Cold engine performance

[Andy72]

Although its highly not recomended, i find my VTR (fitted with foam panel filter, 421 manifold and supersprint race system) goes like a bloody rocket when its cold. Once its warmed up, theres a definate drop in performance.

Im guessing this is telling me something, ie, the car could do with more fuel which is what its doing by itself for the cold running when the engine is cold.

Any thoughts and whats the best way to extract this extra performance the car seems capable of.

[pjm300]

is your manifold wrapped?

[Andy72]

nope. but i cant see it makes much difference as my induction is the standard induction kit, hence enclosed. I cant imagine im getting much heat soak from the manifold to make much difference?

(i have some wrap at home though, so may give it a try)

[JamesR]

its just that the air is colder, which means its denser which as we know = More BHP.

[DanT]

its just that the air is colder, which means its denser which as we know = More BHP.

LOL pretty sure he means the engine temperature not the air outside.

Could your car be running lean?

[Andy72]

no, what i mean is, when the engine is cold, ie from standing overnight, it has much more performance than when its warmed up to normal running tempreture. Im thinking this is hinting at my car not being set up right.

[MaRiO89]

I find my car is more responsive when cold, not that i boot it when cold as thats the last thing i would do but just pottering around the slightest touch of the throttle and it feels more responsive..

[Psycho18]

same here however once it has warmed up you can give it a good thrashing.

[evans1089]

is your manifold wrapped?

why would it matter if its wrapped?

[Alexvtrmk1]

Should'nt rag your car on a cold engine, it isnt good for it at all on the long term. Just wearing it down not giving it time to warm up. My performance is sh*t when i first start up, my performance is mint on a cold night and engine warmed up, and my perfomance is good on a cool day and probably not as good on a hot day :)

[KamRacing]

you really need to get the fueling checked then when the car is warmed up.

Adjusting the fueling will require an ECU remap or aftermarket ECU

[Steve]

Should'nt rag your car on a cold engine, it isnt good for it at all on the long term. Just wearing it down not giving it time to warm up. My performance is sh*t when i first start up, my performance is mint on a cold night and engine warmed up, and my perfomance is good on a cool day and probably not as good on a hot day :)

he never said he ragged it from cold ;)

Andy i used to get this is my VTR to, i just wrote it off in the end however, got sick of it lol :afro:

[Alexvtrmk1]

he never said he ragged it from cold ;)

Andy i used to get this is my VTR to, i just wrote it off in the end however, got sick of it lol :afro:

So he didnt lol...my bad ;)

[kieranc07]

maby its the auto choke giving it bit more fuel so it goes a treat ?:)

kieran.

[shaunyboy]

Most probaby a mixture of air temp in the cylinder and the fueling my 50 2 stroke used to do it, when warm it bogged down a bit.

[Andy72]

Most probaby a mixture of air temp in the cylinder and the fueling my 50 2 stroke used to do it, when warm it bogged down a bit.

thats exactly what i thought, question is, is this telling me i need a remap etc to get the same performance when the car is warmed up, as the car is obviously capable of better performance

[gixxa]

could be as simple as the the air getting warmed up in the inlet manifold as it go's into the ports

[Sparco_Tom]

just sounds like your engine bay is heating up, warming the air as it enters the cylinders. Therefore losing abit of power once you get going

[shaunyboy]

Could do with an enclosed induction like the BMC's if you havent already got one, and if you have a 4-1 manifold heat wrap it if its not. Then see about a remap, could try taking the plugs out and see how its running mate.

[stingray1987]

most cars are the same. if i rember right you can put a resistor sumwhere to fool the ecu to thinking the engine is cold all the time to get the same responce. but herd its no good for your engine.

its the same with all cars.
my punto and polo did it aswell as my saxo there must be a reason for it but what i dnt know.
but yeah i wouldnt recomend thrashing it when cold.
but as also stated that wasnt said so ill stay out of this one lol

[shaunyboy]

most cars are the same. if i rember right you can put a resistor sumwhere to fool the ecu to thinking the engine is cold all the time to get the same responce. but herd its no good for your engine.

its the same with all cars.
my punto and polo did it aswell as my saxo there must be a reason for it but what i dnt know.
but yeah i wouldnt recomend thrashing it when cold.
but as also stated that wasnt said so ill stay out of this one lol

Thats the shit way of doing it, it will still bog down when warm as its just running rich then, with mapping you can fine tune the fueling hence get the most out of it, a petrol re-map can add arround 7 - 15bhp roughly and will lighten up the throttle response.