Pulsar Dyno results

[nismoplsr]

went to the dyno today



194.4 hp and 195.7 ft/lb tq

89.7 deg f 83% humidity

air fuel about 11.5 all the way

[Trigger]

nice solid run...whats the specs on the engine again?

Tim

[nismoplsr]

CA18DET

rebuilt headSpearco 26x6x3 intercooler2.5 plumbing and exhaustHaltech E6KUnorthodox underdrive crank pulley

14 psi on stock t25

[GoofyATX240]

Wow nice work man.

[JICdrifter]

which model car is the pulley for? do u have a part number by chance?

[nismoplsr]

sorry, it was the only one made.

[Nismo_Freak]

You'd prolly get into the 200's with a S-AFC

[N.O. Accorderz]

^^^ i though the haltech does everything?

[boost_boy]

Car sounds like it's tuned a little on the rich side. What's your timing like? I am interested to know and you can even discuss this in private with me. The reason I'm asking is you should be producing a bit more power even with a crappy deuce and a quarter hairdryer. And yeah Nismo_Freak, no need for a safc with the haltech, unless you meant he can get that with just a safc and a stock nissan engine management system.

Dee

[paul_s13]

Car sounds like it's tuned a little on the rich side. What's your timing like? I am interested to know and you can even discuss this in private with me. The reason I'm asking is you should be producing a bit more power even with a crappy deuce and a quarter hairdryer. And yeah Nismo_Freak, no need for a safc with the haltech, unless you meant he can get that with just a safc and a stock nissan engine management system.

Dee

I agree 11.5 is a bit on the rich side, you should get a fair bit more power with the mix at 12.5 but not a huge amount more, but it would be better to ditch the T25 and fit a T28 and run that at about 14-15 psi, this should get you about 280-ish @ the fly anymore boost and your injectors will really struggle.

[WeldingHank]

you shoulda showed up to the 240sx dyno that we had to day before at bristol dyno!

[nismoplsr]

yea i know i loose a lil more power with it being so rich

it even dips as low as 10.8 at max tq

as for the timing the haltech says 36 deg in some spots. obveiously it is wrong.

we had a problem when tuning it .

couldnt get the base timing correct, at first i thought it was the marks on the pulley. but now i think this is because we were using the loop off the ignitor not the spark plug wire method. so estimated the timing is 10-15 deg off

this friday i am installing a GT28RSLucas 550cc injectorsNISMO fuel pressure regulator300zx tt fuel pump

and getting it retuned on the dyno.

i am hoping to break 300whp at 18-19 psi

[boost_boy]

Sounds like someone is upgrading finally;) ! For the amount of money you spent on your car and using the haltech, I know you can come up with better #s than that. Quick question Stevie, what is your max timing on you haltech? I mean, what is the highest fuel mark (# wise on your bar graphs) that you see? The problem with this is, too much timing and too much fuel will get you less than perfect results. That T2-poop should've at least got you around 230ish-240ish whp and that's pushing it. Whomever's tuning your car let them know that this engine is not a timing lover and anything over 27 degrees of total timing is dangerous; especially on street gas.

Dee

[paul_s13]

That T2-poop should've at least got you around 230ish-240ish whp and that's pushing it.

I've never seen a T25 put out more than 240bhp @ the fly but there does seem to be quite a difference in the SAE and DIN power measurements.

[boost_boy]

Like I stated before, 230ish-240ish is not impossible, but definitely pushing it. Different dynos seem to give different figures, but toying witht the T25 and high boost is a recipe for blown motor.

Dee

[paul_s13]

Like I stated before, 230ish-240ish is not impossible, but definitely pushing it. Different dynos seem to give different figures, but toying witht the T25 and high boost is a recipe for blown motor.

Dee

Yeah but evey power figure stated here is stated as whp not at the flywheel, there is not a hope in hell of getting 240@ the wheels with a T25.

[boost_boy]

Quote »Yeah but evey power figure stated here is stated as whp not at the flywheel, there is not a hope in hell of getting 240@ the wheels with a T25.[/quote] Hmm Paul, it's hard for me to totally agree with this since there wasn't a mentioning of different injectors, engine management, intercooler, piping etc, etc. I never dyno tested any of my vehicles with the T25, but I have run the car with an upgraded T25 and by all means I figured the car was anywhere between 230ish-250ish whp. Once again, I personally would not go hunting for that type of power out of a stock CA18DET T25 or an SR's unit for that matter, even though the SR has slightly larger A/R in the rear at .64 as opposed to the .48 of the CA's. Measuring HP losses are different for FWD as opposed to RWD. There's just not as much parasitic losses from FWD which makes that T25 just that more potent in FWD form.

Dee

[paul_s13]

The issue i'm getting at is where the power is quoted, im my experience (and I've seen probably over a 100 sx dyno runs at SXOC dyno days) s13/s14's tend to loose between 30-40bhp through the transmission so when i see figures of 240bhp @ the wheels i tend to assume 270-80bhp @ the fly. Those figures are possible with standard injectors and MAF (i got 301bhp with a transmission loss of 29bhp so I would quote obviously 272whp with standard injectors and raised fuel pressure and I mapped the standard management)

I don't reccomend that anyone does this because the injectors were maxing out at 270-280bhp but I wanted to win the dyno day.

I've just heard a few things about the % difference in bhp measurement between the two different standards that we use, from one source I calculated that my old car had near 343bhp whp but I know it had nowhere near that.

I also doubt that the transmission losses would be that different between modern FWD and RWD gearboxes.

Just my 2p worth

[boost_boy]

Since I have no basis of proving this and could care less about proving it, I'll stand down on this topic. Try this at home folks and kiss your pistons goodbye.Quote »I also doubt that the transmission losses would be that different between modern FWD and RWD gearboxes.[/quote] But on this subject, I'll definitely disagree. RWD vehicles use driveshafts, seperate differentials and axles to transfer power from the engine. In FWD configuration, everything is in-house. This argument has been brought up numerous times in the U.S. about FWD and RWD power losses. IIRC, RWD loses 20-25% hp and FWD has 15% drivetrain loss. As with the topic of the T25, I stand down. My cars are very modified especially the gearboxes, so it doesn't matter to me either way; the power will eventually make it to the ground.

Dee

[pulsar gtr]

hUM, thats an interesting topic.

Actually, I did a dyno on my pulsar about 3 years ago when it had stock every thing including a stock top mount intercooler, I got 202whp(aprox 242flywheel hp) at 16psi on that T25 at 6500 rpm.I had jwt ecu and z32maf, z32 fuel pump, so to achieve 230whp on stock T25 is kind of real hard, but every one knows that jwt runs rich and I was running rich which could of resulted in losing few hp, so may be that would of put me in 210whp. But I gotta agree with paul, I don't think a T25 can reach 230whp, not sure about the SR t25 as it has a different A/R.Boost boy gotta point regarding FWD Vs. RWD, RWD loses more power than the fwd as it got two extra moving parts, drive shaft and the rear diff.But very interesting arguement though. Keep it going

PULSAR GTR

[nismoplsr]

max injector pulse was 9.465ms

and max timing was 50deg

[paul_s13]

Boost boy gotta point regarding FWD Vs. RWD, RWD loses more power than the fwd as it got two extra moving parts, drive shaft and the rear diff.But very interesting arguement though. Keep it going

PULSAR GTR

Well as I said before, nearly all the s13/s14's I have seen loose between 10-15% on their dyno runs, just going on what I've seen and my recent dyno operating experience.

[boost_boy]

Quote »and max timing was 50deg [/quote] Jesus christ:eek: . There isn't that much difference between most standalone timing references, but if your max timing is 50 degrees, man you are waaaaaaaaaaaayyyyyyy over the limit. The SR uses about 30-32 degress of timing and that's somewhat extreme to say the least. You are actually losing power! If I wasn't so far gone in modding my car, I would take a standard T25 and rape it on the dyno with my standalone. I'm pretty sure I can do better than 200whp when tuned correctly. Nismo, that timing is wicked man! Maybe you max timing is 50 degrees, but how much degree of retard you use? Because if you're running that much timing with no retard, pop goes the weasel when you try to run sustained bursts.

I guess the argument continues about UK, US and Aussie DYNO figures and performance. Any more input? We have a lot of members with CA18s and T25s at work; has anyone gone to the dyno with this combo as of lately?

Dee

[LoserbabyS13]

On RWD's if you are dynoing in 4th gear you are actually going to have very little transmission losses because 4th gear is hooked up straight to the engine on most (including nissan) RWD transmissions. Also think about this one for a minute if you engine is making 300 FLY HP and you assume a 20% trans dirve loss you get 240 at the wheels or 60 hp lost. Where did that 60 hp go? It has to go somewhere because of the 1st law of thermodynamics that states matter and energy cannot be created or destroyed. Hp is a form of energy and that 60 hp is the equivalent of about 45,000 watts. This power has to go somewhere and I highly doubt that the transmission could disapte this power as heat. Because if this 60hp is heat it would undoubtly boil the the oil in the transmission case and cause all kinds of nasty transmission problems. I am going to suggest that chassis dynos are where the real problem lies is messuring accurately engine power output. Chassis dynos should primarily be used as tuning aides rather than the quantitative messurement of engine output. Here is some of my source information and a few good articles to read about chassis dynos.

http://www.sportcompactcarweb....bble/

http://www.sdsefi.com/techdyno.htm

http://www.vishnutuning.com/dynos_dont_lie.htm

[pulsar gtr]

LoserbabyS13, I am glade you are on this forum, I guess we have some thermodynamics/physics gurro on here, very interesting theory, I would say, this 60hp lose is divided to the flywheel weight, drive shaft, diff, axes, + plus the weight of the car against the Rear wheels, plus friction. some of it get transfered into heat at different locations, and don't forget your clutch, it transfer some this hp into heat as well, I hope that makes some sense, because I start confusing myself.

PULSAR GTR

[pulsar gtr]

Loserbabys13, Actually these are pretty interesting links, good jobvery nice articles for sure.

PULSAR GTR

Rafi

[LoserbabyS13]

Very true pulsar but most people dont take these things into account also you would have to take into acount of the entire rotating assambly after the flywheel including the brake rotors/drums and the drag of the brake pads. I gues my point is that the transmission itself has alot less loss than people realize and the real problem is that the chassis dyno cannnot take into account all rotating mass and drag for every car therefore it cannot be 100% accurate for massuring true HP.

[pulsar gtr]

True to that, I gotta agree with that, I guess thats why they use a generic 20% lose on dyno machines, not all cars have the same setup in hardware, and using a 20% loss means you can lose up to 20%.

PULSAR GTR

[LoserbabyS13]

true but if you read the articles you will see that most 4th gear pulls on a RWD is going to have very litte loss because the input and output shafts are locked and therefore their is no transmission loss at all just the drag and rotating losses which are very little as well. I think they say the 20% partly as a marketing ploy and to bridge the gap from what an engine dyno says VS what a chassis dyno says and they decided that it was best to desribe this as transmission loss.

[pulsar gtr]

Sounds good, and I did read that article and found it pretty educative actually.

PULSAR GTR