Power delivery issues or is it just me?

[flyingcar16]

Disclaimer: I'm lucky enough to have both a '21 Evora GT and a '24 Emira, so file this post firmly under "first world problems".

I've noticed plenty of differences between the cars - more than I expected - but the biggest downside to the Emira seems to be power delivery. I hope to dyno the car soon but thought it worth asking around, first. Being able to wring it out post break in and oil change, the Emira feels slower than the -16bhp difference would suggest. In addition, the power delivery seems inconsistent between pulls, between gears, and has hiccups across the rev range, with a slight but noticeable VTEC-like boost at 6000 rpm. It feels constricted, though that doesn't explain the above inconsistencies. I feel no such issues in the GT by comparison. It could be issues that are unusual or specific to this car but I thought I'd air it here, first, to see if any other owners feel the same or have thoughts about possible causes.

 

[Racer X]

I have no issues with smoothness, but I do have the “on cam feel from 6-7k rpm. The engine feels like it could keep producing good power over 7k, shame the limit hits right there.

 

[LuckysDad]

I feel there is a lack of low end torque for sure. 3rd cat delete and Eventuri's Intake helped with that.
Going to add titanium exhaust at some point.
I definitely feel that surge of power higher in the rpms as well.

 

[ADC]

Power delivery is not scheduled until Q3 for the US market.

Interesting that you say this though, as I have found mine started to feel less urgent as I got the the 1K mile mark (doing an oil change tomorrow) ... which makes no sense in my head. Others are observing good things from an air intake/filter swap and 3rd cat delete, if that is inside your comfort zone.

 

[Eagle7]

The stock air filter has a thick gauze pad on the back which to my mind has to be fairly restrictive to airflow. Obviously it needs to filter out anything coming in through the side of the car, which is its main purpose, but after installing the Eventuri, I immediately noticed the improvement. The engine starts, idles and accelerates much more smoothly now.

I got a stock baseline dyno last week, and I'm scheduled for another dyno run tomorrow, so I'll post up the results in my journal thread "Adding Lightness" tomorrow. I've done nothing else to the car except add the Eventuri, so this will show exactly what it adds to the car.

 

[tnbuilder]

The stock air filter has a thick gauze pad on the back which to my mind has to be fairly restrictive to airflow. Obviously it needs to filter out anything coming in through the side of the car, which is its main purpose, but after installing the Eventuri, I immediately noticed the improvement. The engine starts, idles and accelerates much more smoothly now.

I got a stock baseline dyno last week, and I'm scheduled for another dyno run tomorrow, so I'll post up the results in my journal thread "Adding Lightness" tomorrow. I've done nothing else to the car except add the Eventuri, so this will show exactly what it adds to the car.

Looking forward to your update. I am curious at what point a tune is needed. Is an Eventuri and 3cd still safe for the car, at some point, unless it can correct itself, it will run lean.

 

[Kimmax]

unless it can correct itself

Definitely can and does. You can watch fuel trims via OBD.

 

[kitkat]

The stock air filter has a thick gauze pad on the back which to my mind has to be fairly restrictive to airflow. Obviously it needs to filter out anything coming in through the side of the car, which is its main purpose, but after installing the Eventuri, I immediately noticed the improvement. The engine starts, idles and accelerates much more smoothly now.

I got a stock baseline dyno last week, and I'm scheduled for another dyno run tomorrow, so I'll post up the results in my journal thread "Adding Lightness" tomorrow. I've done nothing else to the car except add the Eventuri, so this will show exactly what it adds to the car.

Hey the thick gauze pad, is that just a charcoal filter? I think US cars are required to have them, they absorb gas fumes. Pretty sure this can be removed from the car as the euro cars probably don't have them. I don't even see this part in the service manual -- it can likely be removed from the USDM car and improve sound / response etc.

 

[David s]

I know what you mean. That flat spot getting oof the line was really annoying. My car was completely transformed since the 3rd cat delete, and high flow air filter (from GRP was fitted). Don`t judge the car till you do this.

 

[tnbuilder]

I know what you mean. That flat spot getting oof the line was really annoying. My car was completely transformed since the 3rd cat delete, and high flow air filter (from GRP was fitted). Don`t judge the car till you do this.

Wonder how the Eventuri compares to just the high flow filter?

 

[Eagle7]

Hey the thick gauze pad, is that just a charcoal filter? I think US cars are required to have them, they absorb gas fumes. Pretty sure this can be removed from the car as the euro cars probably don't have them. I don't even see this part in the service manual -- it can likely be removed from the USDM car and improve sound / response etc.

It doesn't look like a charcoal filter. It might be to stop bigger things like leaves, bugs, dirty water or things kicked up by the front tires, etc. but it has to have an effect on airflow.

 

[Eagle7]

Wonder how the Eventuri compares to just the high flow filter?

The Eventuri is a straight flow-through design. No hard turns or sharp corners. The inside of their silicone connecting tube is also smooth inside. The factory airbox, even with a less restrictive air filter element, does not provide a straight path for airflow. Here it is from the top. The arrow at the bottom is where the air comes in from the side of the car. The thick section in the middle with the short arrow is where the air filter sits, and the gauze side is facing the intake hole. After the air leaves the filter, it has to make a hard right to left turn to go past the MAF which is in that rectangular slot at the top. (You remove it and put it in the Eventuri when installing the Eventuri).

After the air exits the filter box, it goes into the silicone tube that connects the box to the supercharger. The inside of this tube is a series of grooved ridges which the air chops and bumps over as it makes another left turn through the tube into the supercharger.

The Eventuri is a straight, smooth flow-through design; no ridges or bumps inside. Here you can see it from the end where the silicone tube connects it to the supercharger. The air comes straight out of the filter and into the tube without having to make any turns. The 2 silver bolts at the top is where you put the MAF sensor, which sticks down into the airflow.

So it does more than just improve airflow through the filter element, it channels and directs airflow all the way through it from entry to exit into the supercharger.

 

[tnbuilder]

^^ Thank you for the detailed explanation.

 

[scc.131.fe]

@flyingcar16 Usually when I feel any inconsistencies I notice the traction control light flashing at me. Sport on Goodyears with 900 miles done. It's pretty easy, even in Tour, to get some slip in 2nd gear in straightline dry-road acceleration. But that light is not very noticeable when you aren't looking for it. Could you be experiencing some intervention that just feels like inconsistent engine response?

 

[David s]

Wonder how the Eventuri compares to just the high flow filter?

Don’t know. But I can say that for $79, the power increase and throttle response was quite surprising. If the eventuri is significantly better that that, then I’m in with u.

 

[flyingcar16]

I'm encouraged by some of the reports, here. I just visited a local dyno shop today where I'll take both cars for a baseline once the heatwave breaks. It sounds like air flow may be a big bottleneck and the Eventuri sounds intriguing. I may start with that and then see whether cat delete and ECU changes are needed.

@Eagle7 - I'd be super interested to see your dyno results. Even if the conditions are somewhat incomparable it'd still be interesting. I'll plan to share my results for the two cars as well.

I'll add - the dyno shop asked me to look into whether the car has a "dyno mode". That's probably been answered elsewhere but figured since I'm posting...

 

[Hell4Leather]

It doesn't look like a charcoal filter. It might be to stop bigger things like leaves, bugs, dirty water or things kicked up by the front tires, etc. but it has to have an effect on airflow.

View attachment 47462

How do you remove the gauze? It appears to be part of the air filter. Do you need to just replace the entire filter? Does Lotus require the use of only their bespoke air filters for this reason?

 

[CHEESE]

I haven't noticed any hiccups in power delivery. It's been very smooth and the throttle and torque are super responsive.

 

[kitkat]

I tried without the "gauze". It made no difference to sound or power than I could notice, it's pretty much just loosely glued onto the OEM filter.

 

[Hell4Leather]

I tried without the "gauze". It made no difference to sound or power than I could notice, it's pretty much just loosely glued onto the OEM filter.

Read in the other posts that the gauze could potentially help keep moisture out of the intake/MAP. That seems reasonable.