GRP Intake Shootout Dyno Testing!

seriously said:

When you're full throttle and shifting quickly the intake makes a clear sharp chirping kind of sound. It's great and not there with the OEM filter.

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There are a lot more intake sounds that you can bring out depending on how you use the throttle. It adds another dimension to the drive.

Dragoon said:

There are a lot more intake sounds that you can bring out depending on how you use the throttle. It adds another dimension to the drive.

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Does it fell like the performance has improved?

David s said:

Does it fell like the performance has improved?

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I will need to drive it more to find out. The new sounds are intoxicating enough to distract me from the performance feel.

OK this was totally worth doing! With Aerie Titanium and third Cat delete along with Milltek valve controller and the car sounds like it always should have.!

David s said:

Does it fell like the performance has improved?

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You're never going to feel or measure a performance difference on the car with a +/- of 2-5Bhp on a 400bhp car.
What's the percentage error on a Dyno measurement between runs? Probably larger than these 1% change in values.

I did six dyno runs with my car yesterday.

The difference in power measured between the lowest and highest result was 1.66%

The difference in measured torque between lowest and highest was 2.26%

Oddly the highest measured power run also had the lowest measured torque.

The fifth run was the best overall, with 283kW at the wheels (380hp) and 442Nm.

Steve24 said:

I did six dyno runs with my car yesterday.

The difference in power measured between the lowest and highest result was 1.66%

The difference in measured torque between lowest and highest was 2.26%

Oddly the highest measured power run also had the lowest measured torque.

The fifth run was the best overall, with 283kW at the wheels (380hp) and 442Nm.

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Without changing any hardware?
You're seeing a larger variance on repeated runs than they measured swapping intakes..

Correct, in terms of all runs were the same configuration.

I’ve never dynoed any of my cars before so have no previous experience, but the guys in the shop felt that the run results were very consistent.

I do, however, agree that the only way to know what the value of any mod is is to do back to back runs. The actual numbers don’t matter much.

For example, if I changed something and did another six runs and the results showed a consistent gain that would be good enough for me.

I’ve just had the grp cold air, miltekexhaust and decat. What I noticed was an immediate improvement in throttle response. What I mean by that is that the car pushed effortlessly into the torque range and kept pushing hard to the max rev range. In second gear the car broke traction when accelerating through a curve in the road and needed correcting. I haven’t experienced this before. The dyno may not show much power improvement, but I’ve never put much faith in dyno figures. It’s artificial. Dynos are more useful for when you are tuning certain parameter in the ecu. In the real world, the mods produced a much more improved use of the engine, and it put it quicker into its torque/hp zone. This comes into play when you are driving into and out of curves and corners. My car pulled strongly back into the torque zone when exiting curves and corners. I’ll put it on the track in the next couple of weeks and report back. But from what I’ve experienced on the road so far, it’s a definite improvement. It now feels more like my previous car (410 exige ) in the way it performs out of the exit points of the corners or curves. The “flat spots” have now been eliminated. Well worth it.

The ECU learns and makes adjustments over time. When I installed the Eventuri intake, I drove the car for almost 2 weeks before getting a dyno run. I had already done a baseline run sometime before with the car completely stock, so I had something to compare to. I consistently gained 15+ hp and torque from the Eventuri, and I could most certainly feel it. I did several runs for various mods spread out over months last year, and every single run showed the gain of the Eventuri plus whatever difference the mod made (in one case no practical difference at all). I still have the 3rd cat in place too.

For anyone doing either an Eventuri or GRP intake mod, give it a week or two of driving for the ECU to adapt and adjust, then do a dyno run.

Was there ever a final decision on whether the inventory or GRP intake was better or is close enough?

I see a lot of forum members removing the third cat and adding the GRP filter when fitting a JB4 to their car. Is this only to mirror the specific set up of the test car Burger used to develop the JB4, or because this is a more optimal set up in general?

When reading the results Greg posted in this thread, it appears as though the KNN filter is delivering better HP figures. Why aren't more folks going that route over the GRP filter?

Rupes said:

I see a lot of forum members removing the third cat and adding the GRP filter when fitting a JB4 to their car. Is this only to mirror the specific set up of the test car Burger used to develop the JB4, or because this is a more optimal set up in general?

When reading the results Greg posted in this thread, it appears as though the KNN filter is delivering better HP figures. Why aren't more folks going that route over the GRP filter?

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Likely because of oiled vs a dryflow filter.

Rupes said:

I see a lot of forum members removing the third cat and adding the GRP filter when fitting a JB4 to their car. Is this only to mirror the specific set up of the test car Burger used to develop the JB4, or because this is a more optimal set up in general?

When reading the results Greg posted in this thread, it appears as though the KNN filter is delivering better HP figures. Why aren't more folks going that route over the GRP filter?

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Personally for me it's a combination of replicating results as well as low maintenance of the blue filter like Greg mentioned, no need to oil and getting the saturation amount just right -- and no risk of getting oil on the MAF.

Rupes said:

I see a lot of forum members removing the third cat and adding the GRP filter when fitting a JB4 to their car. Is this only to mirror the specific set up of the test car Burger used to develop the JB4, or because this is a more optimal set up in general?

When reading the results Greg posted in this thread, it appears as though the KNN filter is delivering better HP figures. Why aren't more folks going that route over the GRP filter?

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There's also the concern (which is the primary purpose of the filter) at how good it is at filtering. K&N's aren't as good at that which is why they allow more air through. Unfortunately, they allow more particulate through as well.

If you search on YouTube, there are many tests showing what happens with K&N filters. Here's one link (Project Farm) where he tests different brand air filters, including the K&N:



You can see how much large particle contamination gets through the K&N compared to other filters. They also require oiling which is known to cause problems, and Lotus has stated issues caused by oiled filters will void the warranty.

You're getting an almost negligible improvement in performance at the cost of significantly decreased filtering and increased engine wear/damage.
It seems a no brainer to avoid IMHO.
There's a reason manufacturers have resoundingly stuck with paper filters.

Isn’t the other goal of these intakes to lower resistance on blower and also temps? Especially as boost increases, aren’t those goals good enough to drop $1k?