Ok I'm trying to figure out what boost pattern my '93 stock RX7 should have. Some things I have read says 7psi on the first turbo followed by a brief 10psi on transition to the large turbo then settling down to 7psi again toward redline.



Other things I've read say 12 psi on the primary followed by a brief decrease to 10psi on the transition followed by 12psi to redline on the secondary turbo.



Which is correct?



Thanks,



John Magnuson

 

John,

I spoke with Peter Farrell racing last year and asked them the same question. According to their shop,

the turbos come 8 to 10 psi from factory.



The first turbo boost at 8psi from 3000rpm through 5000, it then closes while the other has spooled its compression to 10psi. The secondary then opens for a short time, back to 8psi. This all happens between 3000 to 5500 rpms. Which is your powerband on the 3rd gens.



But, don't take my word for it. Call Peter Farrell's shop, he has proven to be the Rx7 Guri of motorsports.



http://www.pfsupercars.com/



Good luck.



Luis

 

on sequential setup...

10psi on the primary.....requires at least 8psi for the secondary

8psi on the transition...

peaks again at 10psi on the secondary...

to hold on 8-10psi on the secondary till redline....

take my word for it....



3rd gear at WOT to generate these results is ideal..

 

*cough* *cough*

 

Ok... so since my car sometimes briefly hits 14 psi at certain times right after I slam the throttle down while moving (like coming out of corners) this means something is wrong even though it settles back down to 11 psi?



Thanks,



John

 

it shouldn't spike that high...........

 

over simplified it should be 10-8-10

depending on your mods it might creep or spike higher, 14 is a bit much

 

stock is 10-8-10 but if ur car is running that pattern id run out and buy me some lotto tickets cause u pretty lucky. downpipe and intake will easly put u at a 12-10-12 pattern which i liked a lot cept in the winter when it seems to spike up in the transition. make sure ur vac lines are all set and u should control the spiking pretty well but the cold can mess wth us pretty good.

 

Uh-oh... I regularly see 16 psi on my reman motor, original turbos, installed by a certified rotary tech @ a mazda dealer. Lately, I've seen an 11-9-13 pattern @ 5300 ft. elev.





Time for a boost controller....



I should revise - all this, and my A/F meter is buried DEEP into rich territory.. in fact, when I floor it, it won't come off of 10:1, till I let off. I know this A/F meter is only good for showing rich or lean, but it's pegged deep into rich.

 

you need to look at the manual it has a boost test that you do in 3rd gear.



mike