and done a leakdown analysis? Has the timing belt ever been off - if so do you know if the cam timing is correct, this could kill some power. How does the car feel - does it pull smoothly once the boost has peaked? Are you sure that chip is different and not a stocker for some strange reason? I'd expect a stock Esprit to put down around 215-225 at the wheel depending on whatever percentage loss you factor. Yours seems to be in this this range. Can anyone collaborate on the stock rear wheel hp numbers for a SE?
Ron
>> Edited by rlearp on Monday 23 February 01:51
<a href="http://www.gt40s.com/images/lotus/lotusearp.jpg"><a href="http://www.gt40s.com/images/lotus/lotusearp.jpg">www.gt40s.com/images/lotus/lotusearp.jpg</a></a>
There are also a bunch of pics in that directory under www.gt40s.com/images/lotus/ if you want to look at them.
Check out where it hits less than 10:1, off the bottom of the graph, in some places. Some of it is due to boost surge, some of it due to fuel map and the injector duty cycle being so high in open loop mode.
The later graph which I'll try and get scanned does around 284-289 and the A/F gets as high as 12:1, but is between that and 10.5:1. It never looks like this plot, it is a smoother curve. I bundled all my documentation together in a folder when I was going to sell the car but ended up not having too, thankfully, and I think it is in there so I'll try and pull it.
Now, before people get all crazy and over-analyze stuff regarding dyno numbers keep in mind these are comparitive numbers on different days, but on the same dyno. Temps were close to the same and the second set of runs (three months after) with the modded chip was done on pump gas. Max boost is 1.1 bar with all runs. The exhaust is a 2.5" manderel bent system that I welded up and is fairly low restriction. No cat, which helped the car a lot, and no valve. This isn't about dynos so let's not open that can of worms.
Kev I'm not sure what is up with yours, besides the obvious difference of yours and my dynos being different. If you don't like dynos have you done a quarter mile, timed/offical track? Trap speed is a pretty good indication of hp. I can turn a 109 quarter which seems indicative of the hp and dyno numbers. I'd figured your car should make around 260-270 at the wheels with those mods. The things I would ask you to check, chargecooler working, exhaust, etc. seem okay.
How is your turbo condition? Have you checked compression and done a leakdown analysis? Has the timing belt ever been off - if so do you know if the cam timing is correct, this could kill some power. How does the car feel - does it pull smoothly once the boost has peaked? Are you sure that chip is different and not a stocker for some strange reason? I'd expect a stock Esprit to put down around 215-225 at the wheel depending on whatever percentage loss you factor. Yours seems to be in this this range. Can anyone collaborate on the stock rear wheel hp numbers for a SE?
Ron
>> Edited by rlearp on Monday 23 February 01:51
lotusguy said:
Hi,
Again, I believe that those reporting 1.2 Bar are talking about the overboost. This overboost condition is allowed by ther ECU for about 3 sec., providing the chargecooler temp is within defined limits (85°) I believe, and then the ECU limits it to 1.0Bar. So they are actually running 1.0Bar as the usual maximum boost. Happy Motoring!... Jim'85TE
Ditto Ron's explanation Jim. I'm running the "330 HP" chip as well, which gived me the 1.2 sustained boost. However, I don't experience the dropoff at higher temps nearly as much, because I'm not running the stock turbo either. Running a T3/T4 hybrid. So, I get to enjoy the benefits of the 1.2 bar more than most. Someday I'll get around to acquiring one of those bigger chargecooler units, and then I should see even more time at 1.2.
BTW, the turbo does make a pretty big difference. A friend has the same chip with the stock turbo, and his only pegs up to 1.2 for a couple seconds then comes back down. Took him for a ride in mine, and I just bury the boost gauge and it doesn't budge until I let off the throttle. Nice.
BTW, also adding the Euro spec cam pulleys to the equation as we speak (part of my C service.)
Anways, Happy Motoring back atcha!!!
Mike
Nice Ron. I saw that first graph when you had it done. I'd really like to see the improvement the new chip did for you, if you get a chance.
Kev, I would start by checking you timing and do a quick check to make sure the chargecooler is working properly.
Also, where did you get dynoed? Was there any correction or smoothing? This affects final output. Was it a dyno with roller in the ground or a dyno that attached to the hubs. This can be a big one. If on a dyno with rollers, not a big deal, but if on a dynot hat attaches to the hubs, can make a HUGE difference depending on settings.
Kev, I would start by checking you timing and do a quick check to make sure the chargecooler is working properly.
Also, where did you get dynoed? Was there any correction or smoothing? This affects final output. Was it a dyno with roller in the ground or a dyno that attached to the hubs. This can be a big one. If on a dyno with rollers, not a big deal, but if on a dynot hat attaches to the hubs, can make a HUGE difference depending on settings.
madmike said:
Ditto Ron's explanation Jim. I'm running the "330 HP" chip as well, which gived me the 1.2 sustained boost. However, I don't experience the dropoff at higher temps nearly as much, because I'm not running the stock turbo either. Running a T3/T4 hybrid. So, I get to enjoy the benefits of the 1.2 bar more than most. Someday I'll get around to acquiring one of those bigger chargecooler units, and then I should see even more time at 1.2.
BTW, the turbo does make a pretty big difference. A friend has the same chip with the stock turbo, and his only pegs up to 1.2 for a couple seconds then comes back down. Took him for a ride in mine, and I just bury the boost gauge and it doesn't budge until I let off the throttle. Nice.
BTW, also adding the Euro spec cam pulleys to the equation as we speak (part of my C service.)
Anways, Happy Motoring back atcha!!!
Mike
Mike,
I always appreciate it when someone looks at, and addresses, the system as a whole such as you and Ron have done.
Chargecoolers, ECU's, Turbo Upgrades and the like are something I have not really concentrated on given the limitations of my carb'd Esprit. I thoroughly understand the concepts, but am lacking on the details. This is why I enjoy learning what you guys know.
I want to keep my Esprit close to stock, certainly closer than adding dynamic engine controls, chargecoolers and the like. Consequently, short of porting and polishing, I'm about as far as my Esprit will let me go.
Having said that, my car goes about 230 ponies and this is plenty much for me (old Fart, depreciating Adrenal Glands etc.). Still, it's the closest I've come, to the exhilaration I felt in my younger days.
'Course that required a 'G' suit and copius amounts of donated Taxpayer Dollars. If anyone ever wanted to know what it was like flying fighter aircraft, the Esprit is about as close as you can come, and I mean that in all respects,and still be Street Legal.
You're gonna like the Euro Cam timing, but don't raise your expectations too high. It will be Better as opposed to More. Still, an improvement worth making.
Too bad the chips are ROM only, because if you increase the chargecooling capacity, you may not be tapping in to the full potential available. May have to get Ron and Sanj to custom fab a chip w/ new maps for you.
Do let us know how you get on. Happy Motoring! ...Jim'85TE
>> Edited by lotusguy on Monday 23 February 03:22
Thanks Jim, but I have to give credit where credit is due. The PO did a lot of the work, and I'm using that as a base. But I did go out and find the car I was looking for, and paid premium to get it. All according to plan shall we say.
Your advise per the euro cams is spot on. I'm not expecting a huge increase of anything. I'm looking for it to really smooth out the total power curve leading to boost, if anything.
Whereas I'm nowhere in your league regarding car knowledge, the one thing Esprit ownership has taught me is that all things require balance. You can't really just 'upgrade' one thing and expect to get the most out of it.
With regards to the chip, I enjoy Sanj's program very much, but it is my intention to really dyno tune the ECU program for the components I'm running when all is complete. I have a few things engine wise to go (S4s headers anyone?) but once I do I'd like to really tune the ECU to my individual car.
As usual, thanks for all the advice.
Mike
Your advise per the euro cams is spot on. I'm not expecting a huge increase of anything. I'm looking for it to really smooth out the total power curve leading to boost, if anything.
Whereas I'm nowhere in your league regarding car knowledge, the one thing Esprit ownership has taught me is that all things require balance. You can't really just 'upgrade' one thing and expect to get the most out of it.
With regards to the chip, I enjoy Sanj's program very much, but it is my intention to really dyno tune the ECU program for the components I'm running when all is complete. I have a few things engine wise to go (S4s headers anyone?) but once I do I'd like to really tune the ECU to my individual car.
As usual, thanks for all the advice.
Mike
Intercooler -> air cooling
Chargecooler -> water cooling
I've seen info that water cooling is better but must say I'm not fully convinced (Not at speed anyway). I suspect the main reason for it is physical. You could not have an efficient air cooled system on a mid engined car without major ducting. In the Esprit the current ducting is needed just to cool the engine. Water cooling allows the inlet gas to be cooled (rad in reverse) while having the rad at the front to cool the water (cool clean ram air).
Thats my view anyway.
Chargecooler -> water cooling
I've seen info that water cooling is better but must say I'm not fully convinced (Not at speed anyway). I suspect the main reason for it is physical. You could not have an efficient air cooled system on a mid engined car without major ducting. In the Esprit the current ducting is needed just to cool the engine. Water cooling allows the inlet gas to be cooled (rad in reverse) while having the rad at the front to cool the water (cool clean ram air).
Thats my view anyway.
Both air and water are intercoolers. Chargecooler is just the Lotus name for it.
Air intercoolers would have more turbo lag than ours. The pathway for our water intercoolers has less air space and takes a shorter time to come up to boost than an air intercooler.
Both have it's good and bad points, but for our cars with limited room the water works best for us.
Calvin
Air intercoolers would have more turbo lag than ours. The pathway for our water intercoolers has less air space and takes a shorter time to come up to boost than an air intercooler.
Both have it's good and bad points, but for our cars with limited room the water works best for us.
Calvin
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