cammmy

Is 100 octane leaded? Another thought could be the carbon cannister. Try blanking the port (at the front of the manifold, near the firewall) just to see if that helps.

Yeah, that's fair enough. It's always good to have a choice.

I might be stating the obvious here but ethanol was introduced for emissions reasons, not to save us money. It's produced by growing things so the carbon released by burning it comes from the atmosphere, not underground. It has it's upside though, ethanol is less energy dense but it has higher octane and a lower stoich ratio than petrol. That means you can run more compression/boost without detonation as well as burning much more of it per combustion cycle. As you say, worse economy but you can get significant power gains out of it. Personally, I wish they would sell E85. I would happily change out my lines and add a flex fuel sensor to be able to run that.

I've been replacing my belt every two years because I thought that was the interval. Is it actually 3? I've been using the "Steve's alternative" from SJ.

I can recommend Rapid Mechanical Services in Romford if you need a Lotus specialist: https://www.facebook.com/rapidmechanicalservicesltd/

The tank vents through the cannister, which catches the fumes. There's a solenoid on top of the cannister which connects to a pipe that runs to the manifold. Under certain conditions (manifold vacuum and certain RPM range), the solenoid opens. Manifold vacuum pulls air through the charcoal and brings the vapours into the engine to be burned. Under boost, the solenoid is closed but there is also a check valve in the pipe near the manifold to stop boost getting to the cannister. When pulling vapour from the cannister, this will cause the mixture to become more rich. I'm not sure if there is anything specific in the code to pull fuel or whether it just relies on the O2 sensor but If something is not right here, it could be messing with your fueling. You could cap it temporarily to see if it changes the behaviour. It could be that if your solenoid isn't opening, the cannister is saturated and allowing fumes through. Unfortunately, I don't know enough about the system to say for certain which conditions cause which symptoms other than it sounds like your engine may be stalling because it's going lean.

Have you had a look at your charcoal cannister? They open/close under specific circumstances and could potentially cause issues if not behaving as expected. If the problem comes back, you could try capping it to test. From memory it's connected into the timing belt end of the little manifold that's used to get a MAP reading.

Glad you seem to have fixed it but I didn't think the GT3 had a throttle jack? We don't have a valve in the exhaust and the idle is handled by the idle control valve.

I may be selling my five-0 injectors soon, if you do go down that route, let me know. They have about 5k miles on them. I'm aiming for ~400hp, so will be going with bigger primaries and secondaries.

No problem. One thing to mention, I haven't heard the Alunox manifold but it imagine it's quite a different sound. I believe it has equal length headers whereas mine are very much unequal, giving it the boxer sound. I don't doubt the Alunox is a better performer though.

This is a custom manifold, free flowing mid-pipe and Hayward and Scott backbox (And the BOV insert has since been changed, that's just the one it came with... don't judge me) Same car onboard, various mods between the two vids but the exhaust is the same. One thing I would say about the H&W backbox, the welds were cracked on it when I got the car and it was completely stock back then.

In general, when pressing the throttle causes hesitation or the car to die, it indicates that it's running lean. So either it's not adding the fuel that it should or there's an air leak. I believe air leaks are more likely to cause the issue on cars using AFM rather than MAP though.

I went with an MS3/X with 4 bar MAP sensor: https://www.diyautotune.com/product/megasquirt-iii-ems-system-with-ms3x-expansion-v3-57-assembled/ (Though I used a DIY kit.) When it comes to choosing an ECU, first, find a tuner you trust and then see what they will tune with. You can easily lose any savings you make on an ECU in tuning time because it takes them longer, or the only people who work with that ECU are more expensive. That happened to me. This was before I upgraded the turbo:

Thanks but unfortunately, I learned that lesson myself with the hub. He thinks they can weld it back together though. They are an expert classic car outfit, he gets flown around europe to support their customers vintage race cars. It's always awesome visiting their shop.

Okay cool, I'm working on a different car at the moment but I'll try pull that down soon. Mine was tuned on a hub dyno.

Sorry, I meant I bought a generic bearing/seal driver kit but was asking if this special tool is an absolute must. Great, thanks. I'll get in thouch once I have all my supension components back. The old bushes are pretty well stuck in place, so they are at a friend's workshop to be pressed out.

I'm about to do a similar thing as I'm doing a full suspension refresh have a slow leak past the seals. I bought a bearing/seal driver kit to do the job, is it a case of slow and steady should work or is this tool really needed? If someone was willing to loan, I would be happy to provide a 100% deposit and pay the postage.

Personally, I would never consider something as drastic as a turbo upgrade without either standalone management or a flash tune developed for the specific combination you are running. These cars only have a narrowband o2 sensor and the readings are ignored at WOT anyway, so you really are chancing it (not to mention ignition timing requirements). I went full standalone on my GT3 and I highly recommend it. I now have wideband o2 in addition to all of the other advantages. I got 280bhp on the stock turbo and then 290 with vernier pulleys (though I lost a little at the bottom end for that) I now run a GTX2863R which does have a higher boost threshold than the stock turbo but is much more capable. I'm at 320bhp as my injectors are at the max duty cycle I'm comfortable with. The turbo should do around 400 but I want tougher transmission internals and an engine refresh before I explore that.

I have a dyno tuned 920, though I can't remember if I pulled the latest map to the laptop or not. I could post that if you're interested? It's not a stock engine though. Full exhaust incl. manifold, vernier pullies, GTX2863R turbo.

Okay cool. My cooling system works fine but I am running a bigger turbo and 320bhp. If it's just a flow issue then I'll try turning it to hot but leaving the fan off and see, once my suspension is back together and road legal.

My advice is to use the aerotight nuts everywhere on the exhaust. I haven't lost a stud yet but I've lost several turbo to manifold bolts. The other advantage of aerotight style is that they can be had with a smaller hex size than normal, making them much easier to fit. I used stainless on the turbo bolts last time but they still corroded quite quickly, so went to titanium.

Does the carby engine have boost retard or is the base timing set for full boost with only vac advance? If there is a boost retard feature, you absolutely want that. For vac advance I can't see why not having it would remove oil from the bores. The only detriment I can think of is reduced economy and more heat in the exhaust valves/turbo. For the latter I can't imagine it would even approach the temps seen under full load, so doubt it's an issue. Though I will note, when you really load things up, retarded timing is safer for detonation but it's still not good for the engine, for the reasons mentioned above.

So with the stock setup, is it better to run with the heater set to hot or cold?

You have to ask why that was done though, It's quite possible that solenoid is faulty. You do want it working though as the wastegate spring will probably be something like 7psi. Normally the solenoid bleeds the signal to the wastegate so that it will run at the max boost in the tune, which could be 12-14psi. Then there's the overboost, which is a temporary increase Above that normal max.

I've had the cracked manifold and it definitely didn't sound like that. It starts as a ticking and gets louder as the car warms up and the metal expands.