Retrofitting a chargecooler

[rogerch]

We know what it's called Roger, the problem is I think we are all struggling to understand how "the entire chassis starts to distort when I lay it down hard" running only 0.8 bar, when a virtually identical S4S & V8 twin turbo etc chassis seems to cope with huge amounts of extra power and torque fine.

It's the first time I've ever heard someone say that their chassis distorts when they put their foot down....

You're obviously not trying hard enough. In truth it's really only detectable exiting high speed turns, carrying throttle, keeping the wastegate closed and the boost up, and getting all the power down with no wheel spin.

Read up on the history of the Lotus 30 & 40, I think it was Chapman's own admission they were the worst 2 race cars he ever built. Both used a backbone chassis, and flexed. It was a major problem for Doc Bundy with the Esprit. The roll cage was as much to stiffen the chassis as it was for  safety.

Now I want you check your setup, tyres etc, go out there, plenty of good roads in Wales (choose a dry day) focus on exit speed, don't loose boost pressure, keep the throttles open, pressure up to at least 6, and accelerate as hard as you can without loosing traction. You may need to left foot brake, even drag the brake on exit rather than lift of, your an ex rally guy you do all this stuff, get into it hard.

I'm a believer in set up, I don't like surprises or guess work, I like to know what will happen next, spearing off into the scenery is not on the agenda.

Edited June 12, 2014 by Roger the Dodger

[Mike6]

When I last saw Pete Musgrove of Lotus company PNM he had fitted a chargecooler set up on his carb turbo. I was interested in doing the same but as I had removed my aircon rad he said it wouldnt be possible as the rad is sacrificed for the chargecooler set up. Have a word with Pete if you are thinking of converting - I think he sells the parts 

[Simon350S]

You're obviously not trying hard enough.

Clearly Roger, you are right there.

It ain't made it out of the garage for a good 8 years except to a failed marriage ceremony.....

Need to try harder!

[chris]

The boost limiter and pressure sender are in the Off Side rear quarter panel.  I thought about removing it totally but as I wanted to keep the original boost gauge I simply removed the earth connection on the top of the unit so that the vacum system is still intact but the limiter no longer has an effect.

I then fitted an electronic boost controller which not only allows me to set various levels but also includes a fail to safe system effectively replacing the limiter function.

I have fitted the controller above the stereo but you can house it in a more discreet location if you don't want it on display.

Currently my car is at PNM Eng having the chargecooler fitted, decided that i would pay someone to do the plumbing side of things plus pete has all the parts to make it a tidy install such as SE cam cover, mounting plates and bushes, plus he will be able to set it up properly with bigger main jets. Have had issues in the past with rolling road tuners who say they know carbs but dont really.

I like your idea of mounting the radiator at the rear but would be a little concerned with the lack of air flow and the heat soak generated from the engine.  I think "changes" was looking at modding the engine under tray to direct more airflow but I dont know how far he got with it.

My rational was to get the system installed as a carb setup as pete say's he's had great results from it and when the engine required a rebuild I was thinking about upgrading it to a 300 spec with an aftermarket fuel injection system but I will see how the carbs work out first as I am a little sentimental over them ( I know, its sad!).

[Corban]

This is good information, thank you Chris. This boost controller, where can I get get one? I have been looking on the internet but it is always good to get a make someone have tried with good results. I e-mailed Pete some days ago, but no reply yet. Knowing myself, I must have all parts needed before I start, so I can do the mods in one swoop, otherwise the risk is that the car will be standing unfinished for a long while. Please keep us updated here on how the chargecooler installation comes along and how the change feels.

[red vtec]

All interesting stuff,

Don't you need to change the pistons to the SE type as they have a coating to deal with the higher temp.

I did look at charge cooling but decided it's to much hassle for the gain, I'm looking at switching to EFI instead on my car. But even then I might just look at making sure the carbs are in good service and setup. In reality a turbo is more than quick enough for the real world.

I'll look at the pnm setup. I'm rebuilding mine at the mo.

[Corban]

I have been thinking about SE pistons and the chrome coating to endure higher temp. My thoughts were that the fuel injection gave too precise a mixture with all the sensors and stuff, thus creating more heat. Looking at fuel consumption, my milage with a carb fitted engine is never below 10.5 litres per 100km (don't know mpg) but I understand the SE can easily achieve 9.0 litres per 100km AND give more power. The carbs are jetted to give a rich mixture in order to cool the pistons and combustion chambers. If, as mentioned in the post above, the main jets are changed to give more fuel I think you can pull it off without changing the pistons but at the price of higher consumption. But when and if I rebuild the engine, I would also go for the 300 spec. If you're going to do it, you might as well do it right

@red vtec: I agree that most of the time the standard 210bhp is more than enough. 97% of the time I drive my Esprit like a normal car on the road and on track it is cornering that is the fun part. Just break less and it goes faster :-) Lap times may be suffering from less acceleration into the straights but I can live with that. But here is the thing (for me anyway), when the kids in their BMW:s and "fast and furious" cars see the Esprit on the road (from afar) they speed up to come closer and then they start tailgating (they fill my rear view mirror). I usually ignore them for a while and then floor it exiting a roundabout or similar situation. THEN it would be nice to see them shrink in the mirror to the size of a stamp. With 210bhp they don't The Esprit looks like a supercar (in fact I think it is) then it should MOVE like a supercar. The design, both G and S cars is way ahead of its time and the cars look really fast. Few people think my MY88 is that old

[chris]

PNM's car still runs all of the original engine internals, hence I wasn't going to change anything until forced into a rebuild. Suppose it really depends upon how much power you want to run.  I believe there's a chap on here (project thread) who has upgraded his esprit to 500bhp!!! 

The boost controller I use is a greddy unit which i got off of ebay.

[Corban]

Yes! that is a cool project. I have read that thread. Car is now up for sale on mobile.de. 50 000 euro roughly which probably is a bargain if you consider the amount spent on the rebuild. I will check out the greddy unit.

[Corban]

Hello Esprit lovers I couldn't wait for all the parts before I got started. Since I had to change the clutch master cylinder anyway and thus putting the car to rest for a while (the interior was scratched so my new gaskets weren't enough, had to order a new cylinder) I might as well use the downtime to start the operation. I intended to post some pictures but they need to be resized so they will come tomorrow (I hope). As I started to take the parts apart I discovered more and more issues. No 1, there is a linkage to the choke that is made out of steel wire. This will interfere with the secondary injector part of the inlet nozzle (picture to come).No 2, There is a hose that gives the plenum pressure to the carbs, a very short hose. This outlet was missing from new nozzle, how to fix? drill a new hole? and fit a pipe to it? Well, I did what I could at the moment and changed the cam cover, naturally the old oil filler cap does not fit the new cover, but a new has been ordered, used some tin-foil for the time being. This way I could position the chargecooler to start to take measurements for the rear and front mounting. This was the hard part, taking 3D positions in thin air, almost without reference. I managed to make some CAD-files to have them manufactured and now I am waiting for these parts. I did not manage to figure out how the front mount was designed so I decided to design my own (think it is integrated to the injection rack which I lack) It will be like a though jubilee clip that fits around the oil filler neck (picture to come). to be continued... (with pictures) getting late here in Sweden and I am getting sleepy

[Simon350S]

Suggestion for you....

Dump the secondary injectors and nozzle, you're not using injection anyway.

Cut down your existing turbo pipe and fettle it to fit a silicone hose from the chargecooler.

By doing this you retain the pressurizing pipe work to the carbs with minimal effort and have no need to find a way to block up the secondary injector holes as there won't be any!

Job done!

[Corban]

I didn't want to take away the secondary injector part from the nozzle with my angle grinder because I might reuse it further down the road and I want it to be original.

in this pic you can see the choke linkage which will interfere but the fuel hose will not because it is closer to carbs. The "bump" starts further out. The oil filler cap is also visible and would end up under the chargecooler if not changed. Also visible is the mount for the throttle wire.

maybe a better picture.

The linkage I cut and extended with a small tube made of brass, moving the lowest part down 25mm so it runs clear of the nozzle underside. This included some rebending of the old shape.

Here is the "new" cam cover in place and so is the inlet nozzle (you can see the bump on the underside). This cover has no holes for the throttle wire mount. These I drilled and threaded in the new cover. I also changed the holes in the mount to make it low enough to fit under the chargecooler.

Chargecooler in place in order to take measurements for the front and rear mounts (this was the really tricky part). They are still in the workshop but this is how the 3D CAD files look.

I hope I measured right...

This is what it looks like today:

In order to solve the problem with pressure feedback to the carbs I used the sensor hole in the chargecooler to fit one of the secondary injection connections and a hose to the carbs, partly visible in the picture above but maybe better seen in this:

here you can see the new oil filler cap.

The front and rear mountings are to be lazer cut and welded by a friend of mine. So far I have been dealing with the "getting rid of heat from inlet air" part but soon comes the "getting rid of heat from the water" part. I have extracted from my old Saab 9000 the heater coil to the compartment and the cooling coil from the AC. The one for the coupe is very small and I doubt that it is sufficient, but maybe the AC unit will do it. Problem is it is smaller on the intake side thus creating a worse pressure drop. Maybe I can change this with my dremmel. By the way, new clutch master cylinder fitted and bled and working perfectly :-) 

to be continued...

 

 

[Corban]

@simon350s, that was my first thought but since I have a nozzle that is from the SE and I want to have the possibility to reverse the  modification this was not an option in the end (hurts my soul to even think about putting the angle grinder to the original nozzle)

[Corban]

HELP! Smoke coming from the engine bay. Havn't been running the engine for some weeks now and today I decided it was time to test the new clutch cylinder and see if my solution to the "pressure to the carbs" problem worked. I fitted the heat shield between turbo and engine and started her up. No problem there but after a short while I saw traces of smoke coming from the left hand side of the engine. Coolant OK and oil OK (checked before start up). Turned it off after checking temp and oil pressure. Temp= halfway to normal and oilp. ok. Smoke kept coming and it had increased some. No exhaust fumes then since engine was off. Next thought, could there be oil on the exhaust manifold and/or the part from it to the turbo? I let all things cool down then I used a degreaser and some water to wash the manifold and the part to turbo. I tightened the nuts that hold the heat shield if they in some way seals the far end of the camshaft cover (anyone know if this is the case?), thinking maybe oil is leaking from there. I Let it all dry and started her up again. Same thing! Smoke defenitely is coming from below exhaust cam cover somewhere. Lifting the car and using mirrors I tried to find out where but no luck. Did the cleaning all over again but still smoke. No change in sound so I don't think the manifold has cracked. Any ideas anyone? As far as I can see none of the mods for the chargecooler could have this effect except for maybe the bolts and nuts for the heat shield.

[Bibs]

Cam covers leaking is a very common Esprit complaint. Remove, regasket, replace. Job done

 

If the gaskets are leaking, the oil would have been soaking into your manifold rust for a while now and that's what is burning off now as the manifold heats up. 

[Corban]

Thank you Bibs, I'll have a look at this asap.

[Corban]

Time for an update

 

Been scouting for a suitable radiator to put at the "get rid of heat" side of my chargecooler installation but finally I gave up and ordered an aluminium one + a small header tank. They arrived today. Eager to get the Esprit on the road again I threw myself at the task of mounting the items mentioned above. Since I have no clue to how my positioning of the radiator will work (possible heat soak from engine etc). I strapped it in with cable ties behind the rear valance. Some hose cutting and jubilee clip adjusting later (actually it took me 4 hours to get it secured and in place) it was time for a test run after filling and bleeding the system.

I drove her gently at first, to get the temperature up to working level, expecting Murphy and his laws to leap out from behind some corner and punch me in the face but he stayed out of sight (fingers crossed). After a while everything still seemed hunkydory so there was no excuse to wait any longer to floor it. The road was clear from traffic and I put the pedal to the plastic in second gear.

I will not go so far as to say it blew me away but the feeling was that something had changed to the better. It felt like it started to pull earlier (more torque), couldn't really notice the 3000rpm glitch as before. Did this test a couple of times in second and third and the feeling was the same every time. Since I don't have a proper benchmark to compare with I couldn't rule out the psychological factor but it felt faster. Then I remembered that I had memorized the reading of the boost gauge before the install when I was considering an electronic boost controller. I think service notes say it will reach 0.63 Bar and to reach this before the install I really had to drive it hard. So I did some more test runs, flooring it in second, third and forth gear and had no trouble getting the gauge up to 0.7 Bar. I decided it was not entirely in my head

 

After the ride I put my hand on the chargecooler as this, I am told, is an indicator to how it is working. It wasn't hot at all. It was not cold but no problem putting the hand on and keeping it there (kind of luke warm). The old pipe you couldn't touch for 30 minutes.

Satisfied with this test run, I think I will make some nice brackets to replace the cable ties, look at some 200mm fans that will fit the radiator (think this can lower temp. further) and order an electronic boost controller and see what that will add to performance.

 

To sum it up, it was not the kick you would get out of an SE, my estimate is that I gained around 15-20 bhp. Hopefully a boost controller will allow me to override the 0.71 Bar limiter with maintained security and find them missing ponies (maybe 25 of them).

[jonwat]

Some pictures would be nice :-)

[Corban]

Here are some pics:

 

This is the header tank, not too big

 

Radiator in place, this is now protected by a mesh

 

What you see from the outside

 

Two things I've noticed, temp stays lower at normal driving. Instead of reaching 80 degrees C rather quickly it levels out at 70-75 degrees. Driving a little harder it goes up to 80. Reaching a boost level (according to the gauge) of slightly more than 0.7 Bar and staying there (this was a long uphill in fifth gear) is easily achieved. I am still not sure how much more power I have gained. It feels a little quicker but I am nowhere near the 265 bhp of an SE. The chargecooler and rad feels luke warm after driving, not hot in anyway so heat soak from engine seem not to be a big problem. How does a factory fitted chargecooler feel after some hard driving?

 

Next step I think is an electronic boost controller. How much do I dare to tweak it? Anyone here with experience from this kind of device?

[jonwat]

Very nice, looks a tidy job. 

 

Have you considered water injection? PUK Esprit do a kit.

 

 

Injection Kit € 790,–

 

 

Water/Alcohol Injection Kit IV with ECU.

- This Kit is specially designed for the Lotus Esprit 4-Cylinder and V8 cars

- Kit contains: Very High pressure pump 14 bar/ 200 PSI

- Special Removable Water/Alcohol Helix Injector (is a combination of a spiral + venturi jet that gives much more atomization than any other injector/jet design !!!)

- NEW VC-25 adjustable ECU unit (see pic below right side). Fully boost dependable mapped water injection supply (no switch like ON/OFF triggering !)

- Operation LED that indicates when the system is operating

- One way valve for water supply from reservoir to pump (its not really necessary but will help to start the pump sucking when not been in use for longer times ;o)

- All necessary hoses, fittings, cables and mounting material

- Injector size is 175 ml/min for 4-Cyl. application OR 2x100-125ml/min for V8

- injector thread size is 1/4" NPT

- All tubing is 6mm/0.25" diameter 

Click to enlarge

Click to enlarge

 

[Corban]

Thank you John

 

Havn't been looking at water injection. Is the purpose to lower inlet air temperature even more?

I looked at the PUK web page but I can't find anything about expected gain, how much is this supposed to give?

First hand experience could be interesting.

 

[jonwat]

  Is the purpose to lower inlet air temperature even more?

Yes if you inject water, more power if you inject alcohol :-)

I'm afraid I don't have experience of it myself, would be fun to try though :-)

[Qavion]

How does a factory fitted chargecooler feel after some hard driving?

 

 

How long after you stopped did you check the temperature? Mine is usually cool (especially after I fitted an electric pump), but soon heats up after stopping.

[Corban]

Roughly 1 minute, stop engine, open up bonnet, removing and placing engine cover against garage wall. It is not hot, I can put my hand on it, my guess 30-35 degrees C. Received my electronic boost controller yesterday. Hopefully I can install it this weekend. Any suggestions on how to best route the electrical wiring from rear to binnacle?

[Corban]

Help, advice and experience wanted!

 

I have now fitted an electronic boost controller. I haven't managed to set it to show Bar instead of PSI so I have to do some converting between test runs. Program A is set up to give 0.65 Bar (set to 9 PSI) as the standard factory setting. Program B was set to give 0.85Bar (12PSI) as the SE gives in short periods but I had to reduce this to 10PSI because it was kind of brutal and I want to go easy on the car and not blow it up (not on the first run anyway )

I am interested in knowing how much boost others have increased their cars to, please feel free to share and if other mods have been made to cope with this.

Another worry is that it may run lean when I push more air into it but then I thought the fuel pressure regulator might compensate. The spring in it adds 0.29Bar to boost, so if I increase boost, I increase fuel pressure which should deliver more fuel to the carbs. If this relation is linear I don't know. Any thoughts on this?

 

Installing the chargecooler and the boost controller has really improved performance considerably already at this stage and I think there is more to get when I have tweaked the boost settings.