Blox Velocity Stack and Filter ~DYNO COMPARISON~
Hey guys. On Sept. 12th I went to a dyno day so I could test a new intake setup I got. I got the Blox velocity stack and Blox filter. I wanted to see what, if any increase there would be in power versus my current setup. Currently it’s just a 3” intake with a basic filter on it. Keep in mind that this is all unturned. I’m running a stock obd1 gsr ecu in my CRX.
The rest of the setup is as follows:
Stock obd2 GSR motor
RMF replica header
2.25” exhaust with no cat, exiting a stock replacement muffler to keep it quiet for daily driving.
Stock tb and intake manifold. I’ve never been able to confirm if the secondary butterflies work properly. Every test I tried, showed me nothing and I cannot hear them open up.
1st run-Green-Original intake setup
2nd run-Red-only velocity stack
3rd run-Blue-velocity stack with filter
Overall, it did much better without the filter on the velocity stack. It yielded better hp and torque through the power band until about 6000 RPM, where all the set ups kind of equalize and it comes back out on top at peak rpm.
The stack with the filter on it yielded more hp and tq between 6K and 7K RPM. Until you get to 5500 RPM, the stack and filter perform about the same as the old set up.

The rest of the setup is as follows:
Stock obd2 GSR motor
RMF replica header
2.25” exhaust with no cat, exiting a stock replacement muffler to keep it quiet for daily driving.
Stock tb and intake manifold. I’ve never been able to confirm if the secondary butterflies work properly. Every test I tried, showed me nothing and I cannot hear them open up.
1st run-Green-Original intake setup
2nd run-Red-only velocity stack
3rd run-Blue-velocity stack with filter
Overall, it did much better without the filter on the velocity stack. It yielded better hp and torque through the power band until about 6000 RPM, where all the set ups kind of equalize and it comes back out on top at peak rpm.
The stack with the filter on it yielded more hp and tq between 6K and 7K RPM. Until you get to 5500 RPM, the stack and filter perform about the same as the old set up.

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The secondaries are NOT opening, unless you wired in a relay to have them open. The OBD1 and OBD2 ECU operated the secondaries differently. Between 4600-5800 you're running rich. Normally the secondaries have change the air flow so the ECU is putting more fuel in.
Get this sucker tuned and clean up the A/F.
What kind of gains did you get from 6k up? Looks like about 5hp or so.
Get this sucker tuned and clean up the A/F.
What kind of gains did you get from 6k up? Looks like about 5hp or so.
I was thinking the same thing. I never felt that pick up at 6K until I installed the RMF header though, so I just thought it was the header doing some good for my top end.
Yep! The velocity stacks are identical, but the filters may be different. BPI's filter costs about 2X as much.
Yep! The velocity stacks are identical, but the filters may be different. BPI's filter costs about 2X as much.
The secondaries are NOT opening, unless you wired in a relay to have them open. The OBD1 and OBD2 ECU operated the secondaries differently. Between 4600-5800 you're running rich. Normally the secondaries have change the air flow so the ECU is putting more fuel in.
Get this sucker tuned and clean up the A/F.
What kind of gains did you get from 6k up? Looks like about 5hp or so.
Get this sucker tuned and clean up the A/F.
What kind of gains did you get from 6k up? Looks like about 5hp or so.
You need a relay. This is a fact, period. Why, OBD1 ECU is a negative ground and the OBD2 ECU is a positive ground for the IAB circuit. I might have this backwards but regardless you will need a relay.
If you have your car tuned correctly it should almost sound like to have two VTEC points. Actual VTEC and when the IAB open up. This actually sounds really cool.
I don't know how to wire the relay, my tuner did it. I could try to take a picture.
Good comparision.
On my itr, i put a 3'' SRI and vstack w/o filter.
Had to add over 15% fuel all over the map just to get the AFR back to normal.. picked up some good power.. specially up top..
Love bpi vstacks.
On my itr, i put a 3'' SRI and vstack w/o filter.
Had to add over 15% fuel all over the map just to get the AFR back to normal.. picked up some good power.. specially up top..
Love bpi vstacks.
Chris if you can wait till I get my car back up to SC I'll sell you the AEBS manifold and port matched TB out of the GSR for less than the S2P will run you. Or get in touch with Alex from Humble Performance on here he is a sponsor. He took great care of me when I got my AEBS from him.
Oh and your a gay fish.
Oh and your a gay fish.
I have an OBD2 engine and a OBD1 ECU running my 1999 GSR right now. I am running a Hondata S300.
You need a relay. This is a fact, period. Why, OBD1 ECU is a negative ground and the OBD2 ECU is a positive ground for the IAB circuit. I might have this backwards but regardless you will need a relay.
If you have your car tuned correctly it should almost sound like to have two VTEC points. Actual VTEC and when the IAB open up. This actually sounds really cool.
I don't know how to wire the relay, my tuner did it. I could try to take a picture.
You need a relay. This is a fact, period. Why, OBD1 ECU is a negative ground and the OBD2 ECU is a positive ground for the IAB circuit. I might have this backwards but regardless you will need a relay.
If you have your car tuned correctly it should almost sound like to have two VTEC points. Actual VTEC and when the IAB open up. This actually sounds really cool.
I don't know how to wire the relay, my tuner did it. I could try to take a picture.
You may want to ask this question in the Engine Management and Tuning forum. Someone might have details more easily available.
Interesting, I also tested this out of curiosity. My results had a slightly more drastic difference:

Red: Shop "magic arm" intake
Blue: 3" Short Ram with Blox Velocity Stack
Yellow: 3" Short Ram with Blox Velocity Stack and Blox Filter
Don't mean to threadjack, just want to contribute

Red: Shop "magic arm" intake
Blue: 3" Short Ram with Blox Velocity Stack
Yellow: 3" Short Ram with Blox Velocity Stack and Blox Filter
Don't mean to threadjack, just want to contribute
Interesting! Was it actually an intake or just some 4 foot long piece of pipe? At that length, I dont see how it could fit under the hood!
LOL
LOL
It's a pretty common setup, lots of dyno operators have one lying around. It isn't really designed to fit in the engine bay, it just sort of sticks out with the hood up. Although, some drag racers remove the passenger side headlight, and have one stick out there with a velocity stack on the end.
basically, it looks like a short ram, but instead of the long section being like 12", its like three feet or so.
here is an example:


(not mine)
here is my short ram for comparison:
basically, it looks like a short ram, but instead of the long section being like 12", its like three feet or so.
here is an example:


(not mine)
here is my short ram for comparison:
So in conclusion, besides WrongWD's "Magic Arm" with velocity stack no one else has made any significant gains in power with a velocity stack with/without filter.



