TECH TALK - ask your technical car questions

boganbusman · Post by **boganbusman** » 30 Jan 2005, 02:52

Recently I've noticed a fair few people asking questions about cars, like how do turbos work, and stuff like that. So I thought it might be a good idea to make a thread where you can ask your questions about cars.

There are plenty of people here who know lots of stuff about cars, so ask your questions and they should get answered. Just ask anything, it doesn't matter how stupid it might seem.

Cya later.

PSZeTa · Post by **PSZeTa** » 30 Jan 2005, 03:10

http://forum.nfsunlimited.net/viewtopic.php?t=2642

Andre_online · Post by **Andre_online** » 30 Jan 2005, 03:17

LOL, it's even stickied...

boganbusman · Post by **boganbusman** » 30 Jan 2005, 09:46

It's not the same thing FFS. That thread is when you need some parts or something, not general 'how does it work' car questions.

TheStig wrote:anything related to buying car stuff

So that's why I made this thread.

master m · Post by **master m** » 30 Jan 2005, 14:28

I don't have any questions about "Tech Tallk", but I'll post a link of a website which has the answers to alot of car-related questions

http://auto.howstuffworks.com/

MarlboroMan · Post by **MarlboroMan** » 01 Feb 2005, 06:59

dear boganbusman,

i am a poor man that like to mod car, and i am looking for a Apex-i S-AFC II to fit on my charade(swap 4E-FTE). i wonder that you have any idea about it

question :
if my ECU got a fuel cut at a particular speed, does the SAFC II can bypass the fuel cut (since the SAFC got a basic fuel map function)??

thanks

Sweeper · Post by **Sweeper** » 01 Feb 2005, 12:49

Yeah, this is useful. LOL, it isn't that long ago since I didn't know what a camshaft did in a piston engine, heck I didn't even know what an intake manifold were

boganbusman · Post by **boganbusman** » 01 Feb 2005, 13:43

MarlboroMan wrote:i am a poor man that like to mod car, and i am looking for a Apex-i S-AFC II to fit on my charade(swap 4E-FTE). i wonder that you have any idea about it

question :
if my ECU got a fuel cut at a particular speed, does the SAFC II can bypass the fuel cut (since the SAFC got a basic fuel map function)??

If you're getting an aftermarket ECU, the fuel shouldn't cut out unless you program it to do that.

I don't know what exactly a SAFC-II is, so you should really talk to an expert about it (i'm no expert). Or there might be someone else around here who can help you out.

But now I've got a question for you: Why are you modding a Charade?

EmptyWords · Post by **EmptyWords** » 02 Feb 2005, 00:26

so whats a "cat"?

boganbusman · Post by **boganbusman** » 02 Feb 2005, 03:46

'Cat' is short for catalytic converter. It's usually placed right after the headers in the exhaust system. It contains materials inside it that 'filter' most of the bad stuff out of exhaust fumes. Without one (or two) of these, you car cannot be roadworthy, because of emmision laws.

Some people leave them out because they restrict the airflow of the exhaust, thus reducing power. High-flow cats are available, but they still restrict power a fair bit.

They look like this:

Hope that helps

EmptyWords · Post by **EmptyWords** » 02 Feb 2005, 04:06

ahh, i see, thanks for the explanation, it helped

MarlboroMan · Post by **MarlboroMan** » 02 Feb 2005, 04:50

well i think the Apex-i S-AFC is somewhat a small electronics "stack" up to the ECU and alter the reading value in the ECU. it is doesn't work as stand alone ECU. If convert, its around 400 aussie for a piece, V-AFC is basically the same thing, but it can define the VTEC activation rpm function (only VTEC i think, not applicable for other variable valve timming valve lifting system)

i think for this price and such a product its quite worth it.

why i am modifying a charade ?
1)because my parents gave me one.
2)i am poor

boganbusman · Post by **boganbusman** » 02 Feb 2005, 08:32

MarlboroMan wrote:why i am modifying a charade ?
1)because my parents gave me one.
2)i am poor

Still ,a charade doesn't really have much potential. I understand that you're poor (so am I), but you're probably better off investing your money to buy a better car.

Anyway, I think I understand you question a bit better now. You want the SAFC thingy to prevent the ECU from cutting the fuel, correct?
I looked it up and to me it seems like a pretty fancy unit (It's got a VFD display monitor and stuff like that). From what I've read, it does seem like you can prevent the ECU from cutting fuel at a certain RPM.

The new Super AFC-II can save two data setting from data collected with respected to air flow adjust rate, throttle duration, engine RPM, etc

Also, what sort of power gain are you expecting to get from this thing?

MarlboroMan · Post by **MarlboroMan** » 02 Feb 2005, 10:44

well i'd be happy to have it push to 130 wheel horse with the 4E for a 700kg car.

boganbusman · Post by **boganbusman** » 02 Feb 2005, 10:46

Well good luck with that.

Be sure to post your car in the 'what do you drive thread' when your done.

Sweeper · Post by **Sweeper** » 02 Feb 2005, 12:00

BTW, I was pondering about something I heard a while back.
I have checked with my regular car sources but nor they or I can find out what the heck a turbo uppipe is...

Do you know what this "uppipe" is? I know what the downpipe is, but never heard of the uppipe, if it even exists.

^Sparco^ · Post by **^Sparco^** » 02 Feb 2005, 17:38

Is the stock rims size of a car always the better size?

If not: Are the car manufacturers stupid?

Thanks in advance.

boganbusman · Post by **boganbusman** » 03 Feb 2005, 09:22

Sweeper wrote:Do you know what this "uppipe" is? I know what the downpipe is, but never heard of the uppipe, if it even exists.

I've never heard of an up-pipe either. If it does exist, then it's probably just the pipe that goes from the turbo compressor to the intercooler/manifold.

^Sparco^ wrote:Is the stock rims size of a car always the better size?

I'm assuming that you're not talking about 21" or bigger wheels . . .

Wheel size is ultimately unimportant unless we are talking about open-wheeled race cars.
Bigger or smaller wheels will not really effect handling. But, it will adjust the speed of your car. Bigger wheels will give you the same effect as taller gearing, and will also give you an incorrect speedo readout. But of course you can adjust your gear rartios and speedo to make it normal again. Smaller wheels will of course mean the opposite.

But for manufacturers, there are two main resons why the stock wheels are relatively small:
1. They are much more expensive (bigger tyres are also more expensive)
2. Most customers don't like the look of humungous wheels.

So no, manufacturers are not stupid. The only thing that really matters about wheel size is the width and offset of the wheels.

And one last thing: If you're going to fit bigger wheels to your car, remember to lower the suspension a bit, because your car will be slightly taller. And remember to adjust the speedo, and the gearing as well if you feel it's necessary.

Hope you understand that (it's sorta hard to explain)

909 · Post by **909** » 03 Feb 2005, 10:02

so... a quick question for the techies

...

what exactly is "blueprint the block" ?

i mean in real life not in the game. what should be done to the engine and whats the result (performance/sound)?

MarlboroMan · Post by **MarlboroMan** » 03 Feb 2005, 16:39

but when bigger rims comes in i think you are able to fit yourself bigger tyres (width of the tyres especially), and i bet you are able to fit bigger brake calipers and disc too. i think else than good looking and what Boganbusman said, it will improve grip, since the contact surface between the tyres and road increase, and for the bigger/better of brake calipers and disc installed, stopping force.

thats what i think but i dunno whenever it is correct.

2gTSiAWD · Post by **2gTSiAWD** » 03 Feb 2005, 20:13

Sweeper wrote: Do you know what this "uppipe" is? I know what the downpipe is, but never heard of the uppipe, if it even exists.

It could be serveral things. A Turbo really doesn't have a "Up-Pipe". The pipes/tubes/what ever you want to call them that run out of a turbo are of the following.

-Intake Pipe on the Inlet side of the Turbo that has the Air Filter

-On the Exhaust side of the turbo is the o2 Housing (if turbo is equiped with one) then goes into the Downpipe.

-The J-Pipe. As some may call it is on the underside of the Turbo. This pipe goes from the Turbo and to the Intercooler.

-Another possibility what a "Up-Pipe" may be is the Upper Intercooler Piping that comes from the Trottle Body and to the Intercooler. This pipe contains the BOV that releases extra pressures the Turbo makes and releases back into the Intake Pipe of the Turbo or in some cases some people Vent their BOV's into the engine bay.

I have never heard the word Up-Pipe before. Some people call things differently than others. Hope this little info cleared some things up for you.

boganbusman · Post by **boganbusman** » 04 Feb 2005, 05:47

MarlboroMan wrote:but when bigger rims comes in i think you are able to fit yourself bigger tyres (width of the tyres especially), and i bet you are able to fit bigger brake calipers and disc too. i think else than good looking and what Boganbusman said, it will improve grip, since the contact surface between the tyres and road increase, and for the bigger/better of brake calipers and disc installed, stopping force.

Yeah that's pretty right MalboroMan. Bigger wheels allow for bigger brakes, but smaller brakes are capable of being just a good as larger brakes (albeit at a higher cost).

And wheels can be wide without being tall as well.

It's all about compromise. But at the end of the day, wheel size doesn't make a big difference.

Edit 24/7/06: After learning more about suspension systems etc, I just need to correct a couple of things regarding wheel sizes.

Ideally, a car wheel should be as small and light as possible, to reduce the unsprung weight. Less unsprung weight will allow the wheel and suspension to follow the road surface with much more ease and accuracy, thus giving you better roadholding.
A smaller wheel will also allow the car to have a lower waistline along the quarter panel, as well as less rotating mass which will improve engine response.

@2gTSiAWD: Thanks for the contribution

Drewb99 · Post by **Drewb99** » 04 Feb 2005, 06:55

And certainly don't forget that there's a limit to how low-profile a tire can get. It varies from rim to rim, but there's a threshold where you risk flat-out snapping the rim- so no rubber band tires.

MarlboroMan · Post by **MarlboroMan** » 08 Feb 2005, 05:35

dear 909,

about "blue print the block", i am not quite sure about it,

to me, "blueprint the block" most probably mean that make a plan of the engine block with new spec (such as bigger bore diameter, new material), send it to some cold forge factory to custom forge it as the plan. so the whole engine block is in 1 piece, forge items can take more punishment than regular mold ones.

Post by **TheStig** » 08 Feb 2005, 05:39

I know they blueprint the block on a racing motorbike... but what it exactly does...