Hey Guys,

Took the car to the Dyno on the weekend. Pulled some relatively unimpressive numbers! All I have is a K&N and removed silencer w/180 thermo.

The car pulled a peak of 148.7hp and 184.5ft-lbs.

It was definately lower than I expected! But there was an automatic SHO there that threw down only slightly higher numbers. So I wasn't overly suprised after I saw his run!

I'll dyno the car again after the Stage 2 Jet Chip and exhuast! We'll see what she can do yet!

Let me tell you how funny it felt driving straight onto the dyno rather than backing on! Ohh and I kept saying "rear wheel horsepower" when I told people! LOL

Dave

Something is really wrong with the dyno, or really wrong with your car. You should be putting down about 200 on the ground. 225+ at the crank.

I agree with Will on this one. Most of the M62 SC cars put out between 170-190 at the wheels, depending on age. Crank HP is what the automakers advertise and for yours it'* 225 (Series I). I'd go somewhere else if you try it again. What kind of mileage are you getting? If it'* low, you might want to look at replacing the cat and O2'*. A blocked cat will drag you down quick!

Comp is dead on, too. I've had all these problems. Amazing what a few parts changes can do.

Hey Guys,

Yeah I know the numbers are low but not completely unreasonable. Automatic transmissions suck GOBS of horsepower! The 355 in my truck made 325hp on an engine dyno and then when we dropped it infront of the 700R4 it made only 232hp at the wheels.

I am a little concerned about why I am a little lower than expected but I honestly was only expecting aroung 165hp!

So you guys think I could have a bad O2 sensor or plugged Cat? How do I know for sure?

UGGHHH I miss the truck!

Check out the last question in the FAQ at the dyno that I went to

http://www.dynomotive.ca

it gives a brief explanation of why automatics lose so much!

Anybody else have real dyno numbers for a stock SSEi?


Dave

Theres something wrong with the 700r4. you should not be losing 100 hp thru an auto tranny. if you go with a 20% loss throughout the entire drivetrain (which is normal for an auto), you would still end up with around 260, maybe a little less if you have a loose torque converter. id definitely check into that. anyways, anyone know where i can find a tranny for my 95 SSEi?!?! that bitch blew up 2 weeks to the day after my warranty ran out... go figure

Manuals tend to lose between 13 and 15 percent of their hp and automatics between 17 and 20 percent.

Swap out the oil in the engine and the tranny for synthetic products from amsoil or redline and see how much extra hp you can get.

I have seen one dyno run with a Buick Grand National T-type that had all the fluids, engine, auto tranny fluid and gear oil, changed out to synthetic and picked up almost 50 hp at the wheels.

That is a higher then usual but I have seen some motors make between 5 and 10 more hp on an engine dyno by switching to synthetic.

WARNING! It could be really bad if you put synthetic in the trans. I've heard the 4T60 and 4T65 slip with the extra slippery synthetic trans fluid. I wouldn't even risk it, because the 2 I heard about never got rid of the slip, even after flushing. I'll try to find where I found that. I do remember reading it, though. Jr may be able to shed some more light on this.

The only problems I have ever hear relating to transmissions and synthetic fluid is in the Borg Warner 6 speeds that go in the viper/vette/F-Bodies.

Sometimes the synthetic is so slick that the synchros won't line up and you will have lots of trouble shifting gears.

I could see there possibly being a problem with putting synthetic in an high mileage transmission because of the increased clearences though. Many cars now are coming with synthetic tranny fluid from the factory and the transmissions are sealed. These are essentialy life time fill applications.

Let us know which cars are coming with these sealed trannies so we don't buy them! I don't trust crap like that. I want control over when and where my cars are serviced, NOT the manufacturer! I can burn tranny fluid up in a weekend of hard racing,, what good does a sealed one do me?

Here'* the FAQ guestion from that website:
My automatic equipped vehicle is showing very low HP numbers....why?
Automatic transmission and non lock-up torque converters "use" a lot of power! We are finding anywhere from 15 to 25% less power then a vehicle with a similar engine but with a standard transmission. Superflow did a test in fact where they put a motor on an engine dyno, and then put it in a car and did a rear wheel horsepower test with an auto trans, and non lock-up converter, and lost 26% of their power!

Did they do that with a stick, too? Doesn't sound like it. I agree with Azwed on the loss numbers. This is also why gas mileage is different between the two. That, however is changing. Most trannies today use lock-up TC'* because of overdrive. I have a 700R4 strapped to my Caddy 502 and it works just fine. I expect an 18% drop from crank HP to wheel HP. They are two separate numbers, both equally important.