OTR CAI tune with stock intake

[Banjo79]

Real man's CAI.

 

[07GTS]

there are videos showing stock airbox and vcm otr untuned gains and then tuned gains all back to back, n/a is more affected by intake restriction, any form of boosted is still affected but no where near as much, sometimes even a pod style can be better boosted as some OTR can deform the filter as it sucks more from one side on the LSA then the central OTR on earlier models

 

[Ginger Beer]

Airbox/filter setup is probably a bit more relevant on turbocharged engines. Unless oem airbox is very restrictive the engine cant suck in more air than it needs. I think the main advantage of otr cai is cooler air and more of it.

Ack, it depends on where your airbox gets its air, if you have an exposed pod in your engine bay it will suck hot air from there, but if you have a clean outside air path to a OEM airbox you get ambient temp air, my intake air temps with the OTR were higher than the OEM box when in traffic, it basically sucked air off the radiator, when mobile they were typical though

My hacked up airbox gets clean air from behind the front bar, not in front of the 85°c radiator, my only issue now is that the routing of my WTA intercooler in and out hoses are routed infront of my airbox, my temp IR temp gauge has the in hose around 30 to 40°c after a hit, with some heat proof sleeves covering them it would negate the increased air temp that the WTA coolant hoses "may" give



And as for intake volume of air, the throttle body size, and its feed pipe that is the main restriction, then it's how the heads flow in and out

At 100% volumetric efficacy, which it isn't, my old 5.7 uses around 30,000 ltrs of air a minute at 5k rpm, roughly...very roughly......

Currently my restriction is the exhaust, not my intake, as I have 1 5/8 tri-y pacies, I'm getting some ceramic coated, ininternally and exexternally coated, 1 7/8 4:1 long tube headers, which help with my exhaust flow, and lower engine temp, research has this lowering my boost but keeping my hp, with nil to minimal loss of torque down low

Apparently..........I'm no expert but I do have lots of spare time to play and overcomplicate things...

 

[RevNev]

Yes. That's how I found out about it. Came across sv black article and spotted it. What's your view on helmholtz chambers on this one. Do you think the only purpose is to keep the noise down ?

I don't think it's performance related Ron and solely about dampening induction noise. The Helmholtz addition isn't kind on the eye and would certainly look better without it. There used to be some factory like aftermarket smooth plastic MAF pipes, but I haven't seen any advertised for a few years.

 

[RevNev]

And as for intake volume of air, the throttle body size, and its feed pipe that is the main restriction, then it's how the heads flow in and out

That's right and many overlook this. The engine can only consume x amount of air depending on it's mechanical properties. Bigger air boxes, throttle bodies and manifolds do nothing when it's already consuming it's maximum of air. Ideally, the MAP reading should be at atmospheric pressure at full throttle and maximum horsepower. If the MAP pressure rises nearing maximum horsepower, the engine's intake restrictive somewhere between the air box and intake port. The LFX (SV6) engine gets a bit of pressure rise at 6000rpm I've noticed and could make a couple more with intake tidied up.

 

[moveage]

You can definitely overthink Cold Air Induction (CAI) on a GenIV. Firstly the purpose is not about (flow) restriction near stock where the factory unit flows 420 CFM.
Actual intake demand depends on quite a few things apart from RPM but bottom line is that with 300° advertised intake you are covered up to max torque (~4500) with stock intake. Taken to 5% redline margin at 100% VE max CFM is less than half that available with most aftermarket CAI -some OTR setups boast 1500+ CFM - totally ridiculous but the whole restriction thing is old school. What becomes important is velocity (air speed) in FPS when you introduce a massive cross section at an early length. Old schoolers just think oversized carb effect.
The centreline length from valve seat to plenum, its volume, through throttle opening area to second harmonic all affect tuning pressures more than oversized air-box and other pre throttle “flow restrictions”.
Ideal is about tuning predictability with reasonably cold air that is not turbulent, not air that changes drastically when idling in crawling traffic vs 125mph down a near freezing drag strip.
Given fixed cross section and runner length the importance of ECU being fed exact mass data for Electronic Throttle Control is far more important than affixing a branded bolt-on, when you don’t factor that by changing relevant parameters (tuning).
Logging MAF data near and beyond max torque is going to inform tuning, including size shape and location of mechanical devices pre TB to maximise velocity (torque) without sacrificing flow at high speed (HP).

 

[vr304]

^^ Pirate/monstar has been reborn, those who have been on here a while will know what I mean

 

[moveage]

^^ Pirate/monstar has been reborn, those who have been on here a while will know what I mean

Sorry, not with you?

 

[lmoengnr]

Sorry, not with you?

Hi Dirk!

 

[Banjo79]