afireinside1582

ok... so if i rule out the ecu retune, how many horses do you think this would add to my 145 bone stock cobalt?

Roadrunner

im gonna guess you will be close to 195-200bhp, another member on here had a few less mods and pumped out those numbers. consider cams, they would prob bring that number up a bit. stage 1 requires no reflash.

im gonna ask the question since i dont think anyone else will....if we actually had the retune software from hp tuners, what would be the diff between hooking up a laptop and tuning and using a fmu?

CobaltCoupeCrazy

iTrader: (1)

Nology Silver spark plugs are resistorless. They allow full spark energy to be transmitted to the plug gap. Also, silver is the best conductor. For more information: http://nology.com

I just purchased the coil-on-plug conversion kit. I am going to install the kit which utilizes a remote mounted coil, hotwires, and I have Silver plugs. I got a deal on my kit b/c apparently it is going to be discontinued. It can still be found on a few sites.

shawnbandit

try clicking the link in cobaltjustin's post about the gm performance book they made

NJHK

195-200 BHP? I think far from it...you're talking about a full exhaust upgrade, some plugs and wires (which I wouldn't really advice to make the conversion...) and a simple ECU reflash to change the fuel curve a little bit (by what company btw?). With those modifications, he won't be adding 55-65 Horsepower over stock. This is the type of gains forced induction does...not something with simple bolt ons.

Also, BHP means nothing, WHP means everything.

To answer your question:

The HP Tuners device is more percise as far as letting you change pretty much every perameter and control that your computer has control over. From changing the duty cycle on your injectors to change your ignition timing to change your shift points (if you're an automatic).

With an FMU, it's all done physically, not electronically. An FMU works off of vac/boost pressure and it works on a ratio. It's job is to increase the pressure inside your fuel rail by restricting the return side of your fuel system. FMUs run off a ratio of fuel, the higher the ratio, the higher the fuel pressure per PSI inside your fuel rail. There are all different types of FMUs...some that are single ratio'd (example: 6:1 or you buy one that is 12:1) or you have FMUs like a Cartech FMU that is adjustable from 1:1 to 12:1 ratio.

CobaltCoupeCrazy

iTrader: (1)

He probably doesn't even realize that the car has no wires; it is a coil-on-plug ignition system. I'm only changing my system over to utilize the Hotwires with my Silver plugs.

afireinside1582

...you are correct, i was unaware of the wires. i havent really been into cars until i got my cobalt about a year ago. before that, i had a '92 accord, and i really didnt want to be some punk ricer so i didnt do anything to it. right now im just trying to learn everything i can. i dont want to go F/I or N2O. this is my daily driver that i will be taking to college this fall.

anyways, somebody said something about adjustable cams? or higher compression pistons?

Roadrunner

whp varies with bhp, whp is easier to get than bhp on an engine. are you going to tell me that an engine putting out 200 bhp could have less at the wheels than an engine with 150 bhp? with simmilar transmissions i dont think so
where the heck is traviskearny, he had 191bhp on his cav without nitrous, i will post the link when i can find it
sorry but i will come back with a reply to the fmu vs a retune tomorrow when im sober.
nitey nite

IonNinja

actually I believe he dynoed at 150whp and even on a 20% drivetrain loss (auto tranny) thats about 180 crank HP.

the reason I believe NJHK said bhp means nothing is because you aren't actually putting that power down to the ground...

NJHK

You understand what BHP is right?

So to your comment of "whp is easier to get than bhp on an engine" makes no sense. Brake Horsepower is power generated by the motor...wheel horsepower is power that's actually making it to your wheels after all the drivetrain loss.

Of course a car with 200 BHP is going to have more WHP than a car with 150 BHP if they have similar transmissions (same amount of % drivetrain loss, same amount of gears, similar gearing ratios). No one is arguing this. I think you're totally missing my point. You're telling someone they are going to gain 55-65 BHP from just a few bolt ons. If it was that easy, everyone would be running mid-high 14s in the 1/4 with about $1000-1200 spent.

NJHK

Exactly. If your wheels don't see the power, it's power wasted.

What work does he have done? The reason I'm asking is because I know that the auto tranny stock w/the 2.2L dynos around 118-120 whp.

IonNinja

takin directly from his sig (traviskearney):

2005 Chevrolet Cavalier
2415 lbs.
150.4whp/222.0whp
AEM Cold Air Intake
Airaid TB Spacer
DC Sport Ceramic Header
Catback 2.5" Into Dual 3" Out NOPI Carbon Fiber Exhaust
Zex Wet Kit
18" Konig Tuner II Rims
18" Ventus HR II Tires
Dropzone 2" Lowering Springs
Tokico Sport Struts
Tokico Sport Shocks
Tokico Front And Rear Tower Braces
VIS Carbon Fiber Hood
Tsudo Carbon Fiber Spoiler
Second OEM Deck Lid For Custom Spoiler Install
AVS Smoke Headlight Covers
Custom 1200 Watt Pioneer Stereo System
15% Window Tint

N/A his dyno sounds a little high IMO but who knows...

Roadrunner

https://www.cobaltss.net/forums/show...ight=2.2L+dyno

i understand what BHP is, read my post. reread my post and post another two definitions please. if you want to make it WHP, fine, i will guess on an auto 155-160 with cams, hows that?

bhp - losses = whp does it not Adam?
assuming 20% lost,
bhp - 20%*bhp = whp
so whp would vary with bhp would it not Adam?

so lets say he had 191.4 Bhp rather than 180,
191.4 X .2 (the 20% drivetrain losses) = 38.28hp
191.4 - 38.28hp = 153.12hp

lets say 180hp like posted
180hp X .2 = 36hp
180hp - 36hp = 144hp

check your calculations for losses, but try 188hp for travis (close enough to make what he says is true IMO), then remember that the cobalt 2.2 has 5 more hp and i thought these came from not having a power steering pump on the engine.

ok well then go get your engine dynoed for bhp instead of whp. does it make sense that its easier to set up the entire car on a dyno, rather than pull the engine or do you disagree?

someone please post typical drivetrain losses for auto vs manual, this number has been varying so much lately. i have always assumed 20% for auto and 13% for manual

IonNinja

just to make it easier I use 15% for manual and 20% for auto.

you're also coming up with a different number because you are taking bhp and then subtracting it by 20%. Since we technically don't know crank hp and only wheel hp, I added 20% to the wheel hp figure and it gives you a different number.

150WHP + 20% = 180WHP

edit:
and for an auto transmission that seems awefully high anyway...because you figure on a manual tranny you're going to dyno even higher with just bolt ons. Thats like a 35-40WHP gain off basically intake/header/exhaust.

NJHK

The way you worded your sentence wasn't to say that it's easier to FIND OUT your bhp...that's why I said it made no sense. If you re-read what you wrote, you made it sound like BHP is easier to make (as in gain from modifications) than it is to make WHP. That's why I asked if you knew what BHP was.

NJHK

I agree.

CobaltCoupeCrazy

iTrader: (1)

The way you illustrate that calculation doesn't account for a 20% drivetrain loss from BHP. You have to find what # (bhp) - (# x0.2) = whp. 180 x 0.2 = 36 resulting in 144 whp. 188 - (188 x 0.2) = 188 - 37.6 = 150.4

IonNinja

and if you don't know bhp?

I'm not sure what the difference in my math and yours is...if I subtract 20% from 188HP I get the same number as you do.

the point I'm making is that when you jump on a dyno you don't get bhp figures, you get whp figures so you have to add the % of drivetrain loss to your whp figure to get your bhp number.

NJHK

I don't really see the point in finding out your BHP anyways but to each is own.

CobaltCoupeCrazy

iTrader: (1)

I know that. I'm just saying you can't add 20% of the whp figure to get the bhp figure. You don't get the correct result that way; that's not how it works. Gotta use your algebra.

In other words:
WHP is 80% of BHP (BHP is 100% and 20% less is 80% of BHP = WHP)
WHP/ 0.8 = BHP

So use this equation:

WHP / L = BHP
where WHP is obtained on a chasis dyno
L is 100 - % drivetrain loss expressed as a decimal ie 15% loss = 100 - 15 = 85 = 0.85 in equation

Does that help??

IonNinja

actually no

because when I do that calculation I get a smaller number than my whp figure...just like if I started with a bhp figure and was trying to figure out my whp. Not the other way around like it should be.

And again if I do hp x 0.8 = hp I still get the same result as hp - 20% = hp

I can understand how adding a % to a figure to find out bhp may come out different but when working with an already established bhp number and just subtracting a percent from that to calculate whp...the numbers seem to be right on.

CobaltCoupeCrazy

iTrader: (1)

My goodness!!

I so screwed that up when I wrote it.

Here is an example with #'s:
180BHP - (180x.2) = WHP
180 - 36 =WHP
1144 = WHP

144WHP/.8 = BHP
180 = BHP

You are supposed to divide by the .8!! My fault I'll change the equation. LOL Had it right wrote it down wrong.

But to show you the difference:
144 WHP + 144 *.2 = 172.8BHP This is why you can not just take 20% of the whp and add it to whp to get bhp.

Roadrunner

ok misunderstanding, i understand, but as you can see i did say whp is easier to find than bhp

Roadrunner

you have 20% losses in your engine horsepower from the drivetrain, so its bhp - 20% of bhp = whp

and if you set up the formula correctly to solve for bhp it should look like this
bhp = whp/(1-0.2) again assuming automatic.
might sound to you but it sounds right to me

Novajoe

so basically he has:
CAI
short tube header w/2.5" cat back
zex shot(what size?)
and a tb spacer...

where the hell did he pick up all the hp from?Off the bottle he might get an extra 10whp being generous... I can't see with his mods him being at 150whp off the bottle. For that matter over 200 on the bottle without a HEALTHY shot... I'm assuming the 05 cavaliers had the same powerplant and drivetrain as the cobalts?