GRP Intake Shootout Dyno Testing!

[GRP]

This morning we took our shop car to the dyno and did a "shootout" of sorts for various intake and filter options.
Ive made as detailed account of everything as I can below but feel free to ask any questions!

Basic Info -

• Car is Un-tuned, stock ecu.
• Was around 70 degrees when we started and ended at around 78 degrees according to the little weather station on the dyno
• DynoJet Dynamometer --- these are typically the higher reading dynos of the bunch.
• Readings are shown in SAE with smoothing set at 5.
• We are at about 4600 ft of elevation in Reno
• Car has about 2500 miles on the odometer
• Stock Exhaust (including third cat) for all of these dyno runs.
• All runs were done in sport mode except one later run with the Eventuri intake and one later run with the GRP prototype intake done in Track
• All runs were done from approximately 2000 rpms to redline.
• Car automaticlly knows its on a dyno and enters "test mode" which is really nice.
• Car was driven about 15 miles with the stock intake on it to the dyno, we swapped from our prototype intake and exhaust to stock yesterday.

I videoed all of the runs but the sound is totally messed up! I used a wireless lavalier mic near the intake to try and capture the sounds between each and it was a fail. We will be returning to the dyno on or before the 16th with our exhaust and decat installed, I will do my best to capture better video/sound then.

As a base reference point we dyno'd an Evora 400 on the same dyno in similar conditions and it made about 370whp/321 tq. So I was pretty surprised with the results after the very first stock pull on the Emira. I asked the owner a couple times if he was sure that nothing has changed on the dyno since then and he assured me it hasnt but the big bump in power seems excessive.
The dyno was very consistent the entire time and there was only one run where I forgot to hit the sampling button, so almsot every single pull is documented below.

• We did 2 runs on the stock setup -- our stock filter has had the white fuzzy "prefilter" removed fwiw.
• We did 2 runs on the K&N drop in filter within about 10 minutes of the stock runs -- swapping the drop in filters was quick since we left off the engine bay trim pieces.
• We did 2 runs on the Dryflow drop in filter within about 10 minutes of the K&N
• Swapping to the Eventuri was done pretty quickly also since we had run it in the car prior and left it all assembled. Took about 10-15 minutes to swap it out for the stock airbox assembly.
• I was surprised by the results with the Eventuri after the first couple runs, it did pick up power the second run but wasnt what I expected so I tried adjusting the blower fans by aiming one more directly at the intake and one closer up front for the heat exchanger. I also tried disconnecting the battery to see if we could get any sort of a reset on the "learning" aspect of the ecu. It was pretty similar results every run.
• This intake and our prototype were at the biggest disadvantage since we had already done 6 pulls prior and they would be the most affected by heat soak. Also I believe if you install the intake and put some drive cycles/miles on it that it will pick up more power as the short term and long term fuel trims adjust. As a quick bolt on though it didnt show the claimed hp increase right away like I sort of expected it to. . We did a total of 8 runs on the Eventuri trying some various changes to see if it would pick up more power but the second run had the highest HP number. I am unsure what the conditons where during Eventuris intake testing but to replicate it we would likely need to spend a good amount of time on the dyno with more fans etc. They were also probably at sea level or near it whereas we get hurt with our higher elevation. I think @Eagle7 saw the true gains of the intake because of his drive cycles on the car since he swapped at home and not on the dyno like we did.
• We did a total of 4 runs with the GRP prototype intake on the car. 3 of which were sport mode and the last one in track so see if there was any change. The third run showed the biggest HP gain so I am pretty convinced the higher flowing intake kits require some more drive time to show the true results and the subsequent runs past the first couple suffer from some heat soak since the car isnt seeing as much airflow as it would on the road.

Comparison chart below followed by all the individual runs done with each setup. The individual runs also show the "conditions" for each run with temp and humidity.

 

[kitkat]

Wow a lot to digest, thank you for doing all of this Greg!

 

[LuckysDad]

Interesting results.
Especially for the stock setup.
Now we need figures for 3rd Cat Delete and your titanium exhaust.

 

[GRP]

Interesting results.
Especially for the stock setup.
Now we need figures for 3rd Cat Delete and your titanium exhaust.

Scheduled in for the 16th but hoping they have a cancellation sooner.
The weather looks like it will be similar here for the next couple weeks so results shouldnt be skewed much if any by that.

 

[silent cilantro]

MVP Greg doing all this legwork!

 

[benjh1028]

Great stuff Greg!

 

[Eagle7]

A few things that could explain the differences between your results with the Eventuri and mine. I had been driving around a few days with mine installed, before I was able to get a dyno run, so the ECU on my car may have as you suggested, been able to adjust to it accordingly. There's also the possibility that the ECU in your tests wasn't able to properly adjust to the many changes over that short a period of time, which could explain how close the results were. Between the Dryflow and GRP, there's only a 3 hp difference, which considering how restrictive the factory airflow is, I would have thought there would be more of a difference.

Another thing; the dyno the shop has I went to connects directly to the wheel hub, which eliminates any variable with wheels and tires. I notice in your picture that you appear to have one of your wheel sets on the car. Are those lighter or heavier than the factory wheel? What tires were on the car, the Goodyears or Michelin, and what was the tire pressure? My dyno runs showed the actual power to the rear wheels, versus estimated power at the engine.

The difference in altitude could definitely play a part, as you're 2,000 feet higher in elevation than I am.

Whether or not this would make an appreciable difference or not, I wonder if the gold heat reflect foil I put around the intake tube on mine might have had anything to do with the results I got. I obviously had to drive over to the dyno shop to get my run, and he put the car right on the dyno and did the run. We didn't sit around and wait for the car to cool down.

This is a great effort though, and a huge thumbs up for doing this Greg!

 

[seriously]

Wow great work thank you. These things are tricky to account for all the variables. You did a fantastic job trying to isolate and caveat. Bravo

In for 3rd cat delete results!

 

[MIGZ]

Fantastic

 

[GRP]

A few things that could explain the differences between your results with the Eventuri and mine. I had been driving around a few days with mine installed, before I was able to get a dyno run, so the ECU on my car may have as you suggested, been able to adjust to it accordingly. There's also the possibility that the ECU in your tests wasn't able to properly adjust to the many changes over that short a period of time, which could explain how close the results were. Between the Dryflow and GRP, there's only a 3 hp difference, which considering how restrictive the factory airflow is, I would have thought there would be more of a difference.

Another thing; the dyno the shop has I went to connects directly to the wheel hub, which eliminates any variable with wheels and tires. I notice in your picture that you appear to have one of your wheel sets on the car. Are those lighter or heavier than the factory wheel? What tires were on the car, the Goodyears or Michelin, and what was the tire pressure? My dyno runs showed the actual power to the rear wheels, versus estimated power at the engine.

The difference in altitude could definitely play a part, as you're 2,000 feet higher in elevation than I am.

Whether or not this would make an appreciable difference or not, I wonder if the gold heat reflect foil I put around the intake tube on mine might have had anything to do with the results I got. I obviously had to drive over to the dyno shop to get my run, and he put the car right on the dyno and did the run. We didn't sit around and wait for the car to cool down.

This is a great effort though, and a huge thumbs up for doing this Greg!

I do honestly think the Eventuri and our intake will show a bit more power if we put some drive time on them, would it be 20hp as claimed by them? Based on our results today I dont think so, more like 10-15. FWIW our intake kit on the Evora's is a pretty consistent 10hp bump over stock based on numerous tests by Olympic Motorsports in various conditions.

The lighter weight wheels can have an effect on the power delivery vs stock but as long as we have those same wheels/tires on the car for all the testing its all equal in that regard.
This dyno does read wheel horsepower as it sees it at the drum of the dyno. No changes are made to anything from car to car unless its awd. So the dyno doesnt care about the weight of tires or wheels etc, since it isnt calculating any differently from car to car. It makes its calculation based on how it sees the drum being spun.
As long as it is consistent which it was very much so today and we keep the same exact setup on the car we are showing real results at the wheels, although as explained those could change/vary some long term as more drive time is put on the car.
At our next dyno day we plan to basically do the same tests again with our decat and titanium exhaust so we will see if the intakes show similar results. After that we could leave the eventuri or ours on the car, put some drives on it and return for a couple more pulls to see if the theory is true about it getting better over some time.

 

[David s]

A few things that could explain the differences between your results with the Eventuri and mine. I had been driving around a few days with mine installed, before I was able to get a dyno run, so the ECU on my car may have as you suggested, been able to adjust to it accordingly. There's also the possibility that the ECU in your tests wasn't able to properly adjust to the many changes over that short a period of time, which could explain how close the results were. Between the Dryflow and GRP, there's only a 3 hp difference, which considering how restrictive the factory airflow is, I would have thought there would be more of a difference.

Another thing; the dyno the shop has I went to connects directly to the wheel hub, which eliminates any variable with wheels and tires. I notice in your picture that you appear to have one of your wheel sets on the car. Are those lighter or heavier than the factory wheel? What tires were on the car, the Goodyears or Michelin, and what was the tire pressure? My dyno runs showed the actual power to the rear wheels, versus estimated power at the engine.

The difference in altitude could definitely play a part, as you're 2,000 feet higher in elevation than I am.

Whether or not this would make an appreciable difference or not, I wonder if the gold heat reflect foil I put around the intake tube on mine might have had anything to do with the results I got. I obviously had to drive over to the dyno shop to get my run, and he put the car right on the dyno and did the run. We didn't sit around and wait for the car to cool down.

This is a great effort though, and a huge thumbs up for doing this Greg!

I agree. I fitted the GRP dry filter and found a minor "feel" difference. Over the next few weeks, the "feel" has increased quite a lot. It does take some time for the ecu to adjust to the new airflow through the SC. This was confirmed by my Lotus dealer who fitted the filter for me at my last service schedule.

 

[Eagle7]

I do honestly think the Eventuri and our intake will show a bit more power if we put some drive time on them, would it be 20hp as claimed by them? Based on our results today I dont think so, more like 10-15. FWIW our intake kit on the Evora's is a pretty consistent 10hp bump over stock based on numerous tests by Olympic Motorsports in various conditions.

The lighter weight wheels can have an effect on the power delivery vs stock but as long as we have those same wheels/tires on the car for all the testing its all equal in that regard.
This dyno does read wheel horsepower as it sees it at the drum of the dyno. No changes are made to anything from car to car unless its awd. So the dyno doesnt care about the weight of tires or wheels etc, since it isnt calculating any differently from car to car. It makes its calculation based on how it sees the drum being spun.
As long as it is consistent which it was very much so today and we keep the same exact setup on the car we are showing real results at the wheels, although as explained those could change/vary some long term as more drive time is put on the car.
At our next dyno day we plan to basically do the same tests again with our decat and titanium exhaust so we will see if the intakes show similar results. After that we could leave the eventuri or ours on the car, put some drives on it and return for a couple more pulls to see if the theory is true about it getting better over some time.

Oh and one more thing I should have mentioned; my dyno runs were done with the car in Track Mode. I don't know if that made a difference, but I wanted to mention it just to be thorough with the data.

 

[GlobalPilot777]

Thanks @GRP for the great efford! Looking forward for the next dyno runs.

 

[Shahaf2911]

Amazing work GRP! Definitely my go to vendor!

 

[NorCalEmira]

Thanks Greg, this is extremely valuable work! One thing to keep in mind is that a dyno can't fully simulate the conditions of actual driving and it's likely that more cold air would be available to all intakes and filters tested in real world driving. That said, the conditions were the same for all tested configurations and provide a great benchmark.

 

[Lotusdoesit]

In typical GRP style, thorough and detailed. Thank you for sharing these results.

I know your intake is still in prototype stage, but do you have price points yet so we can compare/contrast data between the products and weigh it against price points?

 

[Time2Fly]

Really great work @GRP !

 

[GRP]

In typical GRP style, thorough and detailed. Thank you for sharing these results.

I know your intake is still in prototype stage, but do you have price points yet so we can compare/contrast data between the products and weigh it against price points?

We were waiting to see the results before ordering parts up so now that we know we are hoping to have intakes ready to ship by the end of August.
Target price is around $725

 

[SSJAR]

Thanks @GRP for the testing! Was not sure which filter I was going to go with but just dropped the K&N in the cart along with the license plate bracket kit. Really surprised at the gain from just the air filter. Thanks again!

 

[ATSAaron]

I'm late to this and it might have already been said, but the "jump" at 4000rpm is not from any of the intakes, that is the ECU coming out of closed loop (which is a too lean for best power fuel condition).