Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: rising son on November 28, 2011, 10:23:07 PM

Title: standard boost
Post by: rising son on November 28, 2011, 10:23:07 PM
sorry i posted this a week ago with no answer so thought id try again as really needing to know but cant find an answer anywere...
whats the standard boost of an fc turbo II in psi ?
Title: standard boost
Post by: m1tch on November 28, 2011, 10:36:09 PM
Its 0.6bar, so around 8-9psi or so, stock fueling and turbo are ok for about 0.9 bar before things start going wrong lol - most chipped ECUs run the injector duty cycles higher and allow fueling to 0.9bar, although you need to make sure that the fuel pump is ok else the engine will go lean and then fail making expensive noises.

Make sure you get a MECHANICAL boost gauge to find out what it running at :)
Title: standard boost
Post by: rising son on November 28, 2011, 10:39:13 PM
my aftermarket boost guage says shes running 5psi, i have a boost controller also along with other mods anyway, thought that was a little low, maybe try turning it up to about 10psi then if thats safe.....
Title: standard boost
Post by: m1tch on November 28, 2011, 10:42:42 PM
Quote from: rising son;800551my aftermarket boost guage says shes running 5psi, i have a boost controller also along with other mods anyway, thought that was a little low, maybe try turning it up to about 10psi then if thats safe.....

5psi sounds like its on spring boost (the boost that the OEM actuator is set at) I would check for a boost leak somewhere in the pipework, don\'t up anything until you check for leaks, there might be a split hose somewhere which is why its not boosting.
Title: standard boost
Post by: rising son on November 28, 2011, 10:45:59 PM
hmmm, theres none of the tell tale signs of a boost leak but yea i will check before touching anything.... the guy told me he had turned the boost down when i bought it... will get a look now that i know the figures
Title: standard boost
Post by: m1tch on November 29, 2011, 07:47:56 AM
Ah ok, if he has turned it down that makes sense, you can\'t turn it down lower than the wastegate spring lol do you have a decat and free flowing exhaust? If so you need to make sure you have a ported wastegate on the turbo to stop boost creep.
Title: standard boost
Post by: rising son on November 29, 2011, 04:51:21 PM
yes he "said" hed turned it down... maybe he was hiding a leak tho.... yes i have decat and full kakimoto system from turbo back, not sure on solenoid, but have a boost controller... surely the boost would still creep even set at 5psi if i didnt have the ported wastegate... which its not doing... im really struggling to get my head round these cars.. they seem simple enough, but trying to even get a decent look at the turbo when its on the ground is tricky....
Title: standard boost
Post by: no_boingers on December 01, 2011, 08:08:45 AM
Quotethe engine will go lean and then fail making expensive noises.
Hmm there it is again... please is there any evidence that these engines go bang when they run lean on fuel?  Or is this simply an urban legend.

If they do go nuclear due to lack of fuel then can someone please explain to me exactly what happens?


(p.s. sry to thread-jack!)