I have dual stage boost controller and I know I should dyno my car (haven't had time/money) but after tuning (12 AFR for 6 psi and 11.7 AFR for 10 psi, I feel not much difference between them on my butt dyno..

Is there something wrong with the motor? I don't think there is any leak because I see the boost gage spooling up quick and solid.

 

Probably a tuning issue. The AFR's are one thing but your timing is also important.

I have noticed in my car, if I floor it I make 11.5:1 AFR at full boost, but if I go partial throttle it will be more like 13:1 at full boost. The car is much quicker with the leaner AFR.

 

What is your timing like?

You should feel a night and day difference from 6 psi to 10 psi.

 

on low cam, timing on 6 psi is 21 deg, at 10 psi is 17 deg
on high cam, timing on 6 psi is 27 deg, at 10 psi is 23 deg

I'm running step retard

 

interest in it too...

 

What size turbo do you have, maybe your maxing it out..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elpiar &raquo;</TD></TR><TR><TD CLASS="quote">on low cam, timing on 6 psi is 21 deg, at 10 psi is 17 deg
on high cam, timing on 6 psi is 27 deg, at 10 psi is 23 deg

I'm running step retard </TD></TR></TABLE>

shouldn't this be switched around so your running less degrees under high boost? or am i totaly wronge?

 

what turbo?

 

he is right... ha has less advance on higher boost... just re-read ... but he has more advance on highcam then on lowcam but this is just normal...

i don't think he maxed out his turbo... not at 10psi ... even a T25 should be able to make power at 10psi on our small displacement honda engines.

but tell us the turbo you have... maybe it helps.

whats about boost leaks? i had a car that didn't want to be faster even if i rise boost and it had a boost leak... just a small one but it was one there that causes the problem.

best regards
Malte.

 

I've got a T3 .48/.42 on B18C1

Also, for some reason, I feel more torque between 3k to 4.5k, and then not that aggressive until it reaches 6.5k. I know for sure my AFR is tuned flat to 12.5 throughout rpm range. (or 11.8 for 10 psi)

I have stock motor btw, haven't mess around with it since I bought it. It's a 2000 GSR with 95k miles.

 

If I can boost fast and consistent (on my boost gage) then there shouldn't be any boost leak right? I mean, even if there is one, the pressure at intake manifold still exist as it is, right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Snail Tuning &raquo;</TD></TR><TR><TD CLASS="quote">shouldn't this be switched around so your running less degrees under high boost? or am i totaly wronge?</TD></TR></TABLE>

Those are values from uberdata, which refers to the amount of advance before TDC

 

try adjusting vtec, when is your crossover set at now? you may need to raise it up to keep the torq climbing

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Snail Tuning &raquo;</TD></TR><TR><TD CLASS="quote">try adjusting vtec, when is your crossover set at now? you may need to raise it up to keep the torq climbing</TD></TR></TABLE>

Right now it is at 4.3k, today I set the vtec off to tune low cam basemap again since I cleaned up my filthy air filter.

I haven't tried that yet.

 

More persepective?

 

a t3.42/.48 on a gsr?
WAY too smal.
Buy a REAL turbo.

 

that turbo is way to small for that motor.

 

put vtec at 5200k

 

If I use t3/t04e when should I expect full boost?

my turbo is really fun to drive now full 6 psi boost at 2500 rpm

 

fullb oost by 2500 and fall on it face at 6000 and oyu rev to 8000, no wonder it felt the same

 

The big question is how do I know it's the turbo going out of breath or is it something wrong with my motor?

 

You know because that turbo is too small for that motor, guaranteed. My non-vtec sohc has a bigger turbo that that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nonvtecD &raquo;</TD></TR><TR><TD CLASS="quote">You know because that turbo is too small for that motor, guaranteed. My non-vtec sohc has a bigger turbo that that.</TD></TR></TABLE>

Maybe if someone can help me read compressor maps and how to determine volumetric efficiency? I've been curious about this topic.

 

the timing seems a little bit too advanced. when i street tune turbo cars on about 10psi, i set the overall timing to be around 19*. then i take the car on the dyno and play with the ignition tables.

get ur cheap *** on a dyno!

 

the t3 probably cant keep up in the higher RPMs. A t3/t4 will have a higher boost threshold but you will be rewarded with some real power that holds to redline.