How much Power from the 1jz???

[Smokey228]

my 1250kg car with driver, ran 109mph... That equates to about 198rwkw doesnt it?

Cheers,
Jase

[chris davey]

1250kg +60kg driver and 109mph = 185rwkw. my dyno figures are usually down about 2-3%. dyno's are for tuning only though as Dieseltrain said. continue using the same on and you are fine. 1/4mile trap speeds don't lie (unless you back off before the end )

[Smokey228]

No, 1250 with driver and fuel...

Cheers,
Jase

[Stomps]

1250kg +60kg driver and 109mph = 185rwkw. my dyno figures are usually down about 2-3%. dyno's are for tuning only though as Dieseltrain said. continue using the same on and you are fine. 1/4mile trap speeds don't lie (unless you back off before the end )

Hey, just curious about the whole trap speed v hp thing...

how does wheelspin effect the results....

Due to 14kg rear springs in my supra (and some generous right foot action) i could never get it off the line without shitloads of wheelspin....

the car didnt really start accelerating properly for a good 50odd meters from the start line...

obviously this will effect trap speed wont it?

so what effect does this have?

cheers

For the record.. my results were 13.65 @ 108 mph with wheelspin.. so what kw does that give me.. say 1590kg car + 85kg driver..

cheers again..

Stomps

[chris davey]

wheelspin actually increases the mph slightly. it is very technical and lots of debate on the subject but it is generally accepted that the perfect no traction loss run will have slightly less mph than a run with a bit of wheelspin.

So yes a run with wheelspin will artificially increase the "numbers" at the rear wheels but at the end of that day your ET is going to be a whole heap quicker with no wheelspin obviously.

e.g. I have seen quite a few 1j powered cars running 12.9's to 13.0's at 106mph and that is what I predict your car would run with a better 60ft. Actually doing that is a matter of setup and practice. And obviously just because you drop a mph or 2 doesn't mean your car has lost power but the fact that your car has actually spent less time accelerating due to the much quicker launch.

hope that helps
Chris

oh and 231rwkw.

[Stomps]

cheers man, i was just curious..

im not actually into drag racing all that much...good fun, but im setting my car up for drift and track work rather than drag racing... there are 16kg springs and massively stiff swaybars going into the car, which dont exactly help with launches...

ill still take it down the drags once or twice once finished, but i dont expect anything quick..

car should weigh around 1300kg with me in it.. and be making 450ish rwhp...if all goes to plan..

the 231rwkw was pretty close to what i got on the dyno actually.. 313rwhp (233rwkw)

p.s congrats on braking into the 10's too..

Stomps

[chris davey]

no probs. yeah, we all set our cars up for different things. My car would be TERRIBLE with any corners

stats are pretty close on your car hey. stick with that dyno

[Fiver]

When we set up the 2 step launch on my last car we had it set up to give me a small amount of traction loss off the line, I found the car much more predictable largely due to a lack of "bog" of the line.

For me 60 footers were better with a tad of spin, probably something to do with a tony engine and a biggish turbo.

[big_zop]

massively stiff swaybars going into the car...

Swaybars make no difference to drag racing unless they arent free in their movement.

As for the rear springs, they wont affect the amount of weight transfered to the rear wheels but they will affect the rate and thus the behavoiur of the rear, with a stiffer spring you will get a faster transfer rate.

While many would say that softer is better, this is not always the case and depends on so many factors that the only way to know whats right for your car is to test. Things that might go against a soft rear is camber gain but the amount of squat (not an issue with solid axle suspension) and the amount of movement leading to tramping if not controleed properly.

If you really want to have a proper go at drag racing, try both your race setup and some stock suspension (since you should have both and the ability to swap - though im not recommending on the same night) and remove the swaybars completely if its still going to be safe enough to drive there.

[Smokey228]

i understand that you spend less time on the track with a better launch and thus a lower mph. I actualy heard, that one particular vl turbo was having trouble breaking into the 10s, so they let the launch fuck out and spin, but then got on it and got the time they were after cause they were able to spend more time on the track accelerating..

Or something like that anyway!

I've actualy run 109mph every run, wether it be a 13.1 or a 12.5... Which doesnt make perfect sense to me :S lol

Im still blown away that a stock 1j will make 260rwkw. If all i need is 2j injectors, exhaust and cooler, and an ECU, i should be good for 250rwkw then. And im very much happy with that, not to say i wont be going single one day!

Cheers,
Jase

[Stomps]

hmm, interesting... i've always heard that softer is better, but like i said, im no drag racing enthusiast, so im not really too cluey on drag setup... just going on what i have been told..

i must say, i had better success with softer rear springs and shocks that squatted a lot more... the last time i went i had tein HR's in the back with 14kg rear spring rate, really wasnt helpful..

im gonna set my car up to be as stiff and flat as possible and just see how i go at the drags.. ill be happy with a 12 to be honest... as long as it slides well at wannaz (local track) ill be happy

Swaybars make no difference to drag racing unless they arent free in their movement.

As for the rear springs, they wont affect the amount of weight transfered to the rear wheels but they will affect the rate and thus the behavoiur of the rear, with a stiffer spring you will get a faster transfer rate.

While many would say that softer is better, this is not always the case and depends on so many factors that the only way to know whats right for your car is to test. Things that might go against a soft rear is camber gain but the amount of squat (not an issue with solid axle suspension) and the amount of movement leading to tramping if not controleed properly.

If you really want to have a proper go at drag racing, try both your race setup and some stock suspension (since you should have both and the ability to swap - though im not recommending on the same night) and remove the swaybars completely if its still going to be safe enough to drive there.

[big_zop]

Im still blown away that a stock 1j will make 260rwkw. If all i need is 2j injectors, exhaust and cooler, and an ECU, i should be good for 250rwkw then. And im very much happy with that, not to say i wont be going single one day!

Cheers,
Jase

Dont forget dumps if you havent already go them (tried searching but couldnt tell - plus i cant see pics at work) - should be the first thing to go on as they reduce the amount of heat that the turbos are exposed to and extend their life (yes this is here-say and i have yet to see any one measure temps to prove it) but you cant argue with the perfomance gain from fitting them either.

Its just a pain in the arse to do while the engine is still installed.

[Smokey228]

I dont have dumps, but im not going to bother, as in my application, it will mean a very custom setup, and will cost far to much, probably in the vacinity of 1k...

I'll be going single when these turbos die...

Cheers,
Jase

[Smokey228]

Made 240.3 rwkw at 16psi with PowerFC and is mapped to 18psi and kept making power on the dyno, but i dont have a read out!

Cheers,
Jase

[big_zop]

Glad it worked out for you! Thats a lot of power with the stock dumps. What was it before, 190 something?

When is it hititng the track next?