power loss ? igintion ?

[kaje36]

I dynoed my car a few months agow and got 213 rwhp and 226 ftlbs at 5.9 psi. the engine died ( prior fuel starvation )

I replaced the engine, removed the AC and clutch fan most everthing was the same. running more fuel, AVCR, and fixed large boost leakes. dynoed again with the new engine ( 185 compression ) and got very horrible nunbers... 188 rwhp and 220 ftlbs at a unstable 10psi ( dropped to about 6 psi at the end of the rpm range ) I was more worried about my lack of power then makeing the boost stable.

only thing that anyone could figure out is that it was ignition related. I had Jay hass, AceInHole and Boosteds14 working on my ignition and was still crappy. only thing anyone could think of was that my ECU was screwing with the timeing. I have tried clearing the ECU a few times with no improvment. I replaced my plugs a few times ( one set from AceInHoles car ) I also replaced my wires.. and the car felt a little better after that one.

I havent been able to get ahold of a good OBDII scanner yet. but if that is the issue how would I get the ECU back to base timeing. and if it isnt the issue then what else could it be ?

I am at a loss. only other issue I know of if I have a small vacume leak upseting my idle, and I am working to track that down, but I dont think that could cause this problem

I have a KA
45 trim T3
AVCR
SAFC II
370cc 50psi FPR
Wallbro 255
SMIC ( FMIC waiting welding )
HKS actuator
3000gt BOV ( wrx bov waiting piping )
s13 exhaust cam in intake
z32 maf
NGK iridium / coper plugs - .035 / .030 gap


thanks for any help
Mark

[mrmephistopheles]

I am posting this in advanced couse no one can seem to figure out the problem.
Mark

Nice 'copy and paste from FA' post. :jerkit:

have you checked your TPS?

[kaje36]

ya like that ?? good old ADD at its best.. and still no responces on FA...

TPS seems to be working fine.. its been unpluged and repluged a few times trying to play with the timeing. and the Safc seems to read the signal fine

[mrmephistopheles]

You can unplug and replug it all you like.. If it's set wrong it won't work right.

[kaje36]

tps is fine, use the safc like I said, and 100% is full throttle and it reads fine all the way threw. TPS also hasnt been changed between motors, besides the block and head the 2 motors are the same.

[kaje36]

well I played with the OBD II scanner, cleared up all teh random codes ( acualy fixed them too ) and was able to acualy check the timeing.. after a few runs I got anyware from 19 -22 degrees advanced at 6k rpm. I dont seem to be seeing much knock from the knock sensor eather ( SAFC II ) anyware from 50 - 100 ( raw data )depending on how long the engine has been running.

I know this has got to be something very stupid..... :bash:

I have been driving the car all week, and still no codes ( it acualy stayed fixed )

everyone keeps telling me I should just go standalone.. but I would like to know why before I carry problems over to that....

[Id-]

dude, think about it

you make peak torque like you used to; but your complaining that boost falls off when kicking up the rpms

i bet you money if you stopped the boost from falling off and kept it at the peak you hit earlier in the rpm band that your power would magically reappear

SR20s on stock T25s should make about even torque and horsepower... sometimes slightly more torque; but not 40ft-lbs more; its your boost falling off thats causing the problem; boost peaks then torque peaks; rpms build up, but torque dies off from boost dropoff; therefore horsepower at peak drops a lot

this is a common problem with SupraTTs; they peak at 18-19psi but dropoff to around 15-16...
they only make ~375-380rwhp this way; when doing a certain wastegate mod (spring mod) they can hold 19-20psi to redline and then they make 400-420rwhp :) peak torque stays the same tho

[kaje36]

yes I do relize that but my boost the 2nd time was 10 psi and I made less tq then I did at 6 psi ( 220 comparies to 226 ) also base timeing was advanced to 23 degress for me to get thows numbers at 10 psi.

if anyone wants to look at the sheets... there is definitly something going wrong http://www.bristoldyno.com/vehicles/Nissan/240Sx/Brook_Mark/

I think when i did a 7 psi run it was like 140rwhp or something silly like that, and I think for the most part that was stable..

[Id-]

i'm still convinced its boost drop off... in your original thread you made no mention of a 2nd run equaling the 188rwhp

pull your boost controller and run directly off the wastegate

its not hard to do so might as well try it

[kaje36]

yes some of it is boost drop off..

but timeing is suposed to be at 28 degrees advanced.. and its not.. so clearly its timeing. why or how to fix it I dont know.

also I did a stable 7 psi run and it was 152ftlbs and 136rwhp I found the exact run.. run 17 for thows that wanna look at it..

I do apoligise if I am being a dick, but I would realy like my power back.. or to know how to fix it..