Creating a new Airbox for the Firebird.

[TransAmDan]

Took the MAF

Added a clamp to protest the delicate wires.

Dremel cutting it up.

Starting to make it fit the oval.

Wired added to connect tot he black box.

Really happy with how it looks

Rubber seal added.

Sounds like a vacumm cleaner.

I'm very happy with it all though. Letting it run up to temprature while checking for leaks of fuel or water.

Took it out for a test drive, not putting it under any load apart from light throttle as I knew the fueling is way out. Data logged that drive. Looks like I need to remove 4% of fuel on light load, but add near on 8% on slightly more load. The car is learning. Its all within learning limits.

Certainly more tunning needed. The MAF sensor isn't connected, but I did test it on the desk and it producing variying waveforms depending on airflow.

 

[TransAmDan]

The video on Youtube is certainly getting some views. People commenting on it. Great to see. I'll get a longer "how its made" type video going on it.

 

[TransAmDan]

The air filter noise on ideal attracted a few people interst on youTube, and they wondered what does it sounds like when engin revs get higher. Well couldn't do this at home, so went down the country lanes away from people.
Created a short video. Mind you took around 6 hours to edit and upload, hopefully I get faster at this. lol.

I was surpriced the air entering the filters got quieter with higher revs.

 

[saleen 192]

Just putting a claim in for blown speakers lol.

 

[TransAmDan]

Tuning going well. Idling is pretty much dialed in. Giving it some beans feels good.

Almost 500ft/lbs tq, should get over 500hp at 6000rpm The torque is calcualted by the car from grtamg or air in the cylinders along with a few other factors, its ment to be +/- 15 ft/lbs of torque which is great for me tuning.The HP is purely a calc from TQ.

I think I'm going to get around 510tq/540hp with further tuning.

This leads me to another issue, my fuel pump is an upgraded flow one and rattedat 255lph, however from this table, it getting near its limit.

I'm tempted to but the AEM350lph. Available in the UK for £111 https://www.demon-tweeks.com/uk/aem-electronics-320lph-high-flow-in-tank-fuel-pump-aem50-1000/

My fuse for the pump is 15A. I may need to run in a larger wire to the pump to avaoid volt drops.

Would also be nice to get a fuel pressure guage on the dash to see if it is dropping. I may do that before the pump change.

 

[saleen 192]

Turbosmart 0-100 PSI Liquid Filled Fuel Pressure Gauge

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www.demon-tweeks.com

I run fuel pressure gauge on fuel rail in engine about 40 psi. In dash might be good idea for tuning with the lap top next to you. Dosnt your computer monitor fuel pressure through your obd port? My two scan tools do.

 

[TransAmDan]

Looking to see if the Ram-Air effect can be improved. Needing to find out how large the Nostrils air to work out the effective area.

Estimated Airflow Area

• Each nostril opening is roughly 3.5" wide by 2.5" tall at its most open point.
• However, the plastic grille and internal ducting reduce the effective area by about 30–40%.

We have around 12inch square aera.

Probably worth me printing a different grille to maximize air flow. Also could smooth off the air under the hood, it goes through a letter box type opening as part of the fibreglass of the hood. This can be easily trimmed.

So how much gains is possible?

What We Know
- Effective area: Let’s assume 12 in² (0.0833 ft²) for both nostrils combined after grille losses.
- Air velocity: Depends on vehicle speed. We'll calculate for:
- 70 mph (31.3 m/s)
- 100 mph (44.7 m/s)
- 170 mph (76.0 m/s)

What We Know

• Effective area: Let’s assume 12 in² (0.0833 ft²) for both nostrils combined after grille losses.
• Air velocity: Depends on vehicle speed. We'll calculate for:
• 70 mph (31.3 m/s)
• 100 mph (44.7 m/s)
• 170 mph (76.0 m/s)

Dynamic Pressure Estimates at the WS6 scoop:

Speed (MPH)​	Velocity (m/s)​	Dynamic Pressure (Pa)​	Dynamic Pressure (PSI)​	Power Increase
70​	31.3​	599​	0.087​	+0.5%
100​	44.7​	1223​	0.178​	+1.2%
170​	76.0​	3537​	0.513​	+3.5%

So it would seem at 170mph, I could gain 17 extra HP and 16 lb-ft of torque.
Not that I will be going there. Still some gain at 70mph or around 2.5hp. Its free power. Unfortunately not measurable on the dyno.

 

[TransAmDan]

How much can the new filter set up flow, have I made the right desision going dual cones?

Estimated Stock Filter Flow:

• Stock paper filter: ~450–500 CFM at 1.5" H₂O pressure drop
• K&N drop-in replacement: ~600–650 CFM under the same conditions

That means my current setup with dual RE-0950 filters (each rated around 450–500 CFM) is flowing nearly double what the stock filter could handle—900–1000+ CFM total, with lower restriction and better high-RPM breathing.

Why It Matters:

• At 7000 RPM, your 383ci LS1 demands ~770 CFM. The stock filter would be borderline restrictive, especially with the BTR Stage 4 cam and long tubes.
• The sealed ram-air box and dual 3.5" filters gives headroom, which helps maintain VE and throttle response at high speed.

So certainly needed to do something with the air box, srock air box just couldn't supply the air for all my mods. The dual cone filters give me more than enough flow.

Was great to go through these numbers.