I am new to the RX7 and was wondering how something works. I took my rex on its very first long drive last night (have owned it for over a month now). I finished installing my boost and water temp gauge before taking it on the road. I drove over to my girlfriends and on the way I wanted to check the boost gauge(since the water gauge wasnt working-which I fixed this morning-stupid grounding). I do have some mods on my car right now which is why I think I got the reading I did. Here are some of my mods and readings of VAC and boost:

Mods:
Downpipe
02 sensor
High Flow Cat
Racing Beat Exhaust
Pettit Cold Air intake(DONT SPEND YOUR MONEY ON THIS-RIP OFF!!!!!)

Readings:
Idle VAC-15-16-is that a good reading?
When I would slowly accelerate the gauge would come off the boost and go to VAC. Is that right?
I tried to test it in 3rd gear but when I did it, I noticed my boost almost got to 15 so I laid off. I also have the hesitation problem at 3K rpms. I am going to install a manual boost conroller tomorrow along with my power FC (hopefully fix the hesitation problem). I know gauges (i got an autometer) are sometimes off and I was wondering if mine sounds like it is. Should I look for anything? What are typical readings under various RPM condidtions? How can I fix it? Thanks for your help.

 

Well Vacumm will be different at different altitudes. As for your boost pikes, a manual boost controller might fix it but I would recommend putting a electronic one. Deffently install that PFC.

 

15-16in-hg is okay for idle...I'm guessing you have around 70k miles on the motor, if it's orginal.

Pettit's CAI is actually quite good (if correctly installed)...it just isn't pretty.

This statement makes no sense.

you should be in VAC when idling and cruising...during accelarating you can either you will be in low VAC (near 0psi) or LOW boost depending on throttle posistion. WOT you should see 10psi max.

you have something wrong with your boost control...or an ECU tuned for 15psi (but doesn't sound like you have the mods to run high boost), I'd contact the previous owner.

 

Rolling on throttle and moving from vac to boost is normal. Your idle vac sounds like its right where it should be.

The pfc can control boost too, so play with that.

 

thanks for all ur guys help. I just got back from testing out the temp gauge that now works and it was at 190F when I shut it off. Is temp too high? What temps should I look for when driving? I will try and explain what happens when accelerating- if I barely accelerate, the boost gauge will come down and go to VAC about 5-10. Maybe its off alittle. I will definitly play with the PFC and hopefully fix some stuff. Also, why would an electroic boost contoller be better than a manual?(if you guys have a link to which vac hose I am suppose to put it in, it would help alot) Thanks for your help!

 

no it wont... Wastegates, port them or go larger.

 

electronic boost controller, like a Gredy Proffec B, has adjustment for how crisp you want your boost to come on. This helps at transition time to eliminate spikes. Like I said before your VAC reading will change depending on your altitude from sea level. The closer you are to sea level the higher the reading will be.

^ larger wastegate? okay

Porting your wastegate helps but when you have a upgraded mid pipe you want to use a boost controller.

 

the wastegate needs to be ported to run higher boost safely on the stock twins, period. 15-16 psi max, most reccomend 15 max as the extra 1 psi does not yeild much extra power but adds quite a bit of heat. the wastegate should be ported to 1.24" to be safe. IMO a midpipe is a waste on stock boost, 10psi with a mp or hf cat yeilds very similar power levels, plus most people dont take midpipes as serious of a mod than it actually is.

and as far as boost controllers go, do a search and read for 2 years. its up to you which u choose.

p.s. the pfc will clear up you 3k hesitation, not the boost controller.

 

PFC will clear your 3 k hesitation, I forgot to mention that. For the record though, I ran stock turbos with the w/g un-ported with a Proffec B for over a year at 15 psi without spikes and resonated mp and no cats at all. But porting your w/g will help though.

 

Well right now I just want to run 10 psi to be safe(should I still port the WG for future use) because I am driving on stock twins and motor and I also will be driving 2.5 hrs to school every couple weeks. I am getting a fluidyne radiator in and hopefully that will take some of my temps down. Will the PFC take care of controlling my boost. I have read some say that it is and it isnt. Also what should I do to make sure that my engine wont overheat when I take that long drive, any recommendation? I know the obvious(ie intercooler), but I am kinda short on money.

Does anyone know a thread about where to instal the manual boost controller? I know where it goes but I dont know where it is in the engine bay.

 

my god there is too much bad information in this post.

 

I would recommend to port it since it will help. 190 in temp in Ga is not bad. I was seeing 190 with a fluidyne and FMIC, but is a good idea to upgrade it. PFC will controll boost but you have to buy the boost controller for it but don't quote me on that because I'm not 100% sure on that. I know you can though. Follow this set up to adjust your MBC. This also worked for me with just a dp though.
https://www.rx7club.com/showthread.p...erfect+10-8-10