[KingLT1]

As I mentioned way back in this thread when it was created in 2018, you can not accurately measure gains with CAI or Ram air stuff on a dyno. The air box does not get the same pressurization on a dyno as it does at high speed on the street or track. The Rotofab was tested at the track against a modified stock airbox w/ green filter and the test car still went quicker and faster in worse DA. That was a Bolt-on SS car.

Back in the 4th gen LS1 hey day's Chris 1313 developed a ram air system for the F body. it showed very little power gain on the dyno. However at the track guys were picking up 2+ mph in trap speed.

The testing needs to be done at the track/street. Send me a Vararam and Ill test it against my Big Gulp RF with a Dragy. I have a good spot to test. I will log data and confirm that the tune isn't skewed. I will also make sure the MAT are similar before doing any testing. No BS unbiased testing will be made. I am all for higher performing products and if the Vararam proves to be that much better I will switch.

[Z OH 6]

Originally Posted by KingLT1

As I mentioned way back in this thread when it was created in 2018, you can not accurately measure gains with CAI or Ram air stuff on a dyno. The air box does not get the same pressurization on a dyno as it does at high speed on the street or track. The Rotofab was tested at the track against a modified stock airbox w/ green filter and the test car still went quicker and faster in worse DA. That was a Bolt-on SS car.

Back in the 4th gen LS1 hey day's Chris 1313 developed a ram air system for the F body. it showed very little power gain on the dyno. However at the track guys were picking up 2+ mph in trap speed.

The testing needs to be done at the track/street. Send me a Vararam and Ill test it against my Big Gulp RF with a Dragy. I have a good spot to test. I will log data and confirm that the tune isn't skewed. I will also make sure the MAT are similar before doing any testing. No BS unbiased testing will be made. I am all for higher performing products and if the Vararam proves to be that much better I will switch.

This would be a good volunteer for the bet. I just need a few more.

[EDFHOBBIES]

We used my car for street pulls i was all stock at the time He data logged it all the oem box was pulling 5 degrees knock he got it down to zero. And total timing increased 2 degrees the maf was close to 1000 mv and lowerd to 800s. This 2 years ago but it's all in his threads the data and all.

I to was a skeptical but I saw the results so did Sorian. It worked well on my car but the testing on England's Greens dyno on a totally stock A10 were good aswell but many pulls later the filter that made the most power always reverted to a different table.

So I agree snake oil on a non tune car they don't do much in the long run of the car will just use another safe table.

[FoundNemo]

Originally Posted by EDFHOBBIES

Here is where we tested on a stock 2018 zl1 A10 against the 2 major companies. Like mentioned on a stock car if the parameters were to much the tune reverts back to a different table.

But on a tuned car like mine we able to pick up over 35 hp over the rotofab for instance mine was tuned on the rotofab we added the prototype and picked that power.

This is the only pic Patrick wanted me to share.

Extremely interested in the Vararam when its ready. I'll leave the Rotofab for the masses lol

[ZX-10R]

Green filter with snow blocker removed. Cheap.

[CamOnlyJabroni]

Originally Posted by Z OH 6

This would be a good volunteer for the bet. I just need a few more.

Well King is my brother so we can put it on my ZL1 too. I just put on a CAI Carbon Elite so we could use all three in the comparison.

[Z OH 6]

Originally Posted by CamOnlyJabroni

Well King is my brother so we can put it on my ZL1 too. I just put on a CAI Carbon Elite so we could use all three in the comparison.

Works for me.

[FoundNemo]

Originally Posted by ZX-10R

Green filter with snow blocker removed. Cheap.

Snow blocker is off alrdy agreed

[LT4Greg]

If the Roto-Fab CAI is not good then why do all the aftermarket companies that have parts for our cars use and recommend them in their builds? I wish someone would answer that for me. Any answers guys?

[hawk02]

Originally Posted by ZX-10R

Green filter with snow blocker removed. Cheap.

Best low cost mod for the ZL1.

According to Vararam, the stock air box with a high flow filter like the Green and the snow blocker removed will outperform most after market cold air intakes in real world testing.

See the second to last paragraph

https://www.camaro6.com/forums/showt...003&page=9#122

[Joshinator99]

Originally Posted by KingLT1

As I mentioned way back in this thread when it was created in 2018, you can not accurately measure gains with CAI or Ram air stuff on a dyno. The air box does not get the same pressurization on a dyno as it does at high speed on the street or track. The Rotofab was tested at the track against a modified stock airbox w/ green filter and the test car still went quicker and faster in worse DA. That was a Bolt-on SS car.

Back in the 4th gen LS1 hey day's Chris 1313 developed a ram air system for the F body. it showed very little power gain on the dyno. However at the track guys were picking up 2+ mph in trap speed.

The testing needs to be done at the track/street. Send me a Vararam and Ill test it against my Big Gulp RF with a Dragy. I have a good spot to test. I will log data and confirm that the tune isn't skewed. I will also make sure the MAT are similar before doing any testing. No BS unbiased testing will be made. I am all for higher performing products and if the Vararam proves to be that much better I will switch.

This is what is needed! Someone who has no financial gain to be had, and more importantly, someone who knows what they’re doing and will call it right down the middle.

[FoundNemo]

Originally Posted by LT4Greg

If the Roto-Fab CAI is not good then why do all the aftermarket companies that have parts for our cars use and recommend them in their builds? I wish someone would answer that for me. Any answers guys?

The rotofab will flow more with the hood up so when you dyno it, unrealistic gains are shown due to the airflow increase. EDFHOBBIES is spot on about this and its totally logical.

However, once you close the hood it effectively chokes off the filter on the top so its a false "gain" artificially inflated on the dyno. My buddy and I did back to back dyno testing on his car in Georgia with a Rotofab and the hood up, rotofab with hood down and the OEM airbox with the snow ingestion cover removed. All of the runs had the snow ingestion cover removed fyi.

Most people say when you get to speed it doesnt matter but it does, because total flow is not just the key aspect for intakes.

You also need to consider that power from air intakes is affected by all of the following:

- Laminar air flow across the MAF sensor (for MAF equipped cars) vs turbulence across the MAF sensors which can heavily impact power levels and driveability based on poor quality airflow readings (regardless of total cfm), which impacts how the car adjusts spark. Link: https://www.counterman.com/understan...r-flow-issues/

- Overall intake air temperature and the source of the air feed (turbulence, volume, temperature, etc)

- Rates of heat soak based on the material used around the MAF sensor and in the intake pipe and the impact of temp changes on MAF readings and overall air intake temps.

- Total CFM that the system flows across all RPM ranges based on the design and filter used.

- Size and cleanliness of the air filter, along with airflow rate changes as the filter gets dirtier. Link: https://pdf.sciencedirectassets.com/...qa&type=client

- More relevant for non-boosted cars but many intakes (especially factory) have additional, side extensions/air reservoirs off the intake pipe behind the MAF tuned to the car's intake design. Link: https://itstillruns.com/air-intake-r...-12156112.html

- Sealing of the intake post-MAF, as unmetered air entering the engine affects how the car adjusts the air/fuel when it changes unexpectedly.

- Effects of blowby from PCV systems putting oil vapors/moisture etc into the air intake pipe (in systems where the PCV connects to the intake not the manifold/supercharger area).

- Any restrictions throughout the box but especially around the inlet, including the horn/bellmouth for the intake which has a giant plastic cover blocking a sizeable portion of it, along with the headlight electronics in front of it as well. Also, max possible airflow based on the MAF housing diameter and piping tapers, not just based on the filter.

- Design of the flange around the filter (velocity stack or bellmouth vs a flat mounting with a round hole in the middle). Link: https://en.wikipedia.org/wiki/Velocity_stack

- Curvature of the piping after the MAF affecting flow to and through the throttle body (sharp angles vs gradual tapers) and associated drag on airflow. Referenced by Vararam when designing their intakes. Link: http://www.vararam.com/VRDRX.html

- Impact of the design of the airbox on the engine startup procedures. Ford for example has specified in the past openly that they can detect air intake changes even if they go back to stock before hitting a dealership because it affects the way a cold engine warms up due to excessive airflow. Stock intakes are designed and tuned to work with the computer for appropriate warm up procedures to ensure durability of the engine. You can increase flow but the engine should be tuned to control rpm/timing of warmup too typically per Ford.

The stock airbox and filter setup is designed for laminar flow, noise control, snow ingestion mitigation, efficient cleaning of the air of course, appropriate warm up procedures for the engine, etc. Moral of the story is, the Rotofab may be able to flow more with the hood up indeed but there are other aspects of the stock intake that are not designed into the Rotofab. Not many people buy cold air intakes to manage all aspects of their performance, they just want noise and more airflow.


Regarding the power each mod set made:

The Rotofab with the hood up (red oiled filter, no the big gulp) made the most power overall, unsurprisingly do to the airflow capacity increase. About 15rwhp and 10wtq on the top end, tapering to minimal/nothing down low, SAE measured. This would be even more substantial with more boost or bigger blowers of course.

Rotofab and hood down made a few less horsepower and torque at the wheels SAE than stock. We raised the hood back up and re-pulled it and we were back to 10+hp gain over stock and ~10tq SAE. Drop the hood and it was down ~5p and ~!0tq from stock (heat soak likely the culprit for the worsening numbers). Direct example from Motor Trend: https://www.motortrend.com/how-to/gh...el-horsepower/

The snow ingestion cover removal didnt make any power over his stock dyno that we saw with a stock filter, but you could feel and tell a nice change in throttle response as the boost hits faster (not higher though, its mechanically limited).

I'll have to track down the dyno sheets and the videos if i can, and im sure people will be hating but essentially we had the same findings that EDFHOBBIES has posted data to support. My buddy is deployed at the moment so cant get him to send them right now.

My goal is not to crap on Rotofab, just simply to note what we saw when we messed with the ZL1 intakes. His car is a 19 A10 btw.

I did attach the stock graph from his car (lower dyno is his old mustang A10) so figure the values based on this. Very typical of 93 octane A10 stock pulls on a Dynojet.

We also did NOT see massive drops in power with repeated runs on the dyno but it did start to drop a little as it heat soaked, not 20-40whp or anything though. I'm sure this could technically happen in some really hot temps but we didnt see it in the 69 degree temp range with high humidity on that dyno day. We had plenty of fans going too to push air over the radiator, intake inlet and heat exchangers.

[Gunkk]

Originally Posted by FoundNemo

Drop the hood and it was down ~5p and ~!0tq from stock (heat soak likely the culprit for the worsening numbers).

This does not surprise me.

Originally Posted by LT4Greg

If the Roto-Fab CAI is not good then why do all the aftermarket companies that have parts for our cars use and recommend them in their builds?

Appeals to the extremes fallacies, aside... it is not a matter of "not good." The RF is better than the others in ways you may not perceive valuable as a consumer, but may as a vendor. It's vendor friendly: it's available, supported, and likely offers decent margins for the retailer. In other words, the standard RF intake is the best of a bunch of otherwise mediocre under hood "bling" mods that usually do more harm than good. It's also what customers are asking for. Gee, maybe ... just maybe ... all these aftermarket companies are actually in business to make money selling stuff to us. And if we want a little engine bay bling that doesn't otherwise make our cars run worse, maybe ... just maybe ... they'll shut up and take our money.


On the other hand, the Big Gulp is quite useful in supporting the airflow needs of high power builds, where there is little else worthy in the market.

[Camaro1973]

Originally Posted by FoundNemo

The rotofab will flow more with the hood up so when you dyno it, unrealistic gains are shown due to the airflow increase. EDFHOBBIES is spot on about this and its totally logical.

However, once you close the hood it effectively chokes off the filter on the top so its a false "gain" artificially inflated on the dyno. My buddy and I did back to back dyno testing on his car in Georgia with a Rotofab and the hood up, rotofab with hood down and the OEM airbox with the snow ingestion cover removed. All of the runs had the snow ingestion cover removed fyi.

Most people say when you get to speed it doesnt matter but it does, because total flow is not just the key aspect for intakes.

You also need to consider that power from air intakes is affected by all of the following:

- Laminar air flow across the MAF sensor (for MAF equipped cars) vs turbulence across the MAF sensors which can heavily impact power levels and driveability based on poor quality airflow readings (regardless of total cfm), which impacts how the car adjusts spark.

- Overall intake air temperature and the source of the air feed (turbulence, volume, temperature, etc)

- Rates of heat soak based on the material used around the MAF sensor and in the intake pipe and the impact of temp changes on MAF readings and overall air intake temps.

- Total CFM that the system flows across all RPM ranges based on the design and filter used.

- Size and cleanliness of the air filter, along with airflow rate changes as the filter gets dirtier.

- Sealing of the intake post-MAF, as unmetered air entering the engine affects how the car adjusts the air/fuel when it changes unexpectedly.

- Effects of blowby from PCV systems putting oil vapors/moisture etc into the air intake pipe (in systems where the PCV connects to the intake not the manifold/supercharger area).

- Any restrictions throughout the box but especially around the inlet, including the horn/bellmouth for the intake which has a giant plastic cover blocking a sizeable portion of it, along with the headlight electronics in front of it as well. Also, max possible airflow based on the MAF housing diameter and piping tapers, not just based on the filter.

- Design of the flange around the filter (velocity stack or bellmouth vs a flat mounting with a round hole in the middle).

- Curvature of the piping after the MAF affecting flow to and through the throttle body (sharp angles vs gradual tapers).

- Impact of the design of the airbox on the engine startup procedures. Ford for example has specified in the past openly that they can detect air intake changes even if they go back to stock before hitting a dealership because it affects the way a cold engine warms up due to excessive airflow. Stock intakes are designed and tuned to work with the computer for appropriate warm up procedures to ensure durability of the engine. You can increase flow but the engine should be tuned to control rpm/timing of warmup too typically per Ford.

The stock airbox and filter setup is designed for laminar flow, noise control, snow ingestion mitigation, efficient cleaning of the air of course, appropriate warm up procedures for the engine, etc. Moral of the story is, the Rotofab may be able to flow more with the hood up indeed but there are other aspects of the stock intake that are not designed into the Rotofab. Not many people buy cold air intakes to manage all aspects of their performance, they just want noise and more airflow.


Regarding the power each mod set made:

The Rotofab with the hood up (red oiled filter, no the big gulp) made the most power overall, unsurprisingly do to the airflow capacity increase. About 15rwhp and 10wtq on the top end, tapering to minimal/nothing down low, SAE measured. This would be even more substantial with more boost or bigger blowers of course.

Rotofab and hood down made a few less horsepower and torque at the wheels SAE than stock. We raised the hood back up and re-pulled it and we were back to 10+hp gain over stock and ~10tq SAE. Drop the hood and it was down ~5p and ~!0tq from stock (heat soak likely the culprit for the worsening numbers).

The snow ingestion cover removal didnt make any power over his stock dyno that we saw with a stock filter, but you could feel and tell a nice change in throttle response as the boost hits faster (not higher though, its mechanically limited).

I'll have to track down the dyno sheets and the videos if i can, and im sure people will be hating but essentially we had the same findings that EDFHOBBIES has posted data to support. My buddy is deployed at the moment so cant get him to send them right now.

My goal is not to crap on Rotofab, just simply to note what we saw when we messed with the ZL1 intakes. His car is a 19 A10 btw.

I did attach the stock graph from his car (lower dyno is his old mustang A10) so figure the values based on this. Very typical of 93 octane A10 stock pulls on a Dynojet.

We also did NOT see massive drops in power with repeated runs on the dyno but it did start to drop a little as it heat soaked, not 20-40whp or anything though. I'm sure this could technically happen in some really hot temps but we didnt see it in the 69 degree temp range with high humidity on that dyno day. We had plenty of fans going too to push air over the radiator, intake inlet and heat exchangers.

Horseshit. MAF/BOOST is identical with both the hood open/closed. Your theory about the top being choked off makes no sense. Airflow is exactly the same.

What is most likely going on is your closing the hood on a hot car with it sitting still on a dyno and the iats increased some.