Car feels like its slower on a hot.. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Addicted2Kouki · 09-03-2008, 08:53 PM

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 · 09-03-2008, 09:25 PM

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* · 09-03-2008, 09:36 PM

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

projekt_s13 · 09-03-2008, 09:39 PM

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

tt99ol · 09-03-2008, 09:41 PM

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 · 09-03-2008, 09:42 PM

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 · 09-03-2008, 09:51 PM

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 · 09-03-2008, 10:08 PM

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 · 09-03-2008, 10:20 PM

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 · 09-03-2008, 10:28 PM

Quote:

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.

Quote:

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!

Quote:

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..

Quote:

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.

Quote:

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.

Quote:

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 · 09-03-2008, 10:33 PM

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 · 09-03-2008, 11:26 PM

Quote:

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 · 09-03-2008, 11:30 PM

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 · 09-03-2008, 11:59 PM

Quote:

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 · 09-04-2008, 12:05 AM

Quote:

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 · 09-04-2008, 12:11 AM

That's where it's at.

illvialuver · 09-04-2008, 12:20 AM

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 · 09-04-2008, 12:31 AM

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

Addicted2Kouki · 09-04-2008, 12:33 AM

Quote:

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 · 09-04-2008, 12:34 AM

Quote:

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 · 09-04-2008, 01:05 AM

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 · 09-04-2008, 02:58 AM

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 · 09-04-2008, 03:09 AM

Quote:

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 · 09-04-2008, 03:50 AM

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.

09-03-2008, 09:36 PM	#3
njd07 Premium Member Join Date: Jan 2004 Location: canada Age: 35 Posts: 644 Trader Rating: (14) Feedback Score: 14 reviews	lol 7psi...im running 12 on my t25 and that feels slow. so use to having 16psi on a t28. __________________ s13 parts fs:http://www.zilvia.net/f/showthread.php?t=193416 sr parts fs: http://www.zilvia.net/f/showthread.php?t=193399 s14 parts fs:http://www.zilvia.net/f/showthread.php?t=193420 180sx part out http://zilvia.net/f/showthread.php?t=203711

09-03-2008, 09:39 PM	#4
projekt_s13 Post Whore! Join Date: Jul 2005 Location: Chico/Pittsburg, CA Age: 35 Posts: 2,801 Trader Rating: (5) Rides Gallery: projekt_s13 Feedback Score: 5 reviews	I find it harder to run on a very hot day, but on a cool day i can run really fast. __________________

09-03-2008, 09:41 PM	#5
tt99ol Zilvia Addict Join Date: Jan 2005 Location: quartz hill CA Age: 34 Posts: 644 Trader Rating: (8) Feedback Score: 8 reviews	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 __________________ Need automotive work done in the antelope valley? Ask me how i can help.

09-03-2008, 09:51 PM	#7
murda-c Post Whore! Join Date: Jan 2007 Location: Montgomery County, MD Age: 33 Posts: 3,197 Trader Rating: (1) Feedback Score: 1 reviews	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. __________________

09-03-2008, 10:08 PM	#8
DirtyS14 Zilvia Member Join Date: Sep 2007 Location: Odaroloc Posts: 190 Trader Rating: (2) Feedback Score: 2 reviews	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. __________________ S14 240SX aka "The Dirty S14" fizzerkart.com/s14.html

09-03-2008, 09:25 PM	#2
JVD Nissanaholic! Join Date: Feb 2005 Location: Alberta, Canada Age: 32 Posts: 1,820 Trader Rating: (0) Feedback Score: 0 reviews	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.

09-03-2008, 09:42 PM	#6
renegade_ewok Zilvia Junkie Join Date: Oct 2007 Location: NYC Age: 33 Posts: 450 Trader Rating: (0) Feedback Score: 0 reviews	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.

09-03-2008, 10:20 PM	#9
s14jesse Zilvia Junkie Join Date: Jan 2008 Location: highland (909) Age: 32 Posts: 410 Trader Rating: (6) Feedback Score: 6 reviews	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

09-03-2008, 10:33 PM	#11
murda-c Post Whore! Join Date: Jan 2007 Location: Montgomery County, MD Age: 33 Posts: 3,197 Trader Rating: (1) Feedback Score: 1 reviews	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. __________________

09-03-2008, 11:30 PM	#13
murda-c Post Whore! Join Date: Jan 2007 Location: Montgomery County, MD Age: 33 Posts: 3,197 Trader Rating: (1) Feedback Score: 1 reviews	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. __________________

09-04-2008, 12:11 AM	#16
ESmorz Post Whore! Join Date: Oct 2007 Location: It Looks Like A Dong Posts: 6,902 Trader Rating: (2) Feedback Score: 2 reviews	That's where it's at. __________________

09-04-2008, 12:20 AM	#17
illvialuver Post Whore! Join Date: Oct 2006 Location: M-A-R-S... MARS BITCHES Age: 38 Posts: 5,065 Trader Rating: (35) Feedback Score: 35 reviews	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.

09-04-2008, 12:31 AM	#18
projekt_s13 Post Whore! Join Date: Jul 2005 Location: Chico/Pittsburg, CA Age: 35 Posts: 2,801 Trader Rating: (5) Rides Gallery: projekt_s13 Feedback Score: 5 reviews	ahahaha intercooler intake. My friend did that on his DA integra, made the car lagg and run like shit. __________________

09-04-2008, 01:05 AM	#21
blu808 Post Whore! Join Date: Dec 2002 Location: Campbell, Ca Age: 38 Posts: 5,010 Trader Rating: (3) Feedback Score: 3 reviews	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. __________________

09-04-2008, 02:58 AM	#22
Forge_55b Zilvia Junkie Join Date: Jun 2007 Location: OC Age: 39 Posts: 414 Trader Rating: (2) Feedback Score: 2 reviews	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

09-04-2008, 03:50 AM	#24
bo2o Zilvia FREAK! Join Date: May 2006 Location: 626 socal! Posts: 1,315 Trader Rating: (7) Feedback Score: 7 reviews	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. __________________ fS! *vlsd ! slim fans ! hid kits ! lug nuts !* http://www.zilvia.net/f/search.php?d...earchuser=bo2o ^^^click^^^

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