Strange Hesitation Sensation In My Car

[Mr_Chunkz]

well thats why i explained each pic
if i take a pic of the whole page it blurs it pretty bad

And vik, i know that i should be making much much more than 216WHP, but remember, my boost started to slip right at peak power figures. Once i hit 6psi and went past 5k, it dropped slowly all the way to about 4 and a half....

The problem has since been fixed but ive not had a chance to run another pull after the installation of the new belt.

[Mr_Chunkz]

edited dyno sheets post hopefully making it easier to understand and also explaining each pic.

Oh and before anyone asks

I Have replaced my SC belt already with the correct size, however, i havent had a chance to make a few dyno runs on it to find out WHP after the belt change...

[Eye8Pussies]

hmmm...looks very interesting....I wonder how the torque peaks so early....maybe its the ignition booster...never seen a 1mz with a graph quite like that

as for the power, I'd like to see another run now that the boost problem has been fixed. But from the looks of the graph, I wouldn't expect much more. It isn't taking a dive at that point as much as just becoming stagnant. I'd say maybe 10whp at that point there. If it had peaked at 4K, I'd say you have a lot more to go, but at that point...it's not going too far too fast anyway.

How are the SAE corrections?



And let us know when you have the time to hit up the dyno again

[Mr_Chunkz]

it seems to me there is something strange going on at 2500 rpm cause hp has a slight increase as well as torque. Im not sure why it looks that way i can tell you that having torque that low feels great. Makes my car feel very "muscley"

[Eye8Pussies]

yeah, I would think so for sure...though, by the same token, it's not too too crazy what you're showing there...you're just getting the torque about 500rpms earlier than most other ppl...but the torque drops off so fast though...it must feel like the car runs out of balls as the revs climb and you lose 50ft/lbs of torque

what do you use for tuning? safc?

[Mr_Chunkz]

yeah, I would think so for sure...though, by the same token, it's not too too crazy what you're showing there...you're just getting the torque about 500rpms earlier than most other ppl...but the torque drops off so fast though...it must feel like the car runs out of balls as the revs climb and you lose 50ft/lbs of torque

what do you use for tuning? safc?

well actually with my belt problem solved the car feels very strong on the top end as well. On the freeway it puts a nice big smile on my face, but i do have to admit on the street it feels much much more potent than freeway running...

Im currently tuned on an AFC Neo

[gnegroni]

Found cause of hesitation
my car was running very very lean
17.1AFR in fact. The guys at the dyno shop told me that it wasnt safe for me to run my car hard ( oops ) but fixed it all up for me

New dyno showed 250.1 Ft/Lb TQ @ Wheels @ 3300rpm but I couldnt get an accurate peak power reading because my 5.5 belt slipped on my 6psi pulley. The power stops climbing @ 216WHP but im sure the car has much much more to give.

In other words, the MSD DIS4 ignition was causing the lean ignition? Isn't that good? In other words, the ignition is burning way cleaner than the stock one, and once tuned, you'd make more power.

hmmm...looks very interesting....I wonder how the torque peaks so early....maybe its the ignition booster...never seen a 1mz with a graph quite like that

as for the power, I'd like to see another run now that the boost problem has been fixed. But from the looks of the graph, I wouldn't expect much more. It isn't taking a dive at that point as much as just becoming stagnant. I'd say maybe 10whp at that point there. If it had peaked at 4K, I'd say you have a lot more to go, but at that point...it's not going too far too fast anyway.

How are the SAE corrections?



And let us know when you have the time to hit up the dyno again

If your engines typically peak torque at say 4000rpm, how does his graph numbers at 4000rpm compare to "normal" engine config with a similar setup (S/C) and around the same PSI.

well actually with my belt problem solved the car feels very strong on the top end as well. On the freeway it puts a nice big smile on my face, but i do have to admit on the street it feels much much more potent than freeway running...

Im currently tuned on an AFC Neo

Did the fix actually move the torque curve back to normal? Any change in regards to that, at all?

[Mr_Chunkz]

In other words, the MSD DIS4 ignition was causing the lean ignition? Isn't that good? In other words, the ignition is burning way cleaner than the stock one, and once tuned, you'd make more power.

Did the fix actually move the torque curve back to normal? Any change in regards to that, at all?

The MSD Advances ignition timing so far as I know, and is supposed to add power. The lean condition on my car could have been caused by ignition, up sizing exhast piping or increasing boost but most likely a combination of both. With an AFR that lean, however, my car was severely retarding timing, trying to save my motor from blowing. Im sure that because now I am properly tuned I am making more power due to the MSD box.

The fix doesnt feel like it moved the torque curve at all, and I'm not sure what one would consider "normal" torque curve. My torque spikes where it does because, as I was informed, that was when my SC hit full boost. The only thing that changed with a new belt was the top end power feels alot better, much much more satisfying surge on the top end.

[gnegroni]

The MSD Advances ignition timing so far as I know, and is supposed to add power. The lean condition on my car could have been caused by ignition, up sizing exhast piping or increasing boost but most likely a combination of both. With an AFR that lean, however, my car was severely retarding timing, trying to save my motor from blowing. Im sure that because now I am properly tuned I am making more power due to the MSD box.

The fix doesnt feel like it moved the torque curve at all, and I'm not sure what one would consider "normal" torque curve. My torque spikes where it does because, as I was informed, that was when my SC hit full boost. The only thing that changed with a new belt was the top end power feels alot better, much much more satisfying surge on the top end.

Nice about the MSD box. Wonder if there were such a box for the VVti engines how would it fare?

Chunkz, if you don't mind could you please set me up a PM with your specs? I know there is a post with everybody's specs, but I'm a bit lazy and in a hurry for now.