1 2
GameboyRMH
GameboyRMH GRM+ Memberand MegaDork
5/18/22 9:44 a.m.

When I put together an intake for my AE92, I didn't have much flexibility in terms of routing but I took a lot of time to pick out the best components - I ended up going with an AEM Dryflow filter with the prefilter bag, and Spectre modular chromed ABS pipe. the filter offers good filtration and is washable (even with unofficial soaps wink) and the tubing is very lightweight and good at keeping engine bay heat out of the intake tract.

BillTaylor
BillTaylor New Reader
10/22/22 9:40 p.m.

In reply to mad_machine :

The original papers by the originators of the NACA ducts are online, mid 1940's. TL:DR, NACA ducts are Terrible for throttled intakes (Any varying intake volume), and only a few serious experimental aircraft turbine engine intakes ended all attempts. (Engine flame out on landing approach due to high angle of attack ruining intake flow is intensely demotivating.) Aviation NACA ducts are for constant flow to full time air flow uses, often cooling, but also cabin HVAC. They are overly sensitive to variable angles of approach air, which racing cars excel at riding on pneumatic tires which only develop side forces at notable slip angles. The turbulence following other racers is also poison to an efficient NACA duct flow.  NACA ducts perform best in high pressure areas. The image of the MGA is almost the worst possible placement. Optimum locations are found with water balances at speed, but almost always follow the same principles. Miata hoods are well researched, and the info is available. In contrast, the location shown (where it's normally most convenient for interior piping.) usually tests as enough of a low pressure area to be ideal for radiator air EXIT (See most LeMans prototypes, and newer Lotus), or just releasing hot engine compartment air. All current pro racing teams I'm aware of use Ram air, with an exterior scoop in most cases, if legal. All NASCAR teams I'm aware of use cowl induction, being the highest pressure area available that doesn't take damage in a 'rubbing is racing' league. Formula One is about ideal, an 'isolated from body flow' ram air duct with almost straight air path from opening to intake or turbo.

 

Note on flex tubing for performance sensitive airflow: Flow tests on accordioned tube show ID needs to be roughly 25% greater cross section than smooth tube to flow as well. This also strongly suggests transitions from smooth to accordioned, or accordioned to smooth tube are excellent opportunities to improve over almost all commonly available transitions. Expect resonance effects from each change in cross section Either way (Losses, unless well mated to engine RPMs), which is well understood in intake and exhaust runners, so minimized when it can't be used productively.

CapiDurazno
CapiDurazno New Reader
10/16/23 12:19 p.m.

Please advice

Ive been working on my Volvo P1800 , swap engine from a Volvo S40 , bigger turbo , now I found these article very interesting but would like some advice regarding how to imporve my Cold Air Intake for the turbo .

 

Please advice 

 

RobMason
RobMason New Reader
11/26/23 9:14 a.m.

In reply to CapiDurazno :

With the turbo - you have a hot air intake there taking air directly behind the hot radiator and just above the exhaust in a tight engine compartment without much air exit. Best and easiest thing to do would be to extend the intake straight forward, to the front of the radiator in the grille opening. Don't kniw how much room you have between radiator and side bulkhead though.

mr2peak
mr2peak GRM+ Memberand Dork
11/26/23 1:38 p.m.

In reply to CapiDurazno :

Hood scoop

mr2peak
mr2peak GRM+ Memberand Dork
11/29/23 10:01 p.m.

So 30* is 1hp, but how much does air temp affect knock? What is the relative reduction? 

stealthdeburgo
stealthdeburgo New Reader
12/23/24 3:20 p.m.

I just find it strange you would be placing super charger to a intake without tuned intakes (supercharger to head), you are missing out on quite a bit of ram air from the engine impulse induction, as well as placing a half decent inter cooler to lower compressed air temperature (big gains could be had here plus cooler running engine)

there are supercharger impulses from the roots type of blower, and those really need to be measured - and then fine turned for those particular impulses. there you may find a short stub is better than any long ones . harmonically I think those superchargers a several ratios higher then the general engine impulse tuning. hence using a shorter intake on the cool air intake side

 

crankwalk (Forum Supporter)
crankwalk (Forum Supporter) GRM+ Memberand UltraDork
12/23/24 3:32 p.m.
stealthdeburgo said:

I just find it strange you would be placing super charger to a intake without tuned intakes (supercharger to head), you are missing out on quite a bit of ram air from the engine impulse induction, as well as placing a half decent inter cooler to lower compressed air temperature (big gains could be had here plus cooler running engine)

there are supercharger impulses from the roots type of blower, and those really need to be measured - and then fine turned for those particular impulses. there you may find a short stub is better than any long ones . harmonically I think those superchargers a several ratios higher then the general engine impulse tuning. hence using a shorter intake on the cool air intake side

 

Is this AI? Lol

Any blower> No blower

1 2

You'll need to log in to post.

Our Preferred Partners
NwHf76do9Bh0VphRGi9BRec6f8cUIdBLRo6N4GNNV9HJePjmQ4QK6vE5lvtSOhzR