15$ DIY cold induction mod

I developed this DIY performance enhancing mod here. The basic concept could done to any car with similar layout/technology used.

www.austarletclub.com...

I think you may have hear this adage: "you gain 1 hp per 10 F degree drop in intake temperature" I did not take temperature readings but before the mod, the intake manifold is too hot to touch. After the mod, the manifold is tad cooler even than my body temperature!

One thing I did however is time my 0-100 kph, between mods, I gained 15% horsepower or 9.9 hp from my previous 65 hp output. Fuel economy improved by 11%

The mods has survived 7000 kms of severe driving conditions already without any sign of deterioration. The engine is regularly red-lined when doing some rally driving on weekends. The dramatic reduction of manifold temps did not cause lean running or any negative consequences to the engine (spark plugs showed normal combustion) Enjoy!

reply to post by ahnggk

One thing I did however is time my 0-100 kph, between mods, I gained 15% horsepower or 9.9 hp from my previous 65 hp output. Fuel economy improved by 11%

How did you determine this with just a 0-100km run?

No dynos?

That's pretty good if you're getting that much of a performance boost out of it. Interesting to see how it holds out in the long run though.

reply to post by ahnggk


hmmm intake too hot to touch leads me to believe you have throttle body injection and hot coolant in a jacketed intake manifold to help vaporize fuel..... ideally this is how they are designed to operate. this is confirmed by the black hoses running off your intake manifold to your head. modifying to cut off the flow of coolant to the intake manifold will cause you problems in cold weather. also reducing coolant flow to the head.

Originally posted by Chadwickus
How did you determine this with just a 0-100km run?

No dynos?

Time 0-100 and with this calculator:

www.060calculator.com...

Did 13 seconds flat previously and got it down to 11.73. Before any of those mods, acceleration was 17 seconds to 100 kph. Most of the improvement came from tweaking the auto transmission cable. Not mentioned previously is I used a street racing oil and 1 step colder spark plugs for the test so I could red line the engine safely. Got no money to spare for dyno so I think that'll do!

The test car(my daily), a '96 Toyota Starlet could do 40+ mpg(even without any mods) Is not supposed to be a high performance car. But it's quite fun, reliably boosting this fuel saver with only very little spent.

Originally posted by TrueInstinct
That's pretty good if you're getting that much of a performance boost out of it. Interesting to see how it holds out in the long run though.

About 8000 kilometers(severe conditions) traveled now with those mods and checked engine and mods. Idle: within specs, vacuum: ok, coolant and oil: normal and no mixing, spark plugs: shows combustion is perfect...

...The mods themselves did not change a bit.

Originally posted by Majestyka
hmmm intake too hot to touch leads me to believe you have throttle body injection and hot coolant in a jacketed intake manifold to help vaporize fuel..... ideally this is how they are designed to operate. this is confirmed by the black hoses running off your intake manifold to your head. modifying to cut off the flow of coolant to the intake manifold will cause you problems in cold weather. also reducing coolant flow to the head.

Thanks for pointing this out The engine I have is a Toyota 4efe. The fuel injectors are right in the cylinder head so there's little chance of fuel getting to the manifold if any. The throttle body does not contain any fuel lines, only small vacuum hoses. No vaporization issues so far - which will reduce fuel economy and cause the cat to overheat. In fact, as I've stated earlier, fuel economy improved with this mod.

In the case you've pointed out, then don't do the coolant bypass mod on a carbureted engine as manifold and T/B heat does help in vaporization and prevent carb icing. I'll add your concern in the linked page as a warning(I can't edit my OP anymore)

I did some research on throttle body coolant flow beforehand on an EFI engine. What it does is to prevent freezing in very cold weather and cause the throttle to get stuck. In actual conditions, the intake manifold and throttle body is still getting radiant heat from the engine(after running the car at high throttle at working temps and quickly getting a reading at night). My estimate is that it would take an ambient temp of -10'Celsius to cause freezing issues down the throttle body.

Just to be safe, if temperatures in your region is expected to drop below -5 Celsius, then skip the throttle body coolant bypass part! And don't bypass coolant on a carbureted engine (only applicable on EFI engines)

Where I come from its all :FACEPALM: but some really dont know about basic automotive modifications...

A K&N filter will give you better fuel economy than a stock filter, no IFS, no BUTS.

PS: "Chadwickus", I really hope your not the son of my old mechanics teacher at Jonno, Mr Chadwick. Old green Dodge pickup???

acceleration was 17 seconds to 100 kph...

and you think thats impressive? a Landrover can do that stock. www.zeroto60times.com...

to the OP: Starlet Club??? seriously? do you even know what a car is??.

on my Z (300zx z31--dont laugh!) i got about 50kms more per tank on a K&N filter than stock, more if I juiced it with 98RON, sure mods can increase your at-the-wheels HP and reduce your fuel economy, but what you linked to was a forum filled with people who have NO idea about cars--OTHERWISE THEY WOULD HAVE NOT PURCHASED A STARLET!!!.

Front wheel drive == you dont know how to

Unless you're doing your performance tests down at the drag strip wi proper timing gear then the performance tests arent that accurate,it's incredibly hard to replicate each test run to a meaningful degree without properly set up equipment.

The real proof is in real world driveability rather than timed sprints.

Would love to know how you calculated your hp figures.A 10 bhp increase from a 65 bhp motor is incredible and somewhat hard to believe without some validation,or at without knowing your method.

Would agree with your basic thinking.A lot of multipoint fuel injection engines run without any real water cooling of the plenum/manifold and can get real hot to the touch from simply heat transtfer from the engine.A good heat insulated sandwich btwn manifold and head CAN keep your manifold that much cooler.

Of course this is free power as the cooler air is denser with more oxygen though the volume of air is the same so your it shouldnt lean the air/fuel ratio much.

Again isolating your airbox from engine heat will help too.Fitting a feed tube from an outside air source direct to the body of the air cleaner will feed in cool air and promote a ram air effect aswell.

The ideal place to feed air from would prob be the middle of the front bumper to benefit from the highest air pressure but that isnt always practical.lol.

For cars running EFi it's a good idea to find out what way your engine senses load as increasing the airflow can effect it negatively.

If you motor uses a mass airflow sensor then it's much less of an issue but with a manifold absolute pressure system it's unable to adjust sense the increase in airflow and adjust in response making it much more likely your engine will run lean.

If you want to further lower the ambient temp in the eng bay exhaust wraps worth considering as it cuts down on the heat the exhaust radiates with the added benefit that hotter exhaust gases that are less dense and more easily flowed down the exhaust system further aiding cylinder scavengeing !!!

The comment about fittng a K'N will make it flow better no ifs and buts is a little simplistic.
If you're talking panel filter than it will flow a bit better but the issue is determining were in the intake system the main restriction is,often through the flow meter or the outlet in the airbox's lid both after the element so changing filter would have a minimal effect.

induction kits are problematic for road cars that arent mödified.they draw in hot air,are prone to pressure wave reverves as the throttle opens and shuts.The standard box dampens the waves.

Again in a motor that uses a MAP sensor to calculate engine load it'll run lean,a MAF sensor has scope for some fueling adjustment in response to the changed airflow.

If you want to cool the engine bay consider lowering underbonnet pressure and helping the air already there to exit quick and easy !!!

Unless you're doing your performance tests down at the drag strip wi proper timing gear then the performance tests arent that accurate,it's incredibly hard to replicate each test run to a meaningful degree without properly set up equipment.

The real proof is in real world driveability rather than timed sprints.

Would love to know how you calculated your hp figures.A 10 bhp increase from a 65 bhp motor is incredible and somewhat hard to believe without some validation,or at without knowing your method.

Would agree with your basic thinking.A lot of multipoint fuel injection engines run without any real water cooling of the plenum/manifold and can get real hot to the touch from simply heat transtfer from the engine.A good heat insulated sandwich btwn manifold and head CAN keep your manifold that much cooler.

Of course this is free power as the cooler air is denser with more oxygen though the volume of air is the same so your it shouldnt lean the air/fuel ratio much.

Again isolating your airbox from engine heat will help too.Fitting a feed tube from an outside air source direct to the body of the air cleaner will feed in cool air and promote a ram air effect aswell.

The ideal place to feed air from would prob be the middle of the front bumper to benefit from the highest air pressure but that isnt always practical.lol.

For cars running EFi it's a good idea to find out what way your engine senses load as increasing the airflow can effect it negatively.

If you motor uses a mass airflow sensor then it's much less of an issue but with a manifold absolute pressure system it's unable to adjust sense the increase in airflow and adjust in response making it much more likely your engine will run lean.

If you want to further lower the ambient temp in the eng bay exhaust wraps worth considering as it cuts down on the heat the exhaust radiates with the added benefit that hotter exhaust gases that are less dense and more easily flowed down the exhaust system further aiding cylinder scavengeing !!!

The comment about fittng a K'N will make it flow better no ifs and buts is a little simplistic.
If you're talking panel filter than it will flow a bit better but the issue is determining were in the intake system the main restriction is,often through the flow meter or the outlet in the airbox's lid both after the element so changing filter would have a minimal effect.

induction kits are problematic for road cars that arent mödified.they draw in hot air,are prone to pressure wave reverves as the throttle opens and shuts.The standard box dampens the waves.

Again in a motor that uses a MAP sensor to calculate engine load it'll run lean,a MAF sensor has scope for some fueling adjustment in response to the changed airflow.

If you want to cool the engine bay consider lowering underbonnet pressure and helping the air already there to exit quick and easy !!!

Unless you're doing your performance tests down at the drag strip wi proper timing gear then the performance tests arent that accurate,it's incredibly hard to replicate each test run to a meaningful degree without properly set up equipment.

The real proof is in real world driveability rather than timed sprints.

Would love to know how you calculated your hp figures.A 10 bhp increase from a 65 bhp motor is incredible and somewhat hard to believe without some validation,or at without knowing your method.

Would agree with your basic thinking.A lot of multipoint fuel injection engines run without any real water cooling of the plenum/manifold and can get real hot to the touch from simply heat transtfer from the engine.A good heat insulated sandwich btwn manifold and head CAN keep your manifold that much cooler.

Of course this is free power as the cooler air is denser with more oxygen though the volume of air is the same so your it shouldnt lean the air/fuel ratio much.

Again isolating your airbox from engine heat will help too.Fitting a feed tube from an outside air source direct to the body of the air cleaner will feed in cool air and promote a ram air effect aswell.

The ideal place to feed air from would prob be the middle of the front bumper to benefit from the highest air pressure but that isnt always practical.lol.

For cars running EFi it's a good idea to find out what way your engine senses load as increasing the airflow can effect it negatively.

If you motor uses a mass airflow sensor then it's much less of an issue but with a manifold absolute pressure system it's unable to adjust sense the increase in airflow and adjust in response making it much more likely your engine will run lean.

If you want to further lower the ambient temp in the eng bay exhaust wraps worth considering as it cuts down on the heat the exhaust radiates with the added benefit that hotter exhaust gases that are less dense and more easily flowed down the exhaust system further aiding cylinder scavengeing !!!

The comment about fittng a K'N will make it flow better no ifs and buts is a little simplistic.
If you're talking panel filter than it will flow a bit better but the issue is determining were in the intake system the main restriction is,often through the flow meter or the outlet in the airbox's lid both after the element so changing filter would have a minimal effect.

induction kits are problematic for road cars that arent mödified.they draw in hot air,are prone to pressure wave reverves as the throttle opens and shuts.The standard box dampens the waves.

Again in a motor that uses a MAP sensor to calculate engine load it'll run lean,a MAF sensor has scope for some fueling adjustment in response to the changed airflow.

If you want to cool the engine bay consider lowering underbonnet pressure and helping the air already there to exit quick and easy !!!

Unless you're doing your performance tests down at the drag strip wi proper timing gear then the performance tests arent that accurate,it's incredibly hard to replicate each test run to a meaningful degree without properly set up equipment.

The real proof is in real world driveability rather than timed sprints.

Would love to know how you calculated your hp figures.A 10 bhp increase from a 65 bhp motor is incredible and somewhat hard to believe without some validation,or at without knowing your method.

Would agree with your basic thinking.A lot of multipoint fuel injection engines run without any real water cooling of the plenum/manifold and can get real hot to the touch from simply heat transtfer from the engine.A good heat insulated sandwich btwn manifold and head CAN keep your manifold that much cooler.

Of course this is free power as the cooler air is denser with more oxygen though the volume of air is the same so your it shouldnt lean the air/fuel ratio much.

Again isolating your airbox from engine heat will help too.Fitting a feed tube from an outside air source direct to the body of the air cleaner will feed in cool air and promote a ram air effect aswell.

The ideal place to feed air from would prob be the middle of the front bumper to benefit from the highest air pressure but that isnt always practical.lol.

For cars running EFi it's a good idea to find out what way your engine senses load as increasing the airflow can effect it negatively.

If you motor uses a mass airflow sensor then it's much less of an issue but with a manifold absolute pressure system it's unable to adjust sense the increase in airflow and adjust in response making it much more likely your engine will run lean.

If you want to further lower the ambient temp in the eng bay exhaust wraps worth considering as it cuts down on the heat the exhaust radiates with the added benefit that hotter exhaust gases that are less dense and more easily flowed down the exhaust system further aiding cylinder scavengeing !!!

The comment about fittng a K'N will make it flow better no ifs and buts is a little simplistic.
If you're talking panel filter than it will flow a bit better but the issue is determining were in the intake system the main restriction is,often through the flow meter or the outlet in the airbox's lid both after the element so changing filter would have a minimal effect.

induction kits are problematic for road cars that arent mödified.they draw in hot air,are prone to pressure wave reverves as the throttle opens and shuts.The standard box dampens the waves.

Again in a motor that uses a MAP sensor to calculate engine load it'll run lean,a MAF sensor has scope for some fueling adjustment in response to the changed airflow.

If you want to cool the engine bay consider lowering underbonnet pressure and helping the air already there to exit quick and easy !!!