2nd turbo underboosting??

[ninjasx]

Hi guys,
 I`m back with a rex again but this time it`s an FD:)
I put it on the dyno today and it seems to be underboosting on the second turbo it picks up but quickly drops off and also the fuelling is way off richer than 10:1 and therefore off the scale.
have a look at the graphs, I`m new to turbo`d rotarys, what`s the boost supposed to be, i thought it was meant to be 0.7-0.5-0.7bar. any suggestions on the cause of this?
cheers, Mark
boost:



AFR:



and here`s a pic of my new rex:cool

[ninjasx]

anyone:confused:
Am I right in thinking it`s probably something to do with the rats nest under the inlet manifold?

[scientist1968]

the primary boost looks good, so a leak in the system is unlikely.
From here on its down to the sequential turbo control system, a complex series of actuators and valves operated by shed loads of vacuum and pressure tubing.

If you are looking to trouble shoot this yourself, you will need to do some background reading and work through the possible causes in a logical manner.
Here is a start, two websites that give good explanations of the system.

//www.autosportracetech.com/RX-7

//www.scuderiaciriani.com/rx7/boost_problems.html

Good luck mate, mines been running a 8,7,5 psi pattern (i.e no secondary turbo and low primary). I\'ve spent three weekends messing with it now......i think an expensive trip to a rotary specialist is on the cards.

[ninjasx]

Thanks mate,
I`ll have a look through those sites, I think it may be leaking when the engine gets hot coz the dyno run was done after sitting on the motorway for 40mins, when i took it out last night it was definately not feeling like 200bhp @wheels after 20mins of pootling about warming it up:confused: