Intercooler Project Finally Finished

[WEllison]

Over a year ago I started on this intercooler project with two goals directing the project. (1) I would do nothing which would prevent me from returning the car to completely stock. (2) An intercooler system capable of supporting 450 RWHP, 0.98 bar of sustained boost, at road speed of 55 mph, while keeping the ECU from taking any defensive measures like dumping boost or retarding timing. With a lot of information from Lotus, Spearco Turbonetics, Bell Intercooler, Garrett Turbochargers and C&R Racing Radiators I think I have made it. Preliminary testing shows that the IAT runs about 2 *F below ambient, however I have not had it on the track to get some sustained testing data. The ECT runs right on the thermostat temperature of 82* C and I do not get temperature creep while idling. I have yet to have the fans come on, but the hotest day so far has been 80 *F.

The finished Intercoolers in place without the new boot insert.

The cores along with the assembly parts which were laid out in Soild Works, cut on a laser cutter and bent up with a CNC brake. I am considering making the intercooler assemblies if there is any interest in them.

Here's a comparison of the stock up pipes and the fabricated replacement ducts, before adding the turbo oil line mounting tabs.

Two pictures of the finished up pipes with all oil line mounting tabs and heat wrap

These are the fixtures required to locate the mounting tabs, the flanges to mount the intercoolers to the heads and get the angles correct for the new flex stainless EGR pipe.

The source lines to the intercooler and the single return line from the intercooler header tank routing by the transmission. The heat wrap is in the turbo area.

The source water line "Y" attached near the firewall. I used the new Gates power grip heat shrink clamps throughout.

The intercooler lines go forward in hard lines outside of the backbone. I was concerned about heat coupling from the water & oil lines in the backbone. The trick was to attach them without drilling holes in the backbone.

Here's a comparision of the OEM radiator to the new radiator. I designed the new radiator to eliminate the steel frame to obtain maximum space for the radiator thickness. This radiator will support 450 RWHP and the additional 51,000 BTU per hour from the intercooler radiator while at full boost. The new radiator with Spal fans weigh 11 pounds less than the OEM.

The intercooler radiator was a real challenge. To get the required BTU dissipation with low static pressure drop and get it to fit in the "stack".

The engine radiator back view. The radiator has anti-reverasl flaps to prevent drawing air from behind the radiator while stopped or at low speeds with the fans running. I can get both these radiators built at a very reasonable cost if I build them in lots of 5. The engine radiator with the Spal fans is less expensive than anyting else on the market and are very high quality build using CAD fabrication.

The "stack" with all three heat exchangers mounted.

I mounted the Spearco 7 GPM pump on the the front cross beam away from the engine heat and down low as it needs to flood for priming. This pump has an 18,000 hours life span.

The routing of the two hard lines for the intercooler heat exchanger in the stack. This was a real squeeze.

The stack ready to lift into the car, complete with oil coolers.

I had to fabricate a new boot floor as the intercoolers took up the semi-circle space in the OEM one. I made a plug from the OEM unit.

The completed new boot floor with a paper pattern for the dress plate.

I hope to have more data as a result of testing soon. I am just happy to have this complex project done!

Edited May 14, 2010 by WEllison

[mike_sekinger]

Absolutely fantastic Wayne!

The findings about the effiency of your systems are to me, equally as exciting as the layout and design.

Cheers,

Mike S

[WEllison]

Thanks for the good words Mike. I am looking forward to getting some real good test data.

Wayne

[neal]

Superb - very professional job!

What have you done to get that boost from the ECM? Obviously it's easy enough to get that boost by setting it mechanically but I've always been very nervous about that solution. It only allows the ECM to retard the igntion or adjust the fuelling, but not reduce the boost, even if the knock sensor indicates the pistons are detonating to destruction. Plus the Lotus ECM will start dumping fuel like crazy since it doesn't know about your lovely intercoolers.

I know Mike used a fully programmable Motec controller for his GT1 replica which allowed completely flexibility (e.g. a 3 bar MAP sensor would be very useful to detect spikes or a failed wastegate which would go unnoticed with the stock 2 bar one that simply maxes out). But I understand the cost of that was horrendous, not only the actual controller but also the time required to set up all the mappings, etc.

Edited May 14, 2010 by neal

[WEllison]

Hi Neal,

I didn't mean to mislead anybody I am not yet producting 0.98 BAR of boost that was my design goal that the intercoolers would have to deal with. I am currently running the Hi Torque ECU and after I am convienced the IAT is locked down, I will set about re-mapping various tables in the spare ECU, I have commimg. EFI did provide the software to program their MT-501 ECU on which the Lotus ECU is based and I have a copy of that software. Unfortunately I don't have the templates for the Lotus specific (quite different)ECU so I next have to figure those out. I want to retain all the Lotus designed in protections just increase the boost and correct the AFR.

Wayne

[t70]

Nice work Wayne!!! Fabulous!!!

[trackmagic]

Wayne,

Congrats on getting to the end of the tunnel. This reminds me of my project and the countless hours. What the hell was I thinking! At least I was lucky on the intercooler part.

Best,

Jeff

[lotus4s]

Really nice work Wayne, very impressive!

[WEllison]

Thanks everyone for your kinds words, it was a lot of work. I am anxious to see how it performs.

Wayne

[Tony94S4]

work of art Wayne,

can't wait for datalogs,

on the heat exchanger for the air coolers

do u have a pic with different angle for the

end tanks?

they look small in the pic,

I am sure they calculated the floow thru them

[WEllison]

Tony,

The size of the end tanks for the intercooler heat exchanger are not a critical item. The tanks only need to distribute the water to the tubes. The tanks can provide a reserve cooling function, but only until the system reaches a temperature equelibrium. The heat exchanger was sized to provide the correct BTU dispation to support continous full boost. (about 51,000 BTU per hour) I should have test data soon.

Wayne

[WEllison]

I have now put 400 miles on my Esprit with the new intercoolers and radiators. I have recorded about 350 miles of data. All of the miles have been on the street so it does not contained any long term sustained boost data.

1. IAT under cruise operation runs 3-5 *F. BELOW ambient temperature at typical road speeds. I am seeing 80 to 90 * F. IAT on 85 * F. days.

2. The higest IAT I recorded was at WOT under full boost for about 15 seconds in 4th and 5th gears where the IAT reached 104 * F.

3. I recorded a maximum wastegate duty cycle of 60.5% (the highest so far while on the street) with a MAP of 49.7 in/hg. Barometric pressure was 29,6 in/hg, yielding 20.1 in/hg (or 0.680 bar) of boost.

4. One section of the 400 miles was a return from San Francisco in heavy traffic. The ECT did reach 100* C in stop & go traffic, but when the fans came on the ECT dropped very quickly to 82 * C. (thermostat temperatue) which is where the ECT runs with any reasonable road speed.

On September 28th I will have the car at the Thunderhill race track for more testing.

So far I am very pleased with the results.

[WEllison]

sheet1.pdfsheet2.pdfChart1.pdfChart2.pdf

I waited for a very hot day and went intercooler testing. The entire run was 60 minutes (3731 seconds) sheet 1 and chart 1 are a subset of the entire run and sheet 2 chart 2 are a subset of sheet1. Barometric pressure was 26.75 IN/HG at my altitude. I was able to acheive 24.74 IN/HG boost 12.156 PSI (High Torque ECU) after running the car for 40 minutes at an ambient temperature of 106 * F. I am very pleased.

Wayne

[hyteck9]

I can't believe this thread just....  ends?   This is fantastic work and I would think lots of people would be putting in orders.  Is there more to the story I do not know?

 

Did you ever produce additional units for sale?

[greentengu]

Wow--you and me both, Brian! I only have an '86, but this is a fascinating thread, that ended upwards of four years ago. What happened to all this meticulous research? Where did all that hard work and amazing fabrication end up? What's up with the car? And yeah--whatever happened to the idea of a group buy of those absolutely fabulous one-off radiators with the Spal fan package (not that it would necessarily fit my car, but still...)?

 

Cheers,

 

Scott

[swindon_alan]

On 14/05/2010 at 23:22, WEllison said:

Hi Neal,

I didn't mean to mislead anybody I am not yet producting 0.98 BAR of boost that was my design goal that the intercoolers would have to deal with. I am currently running the Hi Torque ECU and after I am convienced the IAT is locked down, I will set about re-mapping various tables in the spare ECU, I have commimg. EFI did provide the software to program their MT-501 ECU on which the Lotus ECU is based and I have a copy of that software. Unfortunately I don't have the templates for the Lotus specific (quite different)ECU so I next have to figure those out. I want to retain all the Lotus designed in protections just increase the boost and correct the AFR.

Wayne

@WEllison Hello Wayne, I hope that you are well and still lurking!

I'm doing some due diligence on a generally available low cost replacement for the V8 EFI ECM and it would be a great help if I could have a copy of the MT-501 programming software if you still have it?

Thanks in advance

Alan