ras62

Not at the wheels on a C4 it won't. Its hard to know what the numbers represent tbh.

cboltster

The number I posted is showing at the wheels. I've gone over it with the dyno team, and they are confident these are accurate numbers. I'm at a loss because this is obviously much higher than expected, but until I hear a reason why this is incorrect I have to believe that this is in fact the numbers my car is putting out.

cboltster

..

ras62

Then congratulations because that means your engine is making around 380 bhp at the crankshaft if we use (an optimistic) drive train loss of 30%.

cboltster

Yeah it doesn't make any sense to me at this point. Short of ripping apart the engine to look at the internals and adding up mod gains, for now I'm going to reluctantly rely on the data provided by a tried and tested dyno shop.

Lorenzoh

cobalt

I would try another dyno and see. There is no way those numbers are accurate without serious mods costing more than $10k.

964George

How about a simple drag race against a stock or slightly modded C4... See how you get on there?

Lorenzoh

cboltster

That's the game plan, unfortunately my city currently only has 1 4wd dyno.

Those aren't the only mods done, exhaust has been done, ecu has been done, intake has been modified. I was just stating that there is a $10,000 (1993 dollars, roughly $17,500 today), engine mod that I have no idea what it includes.

Nylasurf

I am in the middle of a very long build and have had my engine built up from a 3.6 to a 3.8, lots of internal work done but still running Motronic. Just added a 3.8 RS VRAM to the mix and everything associated with that (can't thank the RL community enough to recommend where to look, research and to source parts). For a point of reference, I will update my build thread here shortly with more info, but in today's dollars I am in 4x your $17.5K in parts, labor, etc. and just bench dynoed and tuned at AASCO Performance making at the crank 318.4 hp (6500 RPM) and 273.2 (5400RPM). When I get the C4 Targa together in the next few months, I will throw it on a 4 wheel dyno to see how it compares to the bench. Was told that this bench dyno is stingy so I imagine others may be generous just like wheel dynos. In the end it is only a number that reflects what we feel by the seat of our pants...I can't compare my car to yours or any other unless that motor was tested on the same bench. The only time bragging rights are legit is on the day that we all get together and run our car on a dyno day...same dyno, same conditions, whether it is stingy or generous. Congrats on the strong numbers, hope the seat of the pants measure up to your expectations.

erikerik

ras62

My

ras62

My Unit 11 rebuilt 3.6 C2 with cams, head work, injectors, cat bypass with cup pipe and set up on the rollers gave 282 whp @6300 265 ft/lb @5200. The cams used gave great results, the motor has excellent midrange torgue and pulls strong even down @2000rpm where it makes about 170ft/lb.

A914MAN

I have a new friend that used to have a dyno shop. During his tenure he had 3 different dynos, and kept the one that would consistently show the highest HP numbers the longest. I asked him about that, and his reply was that most guys would prefer optimistic HP numbers over a lower (perhaps more accurate) number, even went on to say he had a few disgruntled guys who didn't like the number they got. He did all American cars though, here in the rural south. You know the old joke; Bubba: "Wanda tell me the truth, tell me you ain't never cheated on me"; Wanda: "Do you want me to tell the truth, or tell you I ain't never cheated?"

An older Porsche buddy of mine says that every HP over stock usually costs between $1000 and $2500 a pony, not sure how true that is, but probably not far off.