Got my TT dynotested today.

 

It was measured 241 bhp at the wheels and 423 NM torque.

 

I actually was not expecting more power, think a saw a post somewhere saying they are around 240 at the wheels.

 

The car is standard got 9 psi of boost.

 

I am going to remove the cats, put in a K&N filter and a pair of boost jets and then test it again.

 

I will post the results.

yours is obviously an autobox man then, i stand to be corrected though. as these loose more power than the manuals. mine ran 276bhp at the wheels standard.

 

kings langley Z dyno day.

I know this has been done to death but I still dont understand it.

 

An auto transmission is more lossy but if its tested in overdrive locked out it is in 1:1 ratio through the autobox and also has its torque converter clutch locked up so it has no autobox losses as such in that situation. It should therefore have about the same transmission losses as a manual with the difference only being in the differential which is a different ratio in an auto.

 

So what are the normal transmission losses? I thought around 40 - 50bhp? but what do tests say?

 

How accurate are dynos? I heard they were often "adjusted" so as not to hurt the pride of the hot hatch brigade.

 

My mates upgraded STI Scooby showed 300bhp on the engine with 100 lost in the 4wd transmission I guess meaning 200 left at the wheels.

 

So Lack300, if your standard ran 276 at the wheels it suggests at least 320 at the engine which is much more than the stock supposedly 280.

Originally posted by WillieO

I know this has been done to death but I still dont understand it.

 

An auto transmission is more lossy but if its tested in overdrive locked out it is in 1:1 ratio through the autobox and also has its torque converter clutch locked up so it has no autobox losses as such in that situation. It should therefore have about the same transmission losses as a manual with the difference only being in the differential which is a different ratio in an auto.

 

So what are the normal transmission losses? I thought around 40 - 50bhp? but what do tests say?

 

How accurate are dynos? I heard they were often "adjusted" so as not to hurt the pride of the hot hatch brigade.

 

My mates upgraded STI Scooby showed 300bhp on the engine with 100 lost in the 4wd transmission I guess meaning 200 left at the wheels.

 

So Lack300, if your standard ran 276 at the wheels it suggests at least 320 at the engine which is much more than the stock supposedly 280.

well the thing is 280 is a jap figure from the factory to comply with Japaneese regulations, so its not what the engines really run at.

 

The general concensus of the dyno day we did was that Autos were down on power to Manuals. and since alot of cars were tested on the same dyno on the same day i guess it takes out the fact of how accurate one dyno is to another ect, because they all give different figures.

 

but 12-15% drivetrain loss was the given figure we had.The guy who ran the dyno (who was a race engineer for the Nissan South African Touring car team SAID WAY TO OFTEN PEOPLE BUMP UP Figures on the flywheel and that they were no where near that most of the time)

Who cares anyway ffs? Its WHP that drives the car not Crank HP so ignore the crank figure - it has no use! Possible extra losses could result in an autobox due to the viscosity of the fluid? Just a thought...

 

CheerZ,

 

Andy

Mine was on a different dyno recently and on the rundown test, they estimated the manual transmission loss at over 20% !

Personally I think that dyno is Donald Ducked becuase one of the bearings makes the most unimaginable squealing racket on the run down. Oddly enough it was a similar figure for MR2's and they should definitely have less loss in the transmission because of the transverse engine/gearbox combination.

Originally posted by WillieO

So what are the normal transmission losses? I thought around 40 - 50bhp? but what do tests say?

 

 

You cant say in BHP what the loss is. The best way is %age but even that isnt a true science.

 

4WD will lose about 33% of power from engine to wheels

 

Auto Boxes, from what I hear, lose about 20% and Manuals 15%.

 

But there are ways to make it lose less power. Lighter flywheel, different types of clutch, getting rid of the LSD for a a fixed on, lighter drive shaft. Even down to the condition of the wheel bearings will all make a difference.

 

Like Andy said with the MR2. I know some one with a Turbo on stock power 245bhp. He put on a HKS induction kit and HKS exhaust I think, and dyno'd it and it got 245bhp. 2 mods made it gain back the power lost through the transmission.

 

Stuart

Originally posted by lack300

yours is obviously an autobox man then, i stand to be corrected though. as these loose more power than the manuals. mine ran 276bhp at the wheels standard.

 

kings langley Z dyno day.

 

Not strictly true Tony ;) you quoted an induction kit and exhaust. On the same day I got 251 standard on a manual.

My car is manual and engine output is 270 so the loss is 30 bhp.

 

This is a US car so it is suppose to be 300.

 

There are only 2 dynos here and one of them is in a school and I don't think I can have it tested there to compare the dynos.

martin that is incorrect as the mag added that. as you will know they spiced up the wording not me.

i still to this day has a standard exhaust although now it is decatted with your pipes you sold me. air filter was upgraded with smithys dual intake but only last year (Billing).

 

the lesson is don't belive everything you read.

 

the only thing i can think of is the rolling circumference of the 18"wheels i had on.:D

i would like to see what it is pushing now?...with all the mods.......440...maybe more?...

Finally got my car tested again.

The result was better than I expected.

It is now 290 @ the wheel 310 @ flywheel.

That's 50 bhp for a very simple mod.

Decat, K&N cone and 1.2mm jets.

Viper

How much boost do you get with 1.2mm jets?

 

I take it you are still on a stock ecu chip so could be risking weak mixture at high boost.

I get 11psi of boost.

 

The ignition is 15°, I tried to advance it to 17° but I got det. at full boost.

 

So its very much on the limit right now.

My next step is to get SE chip.