ominous 87 's dyno

 

red z28 dyno

 

my dyno graph

 

i noticed that on these graphs the most torque is at
the beginning of the pull and falls from there . is the torque
converter influencing these numbers ? i dynoed a carb'd
355 with a loose converter and had the same thing
450 rwtq at the hit and then falling , rwhp was 320
i am not criticizing - flaming - doubting etc as you both
have faster timeslips than i do right now i am just looking
at the shape of my graph and the shape of another
graph for a 90 l98 i just dyno'd ..

any other dyno graphs out there were the torque climbs
after the pull starts ?

mike

 

i was just thinking if you were to have the same
shape of the torque curve at 2000 rpm it would be over
500 rwtq .. can this be right? engine dyno pulls
i have seen generally show small blocks torque peak
at 3500 to 5000 depending on how big of a cam
is stuck in it

 

I know my torque convertor Locks up at about 4,000 rpm in 3rd gear so if it is making a difference its not much at least not on my car from what i can see.

 

A dyno is by no means a perfect science.

Different dynos and different software display results different.

Locking up a converter will bump up rwhp numbers 10-15 hp over if the converter was unlocked on a dyno.

My motor and Reds motor are TQ Pigs, the only way to build something that makes more TQ is to add more cubes. Just think of it like that.

Dynos are good for tuning gas and spark, and thats it. They are only comparable when used on the same day in the same conditions.

The track is the only place to really get a good feel about how tight your combo is.

MPH is everything, then you need to consider the weight of the car to get an idea of what your motor is really putting out.

Otherwise everything else is just playin with paper.

FYI, I do not lock my converter at the track or at the dyno, the 2800rpm Vigi is tight enough for my taste, locking it up under load means you are risking the clutch, so I stay away from that risk.

 

With my 350 my car would slow down if I didnt lock the torque converter. I lock it up still with my new motor. My friends 85 Vette has locked his up for 10 years with no problems, and also his car went slower with it unlocked. But that is my experience. Not saying what anyone else should do, thats up to you Hey Ominous did you get that file I sent you ?

 

Yeah thats pretty much what everyone agrees upon with locking the verter, you will pick up some speed.

I have heard alot of stories from the turbo buick guys that have blown their vigis by locking em up, hence why PI created the 5-disk unit.

I am tempted to lock it up to try and pick up a couple MPH the next time I hit the track, but I just dont think that at the end of the day I will risk it.

Oh well.............

 

The printout and graph I got from the shop showed my torque peak to be 344lb/ft at 4500 and looked like your graph. When I ran the disk they burned me in the dynojet viewer, it added the converter's torque multiplication into the run and showed over 420 lb/ft at the 2800 rpm starting point,, like the other graphs you posted.

 

bad ss what brand dyno were you on that
gave a readout on engine and chassis power
mustang or dynojet
what's your combo and have you raced it ?

mike

 

It was a DynoJet. I’ve only been on the dyno twice, but it was at two different DynoJet shops. Power was near identical,,, within 1% of each other. Both the readings I saw from the shops were rear wheel, but the shop’s software factored out the converter flash somehow (more advanced than the on-line viewer???). The DynoJet viewer software that I downloaded from their site to run the disks doesn’t - at least I couldn’t figure out how.

Combo - 86 IROC, 9.8:1 compression 355, box stock stock G1 TFS heads, 218/228-110 cam, StealthRam, MAF system, DIY ram-air, K&N filters, 1 5/8” Headmans, custom dual 2.25” to 3” Y-pipe, 3” Race Series DynoMax, TH350 trans, TCI 3,000 rpm stall, 3.23 gears, stock suspension (at that time), 26 x 11.5 ET Streets. Car weighs a little over 3500lbs with me in it.

Best ET was 12.36? at 109.9? mph in cool weather with a mid 1.8 60ft. That was with a stock chip,,, so I was giving away a little et and mph with the tune. The car needed more gear with the StealthRam also.