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-   -   stock port rew/ efr 8374 low on power? (https://www.rx7club.com/single-turbo-rx-7s-23/stock-port-rew-efr-8374-low-power-1157178/)

AlexG13B 05-26-22 01:01 PM

stock port rew/ efr 8374 low on power?
 
running an iwg efr 8374 on stock port rew. hit the dyno and it seems like its not making the power it should? alittle backround runnning brand new haltech coils, elite 1500 on pump 93 and aem meth controlled by haltech. these numbers are from a dyno jet
did a baseline run with tuner. at 14 psi it made about 330 with safe timing numbers. after about hr or so we start adding the meth.
first pull it went down to 300hp on same boost with AFRS in high 10s

after another hr of tickering the afr, adding 3 MORE lbs of boost (so around 18 now) and adding more timing we ended up at 343hp and 315 tq. tuner said something isnt right and we should stop. he said that should be 400hp all day
i have double checked the base timing on leading and trailing. from idle to 8k rpms and was pretty much dead on. EMAP was LOWER then IMP till around 6000 rpms i believe then it was closer to 1:1
egts looked good. afrs high 10s but for some reason not making the power "it should"

tuner is sorta stumped and i am as well.
motor made about 100 psi on all faces HOT so compression is good, runnig a brand new greddy VMIC, 3" downpipe to resonator and apexi n1 duals.
i have smoked the intake before didnt see any leaks but havent tried pressurizing it. fuel pressure was good, kock level good. knock actually dropped with ai and the uim would get really cool

temps were high about 90* ambient with 50% humidity. and we were having issues with the dynojet not reading to 7,500 or higher rpms.
so i guess the actual number isnt much of the concern as is the difference between power at 14 pump vs 18 psi with ai and more timing?

any thoughts or info im missing?
https://cimg4.ibsrv.net/gimg/www.rx7...43365247e1.jpg
https://cimg5.ibsrv.net/gimg/www.rx7...8179a95c85.jpg

AlexG13B 05-28-22 08:06 AM

from last pull
 
https://cimg1.ibsrv.net/gimg/www.rx7...fec41c2949.jpg
https://cimg9.ibsrv.net/gimg/www.rx7...42efda5d6b.jpg

TeamRX8 05-28-22 09:56 AM

What’s on the inlet side of the turbo compressor?

.

j9fd3s 05-28-22 10:37 AM

how about a boost leak? 183k turbo RPM at 2.2pr is way off the chart...

https://cdn.borgwarner.com/docs/defa...sn=865ab03c_17

TeamRX8 05-28-22 11:25 AM

Good point assuming it’s accurate, I can’t read those photos very well on my phone. Even though it was smoked prior, that doesn’t mean something didn’t let loose after.

Flow not making it to the engine is the likely culprit, but struggling to believe it actually went to 183k when the graph ends at 128k, since that theoretically would be the stall speed. It would attest to the strength of the components to go 50% beyond that and not come apart. It went beyond the 128k limit way early in the run is also adding to my doubt on the rotating speed accuracy.

j9fd3s 05-28-22 11:47 AM


Originally Posted by TeamRX8 (Post 12519989)
Good point assuming it’s accurate, I can’t read those photos very well on my phone. Even though it was smoked prior, that doesn’t mean something didn’t let loose after.

Flow not making it to the engine is the likely culprit, but struggling to believe it actually went to 183k when the graph ends at 128k, since that theoretically would be the stall speed. It would attest to the strength of the components to go 50% beyond that and not come apart. It went beyond the 128k limit way early in the run is also adding to my doubt on the rotating speed accuracy.

i blew up the picture, and it was surprisingly legible. but yeah, it is so far off its kind of suspect.

TeamRX8 05-28-22 12:32 PM

I would suppose that a low cost, hand-held non-contact tachometer could read the rpm speed of the compressor inducer with the inlet piping removed for verification.

It would still make sense to smoke the intake system again regardless.

otherwise there are many stock port EFR8374 example threads in this forum section making 400-450 whp as proposed.
.

AlexG13B 05-28-22 02:28 PM

ya i will try and do a boost leak. its the only thing i can think of that may be causing my problem
https://cimg7.ibsrv.net/gimg/www.rx7...b2d45d3a49.jpg
https://cimg8.ibsrv.net/gimg/www.rx7...ad9281a11a.jpg

AlexG13B 05-28-22 02:29 PM

and yes i do suppose my calibration can be off on sensor. i need to find the right one!

TeamRX8 05-28-22 03:22 PM

probably not the pre-turbo intake, thanks for clarifying
.

AlexG13B 05-28-22 04:33 PM


Originally Posted by TeamRX8 (Post 12520018)
probably not the pre-turbo intake, thanks for clarifying
.

if I remeber it's a 4" aem dry filter and 4" silicone coupler

TeamRX8 05-28-22 07:18 PM

I saw it in the other post you made in the unrelated 3rd Gen forum thread.

https://www.rx7club.com/time-slips-d.../#post12520014

It’s very unlikely to be that, just that it wasn’t known previously.

Nice looking engine bay, btw. :patriot:
.

BLUE TII 05-28-22 08:38 PM

Where was the boost reference line taken off from?

BLUE TII 05-28-22 09:20 PM

^^
was thinking if boost reference was off the compressor cover, so not showing the usual pressure drop of IC- since the other parameters besides boost/power realtionship look good.

But now thinking on the other side of the pressure ratio (high turbo inlet vacuum) like teamrx8.

When I was selecting an airfilter for my FC I spoke to a tech and he said dryflow is just for hotwire MAF cars (oil contamination issue) and their traditional oiled filters flow better.

Try taking air filter off.
when I took off my 6" base, 12" long oiled K&N boost dropped from 12psi to 10 psi and power remained the same. Thats how much a superior flowing filter affected pressure ratio on my FC.

Howard Coleman 05-29-22 07:15 AM

an interesting and challenging situation. you are down, easily 100 hp. a boost leak that large would clearly be heard so take that off the list. airfilter also. i would go back to your dyno runs and look at them with zero smoothing. misfires, would show and could be a possibility.

Slides 05-29-22 07:52 AM

Not the old rag in intercooler? Or collapsed cat or exhaust flex? Any soft hosing between filter and turbo?

Warm up secondary throttles functional or removed?

AlexG13B 05-29-22 02:50 PM

thanx for the into guys I really appreciate the help!
so the reference is off the uim in stock map sensor location. I surely hope there isn't a rag in the intercooler pipes haha. warn up plates and been removed in the uim.
I was really hoping it to be something as simple as a boost leak, ill see if he can open the file and remove the smoothing

I did notice charging voltage being alil low in that area. but not sure if that would be the culprit

AlexG13B 05-29-22 03:08 PM

I do have a 4" silicon tube between air filter and turbo!

WANKfactor 05-29-22 04:56 PM

You haven't left a rag inside the I/C end tank or anything?

AlexG13B 05-29-22 05:08 PM

I'll double check. I don't think I did but I guess anything is possible!

BLUE TII 05-29-22 05:14 PM

Really really nice set-up by the way.

AlexG13B 05-29-22 05:35 PM


Originally Posted by BLUE TII (Post 12520108)
Really really nice set-up by the way.

if ur talking to me well thank very much. means alot to me. i tried to spend time on little details like heat management and foaming every hole greddy vmic setup.
there is a link to I think the intake hose I used for turbo inlet
https://www.siliconeintakes.com/turb...-45-p-433.html

WANKfactor 05-29-22 05:45 PM

Yeah it looks spot on. Should rip

BLUE TII 05-30-22 01:57 AM

Just had a thought-
leak through the compressor bypass valve would be really hard to spot, but very easy to check for.

AlexG13B 05-30-22 07:11 AM


Originally Posted by BLUE TII (Post 12520140)
Just had a thought-
leak through the compressor bypass valve would be really hard to spot, but very easy to check for.

how can I check that? and that would be an internal leak in compressor housing right?


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