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Looks ACE Stefan, happy for you you're getting nice results, it's really a 1 of a kind car :whistle:

Going strong that is !

On the first possible occasion, me wanne see this beast :P ...

Thanks Hans, the day will come :sick:

Good stuff. You

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Just turned 2? Awesome work for a toddler

Can 'we' see the car in Wiesbaden/Giessen this weekend ??

Stefan, it wasn't meant -as for 'posing' power competitions ! those guys just understand more if you talking 'fuel talks' as your wife or neighbours... . So it is allways good to compare experien

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why couldn't you find bigger injectors?

I found a set of

Lucas 48lb

4/Set $225.00

2.5Ohm

and a set of

Siemens 3102 55#

(575cc/min. at 3 bar,

43.5 psi.) -

Low resistance: 2.5 Ohms

$312.50

also found many different sizes of secondary injectors from 200cc/min-300cc or higher

Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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Travis

These are very large injectors.

Wonder how they work ?

I based my search on the fact that now I have 370s for primaries and 270 for secondaries.

This would put me somewhere in the 400 to 450 range, but there is nothing available.

Stefan

Mind if I cut in ?

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with 4 stock primaries at 370cc/min and 2 secondaries at 270cc/min, you only have 8.6% more fuel, at the stock fuel pressure.

With increased fuel pressure, you'll of course get more, but how much? Did you have the injectors flow tested at higher pressure?

If you are still going for 500hp... you'll need alot more than 8% more fuel!

Given stock injector duty cycles (and timings) you'd need 5 (assuming 4x primaries and 2 smaller secondaries averaged) 575cc/min injectors for ~360hp.

http://www.rceng.com/technical.aspx

For 450hp, you'd need even more...

Though going with larger primaries can lead to poor low throttle running conditions, so many go with larger secondaries... But you'd need some big secondaries for 450-500 hp

A guy named Burt Waite in Arizona got his Esprit SE up over 600hp (many mods), but had to have 10fuel injectors with 2 fuel computers...

Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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Not very technically minded I'm afraid but recall that my old RS500 had two injectors per cylinder is it not worth looking at this as an alternative. Smaller injector better control maybe!!

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If I were looking to achieve 500bhp then I'd probably use Siemens Deka 55 lb/hr primaries which are good for 300 bhp at 80% dutycycle and then a couple of Lucas 75 lb/hr for the secondary injectors which should do the extra 200 bhp at 80% dutycycle. The Siemens would hopefully have good enough low rpm control and atomisation so as to not make drivability an issue.

Now whether you can fire the secondary injectors at less than 4800 rpm and 0.7 bar is down to the programming/mapping of the ecu.

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Ok, here is a short update on my findings :D

Went to the RC website and calculated a potential injector, based on their sheets.

Problem is that RC is not addressing secondaries in their calculations.

I ended up with a main injector of 1068 cc !! That does not look realistic, does it.

One can operate 2 ways. A : larger injectors and B : higher fuel pressure.

In both cases it is the amount of fuel that counts, to not lean out the engine at higher RPMs with higher boost.

The Sport 300 programe, for instance has a stock fuel pressure of 4.4 bar over the standard S4(s) of 3.2 bar.

I run my 2.6l on 1.2 to 1.3 bar of boost as the default setting with a option of 1.6 bar over boost.

My newly installed fuel pressure guage is yet set at 4.8 bar with the injection time increased by 20%

I am still on my old 370 / 270 cc injectors.

My conclusion is that if one uses bigger injectors, the fuel pressure must be lowered and vice versa.

After all I guess I am doing ok with where we have gone, unfortunately we can't do much testing at the moment as the CO problem in the cooling system is not solved yet.

Cheers

Stefan

Edited by Fandango

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Hi.

I have strugglet a lot with the stock ecu earlier.

And had 4 extra injectors with 2 fuelpumps to be able to get enough fuel at high boost/rpm.But this didnt solve the problem.And went trough 3 headgasked because the stock timing was to high and got smal deto that cased light headgasked failure so I got high pressure/temp in the cooling system.

I gess this is the reason for your cooling problems.You also need to use the old termostat with early opening.I gess with your headgasked system solved It can take a lot before the headgasked fails completly.

I did put a aftermarked (am) Autronic SM4 ECU on it to solved a lot of problems.It runs much better,with higer output better milage,Headgasked last much longer now on high boost.Using 1000cc injectors.Modern am ecu use a reverse pulse to close the injector to be able to get a precise fuel delivery at ligher load and idle. But It will not be better than the man who tunes it.

The stock ecu is good for a stock engine but very limited on a higly modifyed engine like yours and you will be way better of with a aftermarked ecu.If I was living closer I could have helped you with putting a aftermarked ECU and programmed it to work.

Edited by rydning

89 Lotus Esprit Turbo S

Very fast road and trackday car.

GT3076R+ a lot of other modifications.

http://lotusespritwo...inZzdningz.html

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Rydning

Thanks for your input and information.

The reason why we stayed with the stock ecu was excactly what you just mentioned.

We would have gone from blank in programming it. Mind you that at Lotus there are many engineers who have come up with the programming of it.

Besides, it would have called for a new and different wiring harness as well.

Being just a garage, it is very hard and time consuming to do the same.

I will forward your comments to Steffen who will probably very much appreciate them to determine our further steps.

Stefan

Edited by Fandango

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If putting on a complete aftermarked ECU,will also recuire custom triggersystem,coil setup and so on,since its nothing of the modern systems that will work with the old lotus enging management system.

What do you use to tune the fuel?

I use a Inovate Wideband lamda.I tune the fuel so the AF is 12,5 on racefuel I can use around AF13.

But using stock timing you might need to go for a ritcher mixure because you are not able to tune the timing, and use AF 11-11,5,i dont recomend using any more fuel because it will wash down the cylinder walls for oil and cause to little lubrications.

What fuel pump do you use? You gona need a Borsch 044 pump,or stock + a extra pump to be able to get enough fuel for 500bhp.

I would have put bigger extra injectors so the lamda reads between AF11-12 if possible.

You can also put on extra injectors managed by a Haltec extra fuel ecu or so.Witch is very easy to use.

You can use the stock ecu to manage 1 of the extra injectors,and the Haltec to run the other.

Putting bigger injectors like 500-1000cc in both places.You can probably use the 4 stock injectors with slighly higher fuel pressure.But you gona need way bigger where the 2 extra injectors are...remember stock is 264hp and you are going for 500bhp,,that will almost recuire 100% more fuel delivery.

Its also several other ways to tune this engine with stock ecu.But I feel you will be better of with a extrafuel injector management.

Edited by rydning

89 Lotus Esprit Turbo S

Very fast road and trackday car.

GT3076R+ a lot of other modifications.

http://lotusespritwo...inZzdningz.html

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I had Markus at PUK remap the injection time and increase it by 20 %

We also use wide band Lambda to measure the AF, we are shooting for the same setting 12 to 13.

So far the reading is good, it is just in higher RPMs and with a boost above 1.3

Remember I got now a 2.6 l engine with a closed deck and the same turbo you have.

That alone already increases the HP, I guess we just need to find a way to make sure it does not go lean

The engine runs very smooth and we have not noticed any knocking. This is also a reason why we are so puzzled about the situation.

Don't know the make of my new fuel pump, will have to ask R & B

I will forward this post to Steffen, lets see what he says.

Thanks again Rydnik

Stefan

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You might have to put a fuelgauge to look on while driving to see if it holds the pressure,if not you need a bigger fuelpump.If you run 3,0bar non vacum fuel pressure the fuel pressure should be 4,3bar @1,3boost and 4,[email protected],5boost and so on...I gess your turbo is pretty much maxed out at 1,4 bar with your modifyed 2,6ltr engine.Anything above 1,4 bar will mostly give hotair and little hp gain.Mine is maxed at 1,5 and able to use 1,7 with racefuel and a lot of advanced timing (gives less backpressure because more burns inside the engine).

What rpm do you get full boost (1,3bar)?

89 Lotus Esprit Turbo S

Very fast road and trackday car.

GT3076R+ a lot of other modifications.

http://lotusespritwo...inZzdningz.html

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Travis

These are very large injectors.

Wonder how they work ?

I based my search on the fact that now I have 370s for primaries and 270 for secondaries.

This would put me somewhere in the 400 to 450 range, but there is nothing available.

Stefan

euh Stefan, don't they have bigger ones @ RC ? Thought they have them even +550 ! Or do they not fit ?

- Nulla tenaci invia est via -

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You might have to put a fuelgauge to look on while driving to see if it holds the pressure,if not you need a bigger fuelpump.If you run 3,0bar non vacum fuel pressure the fuel pressure should be 4,3bar @1,3boost and 4,[email protected],5boost and so on...I gess your turbo is pretty much maxed out at 1,4 bar with your modifyed 2,6ltr engine.Anything above 1,4 bar will mostly give hotair and little hp gain.Mine is maxed at 1,5 and able to use 1,7 with racefuel and a lot of advanced timing (gives less backpressure because more burns inside the engine).

What rpm do you get full boost (1,3bar)?

Rydning

I will have a complete summary for you later on today or tomorrow

euh Stefan, don't they have bigger ones @ RC ? Thought they have them even +550 ! Or do they not fit ?

Hans

RC has much bigger injectors in their flightline, but Steffen is not sure if they are appropriate as we have installed a bigger fuel pressure guage.

Hopefully he has some info for us today.

Edited by Fandango

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Rydning

We reach the set 1.3 bar max boost at 3200 rpm.

Mike

This is the device we are using to get performance readings.

My car has not been measured as we want to solve the CO problem yet.

Steffen has performed a pressure test of all cylinders and there is no leakage.

We tend to lean towards installing a new cooling system with larger radiators.

http://www.alpin-tuningshop.de/index.php/en/reiner-3000

Stefan

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Hallo Stefan,

With the performance tool. I assume you have to enter vehicle weight, air resistance and rolling resistance for it to calculate the power (at the wheels) correctly. Just out of interest, what values did you use for your tests?

I was thinking about adding this facility to my V8 scan tool, but when I saw that the calculation formula had this data I gave up, as apart from the vehicle weight I have no idea what the real air resistance & rolling resistance is on the varies V8 esprits.

Gruss/Regards,

Peter.

Edited by peter_england99
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Peter

tomorrow I will scan my old sport 300 readout and post it.

Will have to see myself what we put in back then.

You can ways email r&b and have steffen explain it in detail.

Stefan

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"We reach the set 1.3 bar max boost at 3200 rpm."

You should get that boost before 3000rpm with the mods you have on your engine.

My 2,2 with the same turbo and AR 0,82 turbine gets 1,5 at 3500rpm..

I think you should beginn saving for a aftermarced ECU,to bad that your very good modifyed engine is resticted by the stock ecu.just my toughts..

89 Lotus Esprit Turbo S

Very fast road and trackday car.

GT3076R+ a lot of other modifications.

http://lotusespritwo...inZzdningz.html

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Car resistance on the road: [N]

rolling resistance + air resistance + roadangle resistance + acceleration resistance (+ an car/device to pull behind the car)

rolling resistance:

fR x car mass (under gravity) x cos (of road angle)

air resistance:

0.5 x 1.2 kg/m^3 (for the air) x cw (body shape factor..) x square area of the car [m^2] x v^2 (vehicle speed)[m/s]

roadangle resistance:

car mass (under gravity) x sin (of road angle)

acceleration resistance:

Lambda ( factor to specify all rotating mass in the drivetrain, depends on gearspecification and so on..) x car mass (under gravity) x acceleration/gravity [a/g ,as an factor]

For the calculation of different types of wheels you can use:

( with Mitschke calculation)

fR= fR0x (1+0.5x([v/v0]+([v/v0]^4)) )

*fR0* is to calculate as 0.01 (for more simple calculations..)

*v* is actual speed to what the calculation should be

*v0* is the maximum speed for what the tire is made

Peter, I hope i could help you out on this. What i not know for sure is the *cw* factor of an Esprit and its square dimension (the factory can tell you more on this..)

quick note:

all this is to calculate the power on the wheels.

in [N] , if you want it in [W] multiply with the speed [m/s]

and for engine performance that is needed calculate the drivetrain (or in other words 'engine') effectivity

something like 0.8 would be good . You know that the pure effectifity of an compustion engine (for itself..) is also not 100%

Edited by G

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the formula posted is the pure mathematical theory from the university.

On an dyno you will mostly simulate the load on the wheels with parameters and the *magnetic brake* will act as an driving resistance.

The university formula is to determine the exact power that is needed to perform in the physics world. You can find that in every engineering scriptum from nearly all university's -it is common standard of education..

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to name the things if I see them, that's what I call integrity..

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i can try to calculate the power manually for, lets say 200km/h on an evenly road.

What should i do on the wheels(lets say all are made for an top-speed of 290km/h) ..hmm, and the A (square dimension) is 2m^2

not right exact, bud as fast as possible:

185.98 N for rolling-road resistance (wheels)

plus

1333.4 N for the force of air

is around 1519. 4 N on an steady run -no acceleration, no tilting road, nothing to pull behind (trailer or so..)

Esprit with 1380kg weight

-> means 84410 W ??? -I really hate mathematics.... .

Edited by G

*********************************************************************

to name the things if I see them, that's what I call integrity..

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88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

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