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Yet Another Turbo Upgrade Project


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Hi All;

I am in the middle of engineering yet another turbo upgrade. In order to try and optimize a solution I would really like to know at what inlet air temperature (IAT) does the Lotus high torque ECU begin taking corrective action with the timing? It would seem to me if, I could (using intercoolers) and correct turbo selection, run 14 # of boost and stay out of timing retard that would be a great goal. A home run would be knowing what the IAT vs timing retard curve looked like!

Marcus have any thoughts.

Wayne

The Older I get the Faster I was

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Hi Wayne,

Yes the ECU takes the MAT/IAT into account and adjusts for ignition, fuelling and if the MAT/IAT is too high also the boost gets reduced.

IMHO a very good upgrade is to use slightly bigger (not too big ones !) reflowed turbos. This will give more flow at higher boost and also will lower the MAT/IAT.

Addditional intercoolers will add to the benefit, but up to 450+ HP its not a must, IMHO. Of course it will not hurt, besides the well known downsides: slightly more lag, pressure drop, not original appearance, lot of work to install ...

My personal favourite is the following:

- K&N filters

- Red race ECU

- reflowed turbos + Alu-actuators (max boost 1 bar)

- better primary injectors (I personally love the RCs)

- high flow cats or if your country allows it: De-Cat pipes

- high flow exhaust system

With a setup like this you can get reliable 450+ HP easily and moreso your engine bay will look perfectly original :blush:

I know of one V8 owner who did 500 Hp with the very same setup at slightly higher boost around 1,1 bar on a very cold day on the dyno. Not too bad ...

Marcus

Edited by Bibs
REMOVED QUOTE - MARCUS, I'M GOING TO REMOVE YOUR ABILITY TO QUOTE POSTS!

Marcus

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What kind of rad are you going to put up front? I am doing a intercooler kit on my car and I'm not to happy with the rad that I got shipped with my kit so I'm looking for some new ideas. if anyone has any good recomendations let me know. I had some make mention of using the air conditioning rads for intercooling but I'm not sure if I want to live with out air. Then again I don't use it much but it still would be nice to see what other people have done. Pictures would be great. and sorry Wayne for getting a little off topic but I just had to ask.

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Hi folks,

On page 6 of the following thread, you can see an image of my charge-cooler rad.

Rebuilt thread

This is a custom radiator fabricated using a motorsport water-air heat exchanger core. I would recommend using a similar rad. that has the biggest area and is subjected to decent air-flow to maximise efficiency.

Cheers,

Mike S

1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

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Hi Steve;

I don't know about the radiator sizing yet. I need to know the IAT, which below, the ECU takes no intervening action (That's my goal IAT). Say it's 135 degrees F. If the selected turbo outputs 231 degrees at say 238 CFM, then I need to disapate 103 degrees at whatever BTU rate comes from 238 CFM per intercooler. Spearco claims the 2-200 core can drop 99 degrees with an inlet temp of 275 to 176 with source water temp of 130 degreee F at 270 CFM & 15PSI of pressure. The trick is to calculate the radiator size to maintain water temp of 130 degrees on exit of the radiator with the BTU loading from dropping the intercooler temp by 103 degrees (2X).

Anybody else remember there thermal calculations, it's been a real long time!

The Older I get the Faster I was

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I plan on using to IAT's at some point after the build to see what kind of drop we get... but, to me, the physics can only be so accurate... there are too many other little factors to get a truly accurate Temperature drop... and then there's the real-world pressure drop as well... so, if you lose 99 degrees but you lose 4 psi... that's not very helpful..

Modifying esprit's.. now that's fun..

PS... I AM NOT A CERTIFIED MECHANIC.. I Have chosen to help those in need, in the past and must not be construed as being a certified technician.

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Mark;

Math actually does work reasonably, one must not overlook all the variables. BTW the Spearco core is a plate & beam construction with an internal pressure drop of 0.25# at the values I quoted earlier.

The Older I get the Faster I was

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Those are some very good pressure drop numbers.... Perhaps it was a bit bold of me to make that statement.. I tend to play devils advocate, sometimes too much... sorry.

Modifying esprit's.. now that's fun..

PS... I AM NOT A CERTIFIED MECHANIC.. I Have chosen to help those in need, in the past and must not be construed as being a certified technician.

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The fuel injection cut off per the manual is excess of 14.5 # for greater than 2 seconds, but people who play with higher boost levels with the stock ECU claim they have not seem it?

I have not been able to locate informatiom on the boost vs IAT vs timing curve. I have been told less than 158 degrees F. "things should be fine"?

The Older I get the Faster I was

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  • 2 weeks later...

I have reduced my turbo boost control choices to either Marcus's RED ECU or my existing High Torque ECU with a modified external boost controller and Marcus's wastegate control capsules. I have looked at the 4 major add-on electronic boost controllers and I beleive I can configure/modify one to add in "Lotus like" safeguards. The goal is 0.9 bar of sustained boost in either case. Living in California with smog testing every 2 years is a problem when using the RED ECU.

I need AFR information from any owners which may be using Marcus's RED ECU or the High Torque ECU at 0.9 bar of boost. Marcus's has provided some information on his ECU, but I have only "street myths" for the High Torque ECU. Information on either ECU in this application would really help with this decision.

I have my Edelbrock datalogger & Inovate wideband O2 sensors I can borrow from the race car to test the results in the Esprit when I get this installed. I will publish the data when done.

Thanks,

Wayne

The Older I get the Faster I was

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  • 4 months later...

The mock up of the left side intercooler showing compressor duct routing. The "string" is the back wall of the new trunk. I will have to give up the "bump out" for carrying the flat rear tire!

The clutch slave cylinder will have to be rotated 180 degrees to move the line away from the duct.

The mock up of the right side intercooler showing compressor duct routing.

The right side duct routing

Both the left & right side ducts are being fabricated from scratch with some minor flow improvements

The Bell Intercooler core with the laser cut & CNC break press bent parts. The parts were laid up using the Solid Works program.

The intercooler core and parts ready for welding, with some minor grinding & the AN-8 bung for the water lines.

Another view.

Hopefully by next week I will have all the the assemblies back ready for installation. I still have to design a support structure for the intercoolers and find a place for the BOV's. The radiator header tank will have to be replaced, reshaped to fit in space alloted and a intercooler header tank also needs fabricated.

The Older I get the Faster I was

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Glad to see it coming together man! :)

Modifying esprit's.. now that's fun..

PS... I AM NOT A CERTIFIED MECHANIC.. I Have chosen to help those in need, in the past and must not be construed as being a certified technician.

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Nice work Wayne!

Any chance you could repost the images at 800 * 600, in accordance with this thread and particularly post no 16? Once you do I'll strip the old ones out for you.

http://www.lotusespritforum.com/forums/ind...p?showtopic=474

Looking forward to seeing your next step on the car.

Regards

Mat

post-1-0302470001278592957.jpg

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  • 1 month later...

It has been a slow program, but commng together. You can see the clutch slave cylinder rotated 180 degrees, to allow up pipe to clear, and can almost see the heater hose outlets converted to AN fittings with 30 degree hose ends to "turn down" the hoses to clear the intercoolers.

Here you can see a wooden shelf underneath the intercoolers (a prototype) to support the intercoolers, which will also bolt to the heads using the original up pipe bolt holes. The in/out water water lines are clearly shown. The string represents the new "end of trunk" line. I have a stainless flex pipe on order to replace the EGR incotel pipe.

I will also require a new header tank to be made as the stock one won't fit in the space available. This shows a foam filter mock up of the right size. Fabricating the left side up pipe has been the biggest challange, there is just no room! A small swril/header tank for the intercoolers wil go on the left side, same location.

Edited by WEllison

The Older I get the Faster I was

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Looking Great Man!!! Nice to see the progress!

Modifying esprit's.. now that's fun..

PS... I AM NOT A CERTIFIED MECHANIC.. I Have chosen to help those in need, in the past and must not be construed as being a certified technician.

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Good progress Wayne.

Isn

1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

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Great eye Mike!

A fabricator error, he put the IAT in the location of one of the BOV's! It's been moved to the output side of the intercooler on the bottom. BOV's can't go on untill I break the tack welds off the intercooler cores too close to drill the 1.25 hole size. Everything's back to the fabricator for final weld up.

The engine on the dyno is the 2nd one we've produced. It had a 2 minute initial firing. I just today finished the programming cycle to accomplish the 30 minute burn it run. The Froude dyno is a Eddy current dyno and I can fully program RPM and load. The new motor has the same intercooler as the one's I picked for the Lotus. The first motor was not intercooled. I have instrumentation to look at both in/out temp and pressures on the intercooler. I should be able to flow bench my intercoolers next week. I will get pictures of the fabricated left side up pipe, we were able to get a bigger cross sectional area than Lotus did, using thin wall aluminim tubing also helped, but boy do I have the hours in the up pipes!

Wayne

The Older I get the Faster I was

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Good stuff. Seemed too obvious an oversight for someone who knows what they

1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

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  • 2 weeks later...

The intercoolers and piping are almost finished. The up pipes need to have the turbo line mounting tabs installed and then be ceramic coated. I have decided to shelf the project for now as I want to drive the car over the summer. This project streched out a bit. I still need to fabricate the replacement header tank to fit in the smaller space, install the intercooler header tank, and route the intercooler coolant lines. The braided stainless line will be the new EGR line to the exhaust manifold.

The intercoolers & up pipes in place.

A comparison view of the stock ducts and the new intercoolers and ducting

Edited by WEllison

The Older I get the Faster I was

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Excellent stuff - Well done on getting this far.

Enjoy the car over the Summer and finish it off later in the year.

Cheers,

Mike S

1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

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