I talked to the guy and he said it was an automatic and the guys at the dyno were like your losing an additional 10% of power because of your transmission.
Too bad when I dyno at 260 with minimal modification and he's only at 280 (+/-).

 

So, the moral of the story is, if you have an automatic, don't expect a whole lot with mods.

 

well of course that's what they said, look who they work for!

 

i still think thats bs. they ve been around long enough to be honest not to bs us

 

i agree that it's bs. but to be about 70hp off from what everybody else gets? i know it's an auto and that it robs you of power, but that much? sounds weird to me...

 

Now you're spelling you're rong.

 

True, an AT will always put down less RWHP than an MT all things being equal. Typical loss for a 6MT is 15-20%, where a 5AT is 25% or more. So, with my mods I dynoed at 231 HP with a 5AT @ 231/.75= 308 crank HP. This is 48 more than claimed by Infiniti. So the mods do work for the autos, and what matters anyway is how the car feels and the track times. Autos can and do beat manuals with equal crank power (less RWHP) due to more precise shifting.

 

straight line, yes...but throw some turns in there, and it's a different story

 

Mainly due to the LSD that the manuals come with. My biggest regret, but can be remedied with a Quaife. I will do this prior to any FI in my future.

 

And yet here's another way to look at it....

Stock Gs have been base lined at anywhere between 220-240 at the wheels. (I've seen the sheets from various owners) All depending of if it's a Friday motor or a Wednesday motor Every engine will dyno a different amount. When manufactures post their "claimed" hp numbers they most likely use the numbers from the best engine that was dynoed out of a group of engines.

For example.....that dyno run with the auto G35 with the Stillen supercharger, exhaust, and intake was 288rwhp. Assume he base lined and his car put down 220 rwhp. 220*1.25(drive train loss) and you get 275 crank hp. With the SC and other mods he has 288rwhp. 288*1.25=360 crank hp...that's an increase of almost 100hp at the crank and about 65rwhp. This was for a stage 2 kit at 6.1psi. Not bad in my opinion. Even if his car did put down more than 220 base those numbers are still a good increase. Keep in mind all engines make a different amount of power.

Now take the same car....with maybe a 235 rwhp base line because someone at the factory was having a good day, not being Friday since people don't care what they do at work as long as they make it out at 5pm to enjoy their weekend That same car with a MT will make 235rwhp*1.18=277crank hp, about the same crank numbers as the AT car. Add the 65rwhp from the SC and you get 300rwhp......just what Stillen quotes in their catalog.

Most people don't realize the amount of power lost through the drivetrain. AWD cars are even more...up to a third!!! Those numbers on the dyno, which is a dynojet if I remember correctly, are right where they should be.

sean

 

you're right sean, that cars will dyno different numbers, on different dynos, on different days, etc, etc, etc. that's why some believe you should try and dyno on the same dyno (not just the same type of dyno), on similar weather conditions.

but if you look at the stillen website regarding the hp numbers, you could see that it's a little off (around 25rwhp).

 

The crank vs RWHP that people are quoting have a higher variance than I always thought... isn't the crank roughly 15% higher than RW?... Also, you said your 231 dyno = 308 at the crank, that's more than 33% higher ~ I'm not trying to create controversy, just want to make sure I'm understanding correctly 'cause like everyone else, I'm always chasing more horsepower! My last dyno was 241 (not nearly enough for me!)

Also I wish more people would post torque gains and how to get ‘em… DaveO is the only one I’ve talked with that agrees it’s valued.

 

Torque gains are all I care about. That is what most of us use anyway. Stop light to stop light speed is ALL torque.

Some people get caught up in the horsepower talk, but forget about torque.

This is why I never wanted to go with test pipes. I refuse to do anything to lose low end power.

If I'm going to gain horsepower with a mod, but lose torque.....I won't do that mod.

All this to say, I wish they would post torque numbers too.

 

maybe Stillen used a M/T on the dyno which would explain the extra loss in rwhp in the auto car. not trying to argue with anyone, just trying to figure out the cold hard facts and clear up some info.

Torque is great. My engine makes 50 more lbs of torque than hp at the wheels (230 vs 280). You can definately feel the rush of torque when my turbo spools.

sean

 

i'm not sure which car stillen used. i have yet to see a large company that shows the details of their dyno numbers. i too am trying to figure out the info, but at this point, who knows.

isn't the rush great ! a turbo car scares me sometimes!