separating fiction from reality... a couple of days on the DYNO
12-13-10, 12:49 AM
#304
dorito powered
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Join Date: Mar 2008
Location: Lincoln, NE
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edit: this is an assumption, I may be wrong, but I doubt this is something howard overlooked.
12-13-10, 02:04 PM
#305
tard of teh century
https://www.rx7club.com/showthread.p...7&highlight=fd
That's the setup he is running for a transmission, clutch and so on.
That's the setup he is running for a transmission, clutch and so on.
12-13-10, 07:27 PM
#306
Sorry if i am cluttering this tread but i was looking at my compressor housing and i see that the port is between the larger and smaller blades. In other words i don't see why the ported shorud would make less power, If anything it seems like the ported shroud will allow more air flow to the compressor wheel. here are a few pics.
12-14-10, 10:32 AM
#307
the ported shroud works by bleeding air from the high pressure area back to the inlet to reduce surge and consequently expand the map to the left. So I suppose it is basically a factory designed leak which could reduce max power potential in favor of lower surge line.
12-14-10, 11:31 AM
#308
Racing Rotary Since 1983
Thread Starter
iTrader: (6)
just a quick update:
i am actually off the net as my Hughesnet dish got KO'd due to a blizzard last weekend. our usual plow guy didn't show and, being in the sticks, today was the first day i have been able to get my DD (Maz 6) out of the drive. so here i am back to semi-civilization at Panera's.
meanwhile we are moving ahead. Beyond Redline pulled my motor, i picked it up last week and disassembled it. i found nothing wrong. i will be switching back to my NRS ceramic seals as i didn't like the chatter marks and circumferential scratches on my absolutely like new housings. they had run 450 miles and about 30 dyno pulls since 2010 re-assembly.
when i pulled the ceramics after a year of usage it was impossible to detect the motor had been run. without any question my housings would have been junk if i had continued to run the motor in it's 2010 config.
FYI, i run Mobil One, with one oz premix on the dyno and i add 4 ounces of ZDDP.... so i do take care of biz lubewise and it has worked for 6 years.
the housings are going to Cam at Pettit and will get a diamond hone process so we won't be looking at ANY marking. Cam can turn them around in one day.
i have spent alot of time looking at the logs and we have eliminated any flow oriented viariable.
oh, and the clutch isn't slipping. BTW, it looks really nice.
'hopeful of a thawed Hughesnet dish...
howard
i am actually off the net as my Hughesnet dish got KO'd due to a blizzard last weekend. our usual plow guy didn't show and, being in the sticks, today was the first day i have been able to get my DD (Maz 6) out of the drive. so here i am back to semi-civilization at Panera's.
meanwhile we are moving ahead. Beyond Redline pulled my motor, i picked it up last week and disassembled it. i found nothing wrong. i will be switching back to my NRS ceramic seals as i didn't like the chatter marks and circumferential scratches on my absolutely like new housings. they had run 450 miles and about 30 dyno pulls since 2010 re-assembly.
when i pulled the ceramics after a year of usage it was impossible to detect the motor had been run. without any question my housings would have been junk if i had continued to run the motor in it's 2010 config.
FYI, i run Mobil One, with one oz premix on the dyno and i add 4 ounces of ZDDP.... so i do take care of biz lubewise and it has worked for 6 years.
the housings are going to Cam at Pettit and will get a diamond hone process so we won't be looking at ANY marking. Cam can turn them around in one day.
i have spent alot of time looking at the logs and we have eliminated any flow oriented viariable.
oh, and the clutch isn't slipping. BTW, it looks really nice.
'hopeful of a thawed Hughesnet dish...
howard
12-14-10, 12:58 PM
#310
He did say ALS.
Hate to here that Howard! I have around 10k miles on my reused housings and ALS seals. Comp is still great. Not sure if you remember but I too run a GT4094r. Just ran my best time ever a couple weeks ago. (in sig below). Should be good for a high 9.9 to 10.0 sec. 1/4 pass.
Hate to here that Howard! I have around 10k miles on my reused housings and ALS seals. Comp is still great. Not sure if you remember but I too run a GT4094r. Just ran my best time ever a couple weeks ago. (in sig below). Should be good for a high 9.9 to 10.0 sec. 1/4 pass.
12-14-10, 02:41 PM
#314
Im obviously interested in hearing more about the issues caused by ALS seals as this is exactly opposite of everything I have seen personally. 
Maybe if you could elaborate on why you removed the engine when you had an electrical issue So far something doesnt add up. 
Maybe if you could elaborate on why you removed the engine when you had an electrical issue
So far something doesnt add up.
12-14-10, 03:23 PM
#317
Thanks. Car went 6.49 then backed up with a 6.44. Thought you were already on my youtube list (suscribed) and got the new video's?
So back on topic.
I have 10k miles on mine and 60-80 passes at the track No oil mods, old housing. Just would have thought these would have failed by now if they were eating away at that rate. Car still pulls the same vac as day 1.
12-14-10, 07:15 PM
#319
Thanks. Car went 6.49 then backed up with a 6.44. Thought you were already on my youtube list (suscribed) and got the new video's?
So back on topic.
I have 10k miles on mine and 60-80 passes at the track No oil mods, old housing. Just would have thought these would have failed by now if they were eating away at that rate. Car still pulls the same vac as day 1.
So back on topic.
I have 10k miles on mine and 60-80 passes at the track No oil mods, old housing. Just would have thought these would have failed by now if they were eating away at that rate. Car still pulls the same vac as day 1.
-J
12-15-10, 11:05 AM
#321
Racing Rotary Since 1983
Thread Starter
iTrader: (6)
my net/dish is still not up so i am somewhat handicapped as to taking part in the discussion.
i do not at present have an answer to my significant problem. the engine shows close to normal vacuum at idle but has been progressively losing power with each pull. it started at about 400 rw at 15 psi and is down to 260.
140 horses is alot of loss.
the engine makes boost nicely. (20 psi by 3700 and that was w a boost leak at both secondary injectors... that of course has been fixed).
my view is that we have pressure but either not flow or combustion sealing. the ignition and fuel are fine.
we have checked everything on the intake side... intercooler, throttle plates full open etc. the turbo is in excellent condition. we have also checked everything on the exhaust side.
the only remaining item is the engine. the ports are no different than last year where we made 507 SAE rwhp at 20 psi with, it turns out, a fairly significant boost leak. (worth 2 psi BTW running off the spring). we made over 120 full throttle 2000-8000+ 4th gear dyno runs last year w zero degradation.
i have not dertermined that it is the apex seals however i do not like the housing wear. the motor was perfect when built a few months ago and it now has (light) chatter marks and circumferential scratching. the exhaust ports have nice closing ramps and are of stock width.
no problems lubewise either.
the apex seals are straight at their contact edge and one has a side bend of .0015 which isn't the problem.
this thread is about turbos and we will get there but it is also about learning things. i am not the one w all the answers. life continues to be a journey looking for answers.
once Cam cleans up my housings the motor will go back together w the seals i ran last year and we will continue to look for answers and get back to turbos.
howard
i do not at present have an answer to my significant problem. the engine shows close to normal vacuum at idle but has been progressively losing power with each pull. it started at about 400 rw at 15 psi and is down to 260.
140 horses is alot of loss.
the engine makes boost nicely. (20 psi by 3700 and that was w a boost leak at both secondary injectors... that of course has been fixed).
my view is that we have pressure but either not flow or combustion sealing. the ignition and fuel are fine.
we have checked everything on the intake side... intercooler, throttle plates full open etc. the turbo is in excellent condition. we have also checked everything on the exhaust side.
the only remaining item is the engine. the ports are no different than last year where we made 507 SAE rwhp at 20 psi with, it turns out, a fairly significant boost leak. (worth 2 psi BTW running off the spring). we made over 120 full throttle 2000-8000+ 4th gear dyno runs last year w zero degradation.
i have not dertermined that it is the apex seals however i do not like the housing wear. the motor was perfect when built a few months ago and it now has (light) chatter marks and circumferential scratching. the exhaust ports have nice closing ramps and are of stock width.
no problems lubewise either.
the apex seals are straight at their contact edge and one has a side bend of .0015 which isn't the problem.
this thread is about turbos and we will get there but it is also about learning things. i am not the one w all the answers. life continues to be a journey looking for answers.
once Cam cleans up my housings the motor will go back together w the seals i ran last year and we will continue to look for answers and get back to turbos.
howard
Last edited by Howard Coleman; 12-15-10 at 11:08 AM.
