Car feels like its slower on a hot..

[Addicted2Kouki]

Well.. a couple months ago I went KA-t.
my current setup is...

-GT28r [S15 Turbo]
-S15 Fuel pump
-z32 fuel filter
-370cc injectors
-N60 mafs
-SR SMIC w/ stock s13 piping.
-Chipped ECU
---7psi off the wastegate

Anyways,
I noticed on hot days, my car feels a lot slower.
Most noticeable when city driving [part throttle acceleration, stop and go.]
Still boosts fine. When it hits boost, its still fast but not AS fast.

I'm usually out during the night, so I only noticed it recently.

Funny thing is,
I can drive the car and feel slow during the day,
yet when it cools down...
It feels normal and a lot faster.

Gas mileage also isn't as good on a hot day,
but that was apparent even when I wasn't turbo.

Anybody have any clue as to what it is?

[JVD]

How much of a difference is it?

Turbo cars are gonna like the cold. Cooler = denser air.

Also... 7psi... ugh. Doesn't it always feel slow? LOL. Jk.

[njd07]

lol 7psi...im running 12 on my t25 and that feels slow. so use to having 16psi on a t28.

[projekt_s13]

I find it harder to run on a very hot day, but on a cool day i can run really fast.

[tt99ol]

it really is just an air density thing
hotter air is less dense
add a psi or 2 during the day and it should feel similar then at night
or intercooler water sprayers

[renegade_ewok]

If your doing city driving you'll heatsoak a lot of stuff fast. I've had a vacuum line melt while sitting in traffic in philly and my intake temps to rise up to 160 degrees over the summer. This is on an SR, but turbo KA is essentially will make the same if not more heat.

[murda-c]

I was driving my nitro RC cars in the winter, bitches were fast as hell. summertime comes along, they get mad slow.

How are your water/oil temps? Do you have the A/C on?

A/C=crazy heat.

[DirtyS14]

My car usually feels a lot slower on hot days. Like the others said its an air density thing.

The thinner air is more difficult for the turbocharger to pull in and the decreased density affects combustion in a bad way.

[s14jesse]

well hot days would be the enemy of a turbo car i feel my car a little slower when its hot im guessing thats normal and u have a smic so ur not getting alot of air period as u would with a fmic

[Addicted2Kouki]

Originally Posted by JVD

How much of a difference is it?

Turbo cars are gonna like the cold. Cooler = denser air.

Also... 7psi... ugh. Doesn't it always feel slow? LOL. Jk.

difference is drastic enough to feel it.

Originally Posted by projekt_s13

I find it harder to run on a very hot day, but on a cool day i can run really fast.

thats what im talkin about!

Originally Posted by tt99ol

it really is just an air density thing
hotter air is less dense
add a psi or 2 during the day and it should feel similar then at night
or intercooler water sprayers

i was thinking that..

Originally Posted by renegade_ewok

If your doing city driving you'll heatsoak a lot of stuff fast. I've had a vacuum line melt while sitting in traffic in philly and my intake temps to rise up to 160 degrees over the summer. This is on an SR, but turbo KA is essentially will make the same if not more heat.

yeah just bought a front mount. i think it should help... a lil.

Originally Posted by murda-c

I was driving my nitro RC cars in the winter, bitches were fast as hell. summertime comes along, they get mad slow.

How are your water/oil temps? Do you have the A/C on?

A/C=crazy heat.

hrmm. interesting.
Water and Oil temps... no clue.
General idea from the crappy stock gauge tells me
that when I'm cruising.. temps go a lil lower,
sitting at a light it gets pretty warm.
I know I know...
I'm supposed to have bought gauges for that blah blah blah.

No money at the moment. Buy me a gauge and I'll let you know.


On another note... I'm running an aluminum radiator with altima fans.

Originally Posted by DirtyS14

My car usually feels a lot slower on hot days. Like the others said its an air density thing.

The thinner air is more difficult for the turbocharger to pull in and the decreased density affects combustion in a bad way.

Damn air density.. any way to improve?

[murda-c]

The only thing you can really do is have a big front mount intercooler with lots of airflow, but thats not gonna do much around town, it'll still heat soak in traffic, just take longer.

Really just make sure your cooling system works well, and know you're gonna lose power on hot days or at high altitudes.

[Addicted2Kouki]

Originally Posted by murda-c

The only thing you can really do is have a big front mount intercooler with lots of airflow, but thats not gonna do much around town, it'll still heat soak in traffic, just take longer.

Really just make sure your cooling system works well, and know you're gonna lose power on hot days or at high altitudes.

you think a fan on the intercooler would help?

[murda-c]

An intercooler fan would help, I've seen it done on MR2s

But really a front mount is where it's at.

You can paint it with black radiator paint if you wanna keep it sleeper.

[Addicted2Kouki]

Originally Posted by murda-c

An intercooler fan would help, I've seen it done on MR2s

But really a front mount is where it's at.

You can paint it with black radiator paint if you wanna keep it sleeper.

Well, I do have a front mount.
Just didnt throw it on yet.

Would the fan help it on the front mount for city driving?

[slow40sx]

Originally Posted by Addicted2Kouki

Well, I do have a front mount.
Just didnt throw it on yet.

Would the fan help it on the front mount for city driving?

please don't put a fan on your front mount

[ESmorz]

That's where it's at.

[illvialuver]

i noticed the same thing with my old ka-t set up. i had a t3 t4 setup and was runin a walboro 255 and the usual t3 t4 stuff. it always ran slower and got worse gas milage on hotter days.
just start heat wrapping as much shit as possible. it cant hurt seeing as how heat makes you lose horse power.
plus run better oil. highly recomend the royal purp.

[projekt_s13]

ahahaha intercooler intake. My friend did that on his DA integra, made the car lagg and run like shit.

[Addicted2Kouki]

Originally Posted by slow40sx

please don't put a fan on your front mount

wtf makes you so knowledgeable to tell me no?
it was stated up there that other cars have had fans on their intercoolers.
I dont see how it could negatively impact anything.


if you are going to state your opinion, atleast say why.

[Addicted2Kouki]

Originally Posted by projekt_s13

ahahaha intercooler intake. My friend did that on his DA integra, made the car lagg and run like shit.

I never understood those hahaa.

[blu808]

Yea just air density. But it has more to do with affecting the timing because of the density than just saying the charge is less dense. This is less noticeable on speed density cars.

But yes. My 300zx used to spin em up through 4th gear on a cold night. Even if the tires were hot. Then on a 100 deg day it would loose a good 40 whp.

Even on my daily driver (05 gto). I loose a good 30 whp on a 100 deg day.

[Forge_55b]

it could really be anything that everyone posted but without gauges its just guessing imo

im sure you know plenty of people that you could borrow some gauges from just to troubleshoot or even get some for cheap at napa

[Addicted2Kouki]

Originally Posted by socal_kouki

Your problem is osbviously cooling. Get some fans/radiator/or cooler thermostat... any of those would bump your cooling. Intercooler will help but with 7psi you're going to lose noticable power.

I read another good tip up there about your oil. Sounds like you've got enough homework to get this on it's way.

Thank you captain obvious.
I already have an aluminum radiator with fans.
Thermostat is on its way next time I get some money.

FMIC Intercooler is going in soon.

I was wondering what exactly caused it
and already got that answer.
I was also wondering what I could do about it
OTHER than a front mount.

[bo2o]

put in a wide band on it and youll find out forshure if the heat is make your car run worst in the heat.

it should be richer wen hot i believe. or the other way around iono
get wideband and safc.