Five.Point.Oh

Ok, so I have a 2005 GT 5-speed with a CAI and SLP Loudmouths (muffler deletes). When people ask how much hp it has, I say with all the mods like 330 (stock is 300). Now, when I told a group of car guys that, they laughed at me and said, "Yeah, right! With those mods, that car has only 310!" Of course, dynoing it will tell me for sure, but I can't. So, the question is: Who has the better projected hp, me or them? I really think they're just being silly.

70MACH1OWNER

You are probably very close to being correct. Of course there is 2 kinds of horsepower guys talk. At the crank or to the rear wheels. The stock horsepower rating of your 05 is 300 at the crank which is around 275 to the rear wheels. The CAI will give you up to 25-30 at the crank. The mufflers are really worth nothing. If I had to guess your car in 325 crank or 295/300 at the rear wheels.

muscledom

If you haven't had it tuned you've gained nothing. So you're at like 265rwhp.

Kevin509

+1

CAI without a tune is good for maybe a single digit hp gain, and really any exhaust mods behind the cats are sound mods only.

Add an offroad midpipe and a tune and you'll be at the numbers you want.

Five.Point.Oh

I have tuned it, the CAI It has required it.

Kevin509

Well in that case you're probably in the 315 crank hp range I'd guess. an offroad midpipe will put you up in the area you want to be. But will be really loud with your loudmouth axlebacks...

muscledom

Then you're probably at like 285rwhp then

Glenn

Most intakes with a tune that I have seen dyno's on were in the + 25hp to + 28hp range and the dyno's I have seen for mufflers were any where from +3 to about +9 hp gains. Sooooo starting out at 300 rwhp and adding the intake I would guess +25 losing the mufflers may only be adding noise and possibly losing a few lbs of tq I would have to search around the net to see what I find for the loud mouths. My unprofessional guess would be 325 at the rear wheels. You will always find someone that wants to dissagree with you. Maybe in the future tell them you only gained 5 or 10 hp and the will want to argue that heck no you gained more than that.

retfr8flyr

With a CAI and tune and a manual I would say about 275-280 on the dyno, depending on the outside temps. Stock you're around 255-260 on a 2005. When my 2006 had Kooks headers, CAI and tune with my automatic, it only made 270 on the dyno. The manual has much less drive train loss then an auto does.


Earl

05YellowGT

Here's the dyno sheet from when Steeda installed my CMDP with the before and after results. The before is with Steeda's UDP , axile back exhaust and CAI with tune.

ford20

What does the A&E CAI look like? I don't believe I have heard of it before.

But you are looking at 270-280 at the wheels with those mods. For me when ever I talk about HP numbers I usually use RWHP rather then crank HP but what your engine makes is somewhat simple to calculate. The consensus is that your engine HP is roughly 15% of your RWHP for a manual and about 20% of an automatic due to parasitic drag loss.

lindertw

2005 GT 5spd manual
K&N cai, OEM h-pipe w/cats, FRPP shorty headers, FRPP GTA mufflers, 3.55 gears, no tune, 93 octane in the tank
12NOV11 9am, 45 degF, 30.1 in Hg, 59% humidity
295rwhp / 316rwtq (STD correction)



***added 93 octane tune and Steeda UDPs
07JUN12 1:30pm, 75 degF, 30.03 in Hg, 49% humidity
302rwhp/317rwtq (STD correction)

Taxman72

You might have 275 at the wheels. That's the only HP that matters.

lindertw

Turns out there's a negative horsepower test that you can run on a dynojet to find out the real parasitic loss (vice the estimates of 15%-20%).

from the dynojet manual (section 4-8):

Negative horsepower can measure how much power is absorbed by your drive train and other parasitic losses (transmission, drive shaft, and tire friction). To graph drive train loss simply perform a roll-on test.

1. Follow steps 1-8 for “Making a Run” on page 4-3.
2. At redline, push the clutch in (manual transmission) or put the vehicle in neutral (automatic transmission). Allow the vehicle to coast to a stop.
3. When the drums are no longer, turning press the green sample button.
4. View the graph with negative horsepower enabled. This will display a positive and negative horsepower graph.

The amount of horsepower displayed below zero is how much power is being absorbed by the drive train at a given speed. Drive train losses can be visualized as the negative horsepower area of the graph shown in Figure 4-6.



I plan to ask my tuner to try it during my next dyno visit.