Most liked posts in thread: Speed the Lotus Exige

Don’t let the plug and play fool you. What that means is plug it in and play with it for weeks to get it started!
Last time I posted I said I had installed a bace map that got it cranked but was way off. Not only were my AFR’s way off but my dash did not work. One of the Lotus owners in England that has a setup close to my car sent me his map. I only had to change the settings for the injectors and my IAT sensor. My dash and all the gages work, it idles and runs good. I also got the car timed correctly. It seems odd to me to check the timing with the light then have to tell the ECU via the PC how many degrees to adjust. Tomorrow after work I am going to adjust the idle down it’s a little high, about 1600 RPM. I need to get it to 950. Also the AFR’s are slightly lean due to the supercharger I am running. I did drive the car just a little Saturday and data logged the drive. I plan on a longer drive tomorrow to try to get it dialed in better.
I bought a old used PC to do this with but the battery lasted about 45 minutes. So I bought a cheep new small laptop. I spent today after work setting it up and moving everything over to it. It’s battery should last about 8 hours. Much better.
I just hope it does not rain tomorrow

 

Been a while sense I have done an update on the Lotus. The Exige has a dead head fuel system. One of the previous owners put a high pressure fuel pump on it when the SC was added. The stock regulator could not keep up so the fuel pressure was a little high. I decided to add a regulator and a return fuel system. I am going to use a vacuum reference line so I will have a 1 to 1 fuel pressure rise with boost. This means I will have to retune for it. So I decided to add a fuel pressure sensor and data logger. The fuel rail and return line system was straight forward. I was happy to find there was an unused whole in the fire wall just above my fuel pump housing. I ran the return line through it and drilled a whole in the housing to place the return line in.
Pinning into the ECU ended up causing me fits though! First I had trouble finding the right pins. To use the fuel pressure sensor I had to de-pin the traction control(not used) and pin in the sensor and reassign the input in the software. The pin came put easy but I had trouble getting the new pin in. I decided to pull it out and see what was wrong. Well the wire came out but the pin stayed it!!!!! That was pain to get out but I finally did. Late yesterday I got everything pinned in and set in the software. Today I have to pull the fuel rail back off and tighten up one line it has a very small seep. Then I am going to do some clean up to make it look a little better, close the clam and get it back on the road. Once I do the tune I am not doing anything els to the car.


I hope!!

 

Let sleeping baby’s sleep and don’t screw with a Lotus when it is running!!!!!!!

Well I got the car together and took it for a ride. I did not go above 4000 RPMs on the first two rides. I was just checking to make sure my fuel pressure sensor, fuel regulator and data logger worked. All worked great!

knowing all was good (I thought) I took the car out to do same data logs and work on getting the AFRs dialed in. As soon as I got on a two lane highway I nailed it I got to 4500 (where the big cam actives) and bang the car died! Pulled over and it would not crank. I called Hagerty and set up a tow. I was about 7 miles from home. Called my wife who was really not happy with where I was sitting. 1 hour no two so my wife brought the laptop so I could try and find the problem. No dice. Wife is now worried but heads home. 2 hours no tow. Call Hagerty and they set up another tow. Call the wife…….someone is not very happy. I was close to a bad part of town and it would be dark soon. My wife shows up in my truck with a tow rope and tells me she is pulling me home. I get every thing hooked up and she pulls me and the dead Lotus home. That night my wife (she is great) told me forget the computer what would make it stop? fuel or spark I told her. So the next day I found a blown fuse to the injectors. But it blew agin as soon as I hit 4500.

I posted my log from the data logger for the guys on the ECU group to look at. One of the guys saw that my boost went to about 20 psi just before the fuse blew. That can’t be my max boost should be 10 psi. This turned into a month long head scratcher.

First we thought I had a blockage ether in the intake or exhaust. Pulled everything apart, nothing. Then Someone saw my big cam was not engaging that was causing the over boost. Next there were several sensor I tested. Finley one of the guys said it is not reading the cam position sensor. I did a continuity test and found one of the wires was showing open. I had already pulled the plug out of the ECH and pulled on all the wires to make sure they were in place. So I tried agin but this time I moved the locking bar. Well sure enough that one came out. I pushed it all the way in set the lock and just like that it was fixed!

This was the first time I honestly thought I would not get a car running. I am thankful one of the guys caught the sensor reading. The post does not give a true sense of all I looked at. Everyone agreed it had to be with something I touched. One guy even said depin each wire to the ECU and look at them. They are a pain to get to so I just tugged on them. If I had moved the lock I would have found it sooner.

live and learn. I don’t think my wife likes my Lotus anymore. I know one think I am not doing anymore mods! I have been told to leave it alone, I think I will.











P.S. have I told you guys ECU Masters makes a ECU for the R53?

 

Exige.....British for sucker for punishment.

So here is a list of the known Mods

VF supercharger kit
tvs900 SC
quaife LSD
Rota street wheels
Alitexh shifter
Diffuser with aero plates
S111 Dbrace and other upgrades (other upgrades? don't know what that means but that is how it was listed)
Carbon wide scoops
Apr wing
CF Canards
CF front splitter
Boe clam hinge
Engine mount inserts
Baffled oil pan
nitron coilovers
Front adjustable sway bar (unknown brand. I just found out it was there when I looked under the car)
aluminum flywheel
Harness bar and schroth asm harnesses

Things I have done
sonicFURY exhaust
decat pipe
wide band Bosch 4,9 sensor
AFR Wide ban gage
AFR Oil temp Gage
Electronic review mirror
MWR hardend intake cam
MWR upgraded rockers
Bosch EV-14 550 injectors (just installed waiting on the new ECU)

Whats next
Sitting on my bench to install
New IAT sensor
ECU masters EMU Black PNP ECU
Rear tow hook.

They sent me the wrong ECU. The correct one, or I hope it is correct, will be here today.

When the car was delivered one of the coileover perches had fallen during shipping but they was an easy fix. The car ran great. think R53 on steroids. Very visceral and the same insane SC wine (wine what I needed lots two weeks later)

These cars have a problem of cam wipe. So two weeks later I pulled the cam cover and well the cam was wiped!



I talked to owner #2 he couldn't believe it wiped. Some times they never do it but I have heard of it happing in as little as 600 miles. It's odd. This is a Toyota 2ZZ motor. It is in the MR2 and Celica gt among other cars. Lotus is the only one with this problem. There are several theory's on why this happens. Most think it is because the Lotus Elise/Exige have duel oil coolers up front and the oil does not get hot very quickly or not at all. If you get on the second cam (VVT) before the oil is hot you will wipe the cam.

Ok if you made it this far congratulations!

Next post will be on how I fixed the cam and what I did to mitigate the problem.

 

Not much to report. Car is running well but still needs to be dialed in a little more. Between work and the 100 degree days just have not been able to do much. I did run a few logs, they look good so that is encouraging. Last Saturday I took it to a cars and coffee down town.

 

Short explanation why I was mad being the loving brother I am by then he had messed up several cool cars. When my dad let him have it I knew it was a goner. I was hoping I would get to drive it one day.

 

Exige- British for I don’t know why it broke.

Dave you are spot on! So that brings me to what I did to fix the problem. Dave has hit two on the head.

For those that have not seen how the VVT system on a 2ZZ motor works here is a picture of the intake cam and rockers.


As you can see the cam has 2 lobs a high speed (second cam) and low speed. And the rocker has a roller for the low speed lobe and a slipper for the bigger high speed lobe(second cam)

The way it works is it uses the low speed till the RPMs reach 5400 (on my car because the tune lowered the RPM activation) a solenoid open allows oil pressure in to push up on the slipper and now you are using the high speed cam(lobe). Also at the same time oil pressure changes the intake cam timing. Boy howdy can you tell when that cam kicks in.
The cams are oiled by a tube that runs along the top of the valve cover. Here is a picture.


What you can’t see in the picture is the pipe turns down and fits into the head where it gets the oil. The pipe has an o-ring on it for a tight fit into the head.

As I said in the last post there is several theory’s why the cam gets wiped; cam were too soft, not proper oil from the tube, oil temp not hot enough before getting on the second cam. The conventional wisdom is oil temp. I don’t know I think it may be several things. Most people advise you to drive the car till the water temperature comes up to normal working temp then drive another 15 minutes before getting on the second cam. If you have an oil temp gage you want the oil temp over 190f

man this is going to be long, hang with me there will be extra pay if you make it to the end.

So here is what I did to fix the problem.

I bought a harder cam from Monkey Wrench Racing MWR
MWR upgraded rockers. The slipper is wider and harder than stock.
I changed the sandwich plate with one that has a 200 deg thermostat.
@Minidave you are right the car comes sandwich plat with a thermostat to block off the coolers but it never closes
all the way. So it takes for ever for the oil to get hot.
I added an oil temp gage so I would know when my temp was above 190
I blew air through the oil rail in the valve cover and found the holes near the end were getting less air out of them, so I gently opened them up more so the air was the same out of each hole.
Lastly as @Minidave said I started running a zinc additive. Although at the time I did have a cat.

I checked it a month later and it was still good! Yay.

The car was running great. So that October I sighed up for a SCCA track night. Man was it fun.

It was a lot of fun. The Exige is a great track car.

Well all was well till the last stent……..




Well Damn!

Speed hates me!

next post. What just happened.

 

Warning Long post.


After the track day I went about trying to find out why I melted a plug. I borescope my car and other then the melted plug all was good. Some of the more experienced track rats said if the track has a long left hand sweeper it can starve the fuel causing it to go lean, but this track does not have any left sweepers.

I ended up getting a wideband O2 sensor and installing a gage so I could see my AFR. Under wide open throttle they were about where they should be. Cruse speeds were also fine. When I would come to a stop if I did not down shift then the idle would yoyo a few times before smoothing out.

Well I keep researching. I found others who had the same aftermarket SC kit as my car, they had the same problems. The kit is no longer available and the person that did the tunes is noncom. I found out the tuner would tune a very rich AFR to hide knock. The 2ZZ motor is prone to knock. I could not hear knocking but that means nothing.

There is no software to dig into the Toyota ECU that I could find.

I started to think about installing a stand allows ECU so I decided to take some EFI courses to learn more before I decided to replace the ECU with an open unit.

HPacademy had a sale on their online class so I took several of them. They were very good and I learned a ton. I guess enough to be dangerous.

So in these courses they had a good course on knock, what causes it and what can happen if not kept in check. He even said that some times people mistake the effects of knock as a lean condition. Knock disrupts the air/fuel boundary and can cause hot spots. this can cause things to melt like pistons and …….plugs. And as we all know knock is like a hammer on your pistons.

The more I learned about knock the more I have become convinced this is the problem. Also a lot of other things fell into place. For example they covered how race teams try to control heat. If you can control heat it helps to control knock. Adding fuel is one way to control heat. I believe this is also why Lotus put duel oil coolers on the car, to help control heat on the track. These are after all track cars you can drive on the street. Of course too much advance causes knock. There is more to it but I am not the best person to cover the subject.


I bought an ECU Masters ECU Black PNP for the Lotus. No its not exactly PNP. This unit you don't have to mess with the factory harness, just remove the stock ECU and replace it with this unit. My year car has a TMAF so I had to add a AIT post intercooler. The ECU has a onboard MAP, so I also add a reference line to the ECU post intercool. The last thing I did was to add a second wide band O2 and pinned it into the ECU, I no longer have a narrow band O2.


Last Saturday I downloaded a base map and loaded on to the ECU. I needed to go through several checks before starting the car but could not help but hit the start button. It cranked up and idled fine. But my AFR’s were very lean. I spent about 30 long nerve racking min trying to figure it out. I am on a group with some guys in England that have Lotus with the same ECU they were helping a lot.

The original SC is a MP62, my car has a TVS 900. They believe this is why my AFRs were so lean. Another guy with a setup close to mine with a TVS 900 sent me his map to see if that is a better starting point.


When I get home this weekend I will try agin only this time I will take my time and make sure a test everything before I hit the start button.

 

Short update. I have the idle at 975 where it should be so it does not die when I come to a stop. The problem now is it is at around 2 BTDC it should be at 5, idling.
The gas gage showed I was almost empty. When I filled it up it took only 5.6 gal. It’s a 10 gallon tank so the gage is off. I will tackle that later. First address my advance at idle then fine tune my AFR’s. I need to set my fuel pressure also. Then I will correct my fuel gage and make sure my Speedo is correct.

 

I have not solved that yet. I still have to sit down and figure that out. I don’t think it will hurt it but it does need to be addressed.

 

Tiger what a great car! My dad gave my brother a Alpine he flipped it. I was so mad at my brother!