neit_jnf

iTrader: (17)

I temporarily installed an Autometer mechanical boost gauge to the extra nipple in the UIM and got it in through the passenger window, I just wanted to check my car's boost.

My power mods:

M2 Stage 3 ECU
Adam c cheap bastard intake with dirty OEM filter

nothing else... my first mod was the ECU 'cause I didn't want to take any chances

In second gear it's doing 12 - 8 - 11.5 aproximated because the dip is too fast plus I was alone in the car and can't keep my eyes glued to the gauge while accelerating

In 3rd gear it's easier to see and it's doing 11.5 - 8 - 11.5; again, the dip is too fast so I can't really tell if it's 8 or 9 all I know is that it's below 10

The idle vacuum is 18-19 mmHg

Cruising at 50 mph in 5th gear vacuum is 13 mmHg

Also I could hear the gauge leaking air!! I'm worried that I may be boosting too high, at least I have the ECU to protect her.

My next mods are going to be efini y-pipe, jet-hot coated ssautochrome downpipe, RB duals and clean air filter

It's going to be VERY VERY interesting when I finish...

adam c

iTrader: (2)

Those are good numbers. Good boost on the primary and secondary. The stock (or modified stock) ecu will try to keep the transition at around 8, which is just fine.

Your next mod should be a clean K&N air filter The stock filter is a bit restrictive. You will feel a difference in performance.

BlueRex

Agreed! It's cheap in comparison to the rest of the mods. Just do that first so you don't have to worry about it later.

neit_jnf

iTrader: (17)

I already got the DP, it came back from jet-hot today! I just need to install it or have someone do it for me... Do you think any around-the-corner exhaust shop can do this install or should I wait and take it to rx7store or banzai racing? (3hrs drive from each) I don't know if this is something I want to try myself...

BlueRex

I'd say that ideally that you'd want to do the work yourself so you know it's done right, but if you're not mechanically proned then I would say take it to a shop that works on RX7's. There are always complications a normal muffler shop may not be aware of (like the special care needed when removing the studs on the manifold).

Maybe there is a forum member in your area who can help out.

adam c

iTrader: (2)

If you are a pretty good mechanic, you can do the DP yourself. If you are unsure about it, take it to a professional. A lot of things can go wrong with a DP installation, so you need to know what you are doing.

wtgator69

I am not a very good mechanic and I did the DP myself (my first mod I did myself) and it wasnt terribly difficult. Check this link out: http://www.scuderiaciriani.com/rx7/d...e_install.html

alberto_mg

buy yourself a boost gauge as you will be making even more boost after installing that downpipe. you always wanna keep an eye on boost levels.

Addict

Yeah, definately get a permanant boost gauge.
Downpipe was the first thing I added(former owner already had added boost guauge) myself, and I'm NOT mechanically inclined. I just took my time, used lots of PBBlaster, and read write ups from here.

neit_jnf

iTrader: (17)

I forgot to ask... Do the M2 ECU increase boost? Or is it 11.5-12 because of adam c's intake?

chiminoid

the increased airflow from the intake. last time i checked, FD ecu's don't actually ~control~ boost.

DamonB

The ecu DOES control boost via the wastegate solenoid which controls the wastegate actuator.

chiminoid

sorry. i was under the impression that it didn't and that's why boost controllers are greatly needed on this car to keep the boost at what the ecu is tuned for - whether it be stock or 20psi

Snook

iTrader: (12)

my first deal would be to get a boost gauge that isnt leaking and see what boost you have
then get a clean k&n and check it again

the dp is going to be a big step for you if you are already boosting 12psi
you dont want to go over 12 thats bad

adam c

iTrader: (2)

The stock ECU is set to keep boost at 10 psi "IF" everything is stock. The ECU will not keep the boost at 10 psi when you start modding the car. It can't be used as a safe boost controller for any of us with multiple mods. It wasn't designed for that.

neit_jnf

iTrader: (17)

But I'm not using the stock ECU... So if I want to lower my boost I'm going to need a boost controller? Bah! More money to spend

Kento

No, it isn't, but that's not what Damon meant. The ECU does sense and control boost. All of the remapped ECUs (Pettit and M2) I've seen on FDs have their boost set at 12-13 psi, since that is the accepted limit for proper fuel delivery from the stock fuel system. Thus, they'll give (a little more or less, depending on the flow characteristics of the intake and exhaust that each engine has) that amount of boost usually up to the point of installing a mid-pipe, at which point the wastegate becomes overpowered by the flow of the engine, and boost increases. Other than that, however, most of the time an M2 or Pettit ECU is capable of controlling boost with most of the normal bolt-ons, excluding a MP, as long as the sequential control system is functioning normally.

adam c

iTrader: (2)

Kento,

When I got my M2 ECU & M2 downpipe, my boost was about 12 1/2 psi, as measured by Kyle at M2 with his external boost gauge (run thru the passenger window). I did not have an installed boost gauge at that time. Before installing a boost gauge (dumb on my part) I installed an efini y-pipe, and my Cheap Bastard Intake mod. I then installed my boost gauge, and found that I was boosting to 15 1/2 psi. I immediately installed a boost controller. The M2 ECU was not controlling boost. This was with a stock main cat and stock catback. That is why I say that the stock ECU doesn't control boost very well.

Kento

That's why I was emphasizing usually, depending on the flow characteristics of each engine. Perhaps your car is above the norm. Perhaps there is also the possibility of calibration/measurement issues between the time Kyle measured your boost, and your own boost gauge? I've ridden in three other FDs that had remapped ECUs, and all were boosting at a maximum of 12-13 psi (all measured at the UIM nipple) with different stages of bolt-ons (excluding a MP), with no boost controllers.

That said, I don't think boost controllers are a waste, or that the stock ECU is very precise in its control.

adam c

iTrader: (2)

Kento,

Perhaps my car is above the norm. However, boosting to 15 1/2 psi with a stock cat & catback is pretty high. Even if there is a calibration difference between boost gauges, I wouldn't expect more than a 1 psi difference. My car requires a boost controller with the M2 ECU. I "suspect" that other cars with my mods would also require one.

neit_jnf

iTrader: (17)

Installed the gauge properly now with hard nylon lines tee'd at the map sensor and I'm boosting 12.5 with all stock exhaust. I'm planning on the y-pipe, DP and CB and I fear the boost will be too high

adam c

iTrader: (2)

It almost certainly will go too high. I didn't want to spend a bunch of money on a boost controller either. I installed a manual boost controller for about $10. I have found it to work very well. Here's a link:

http://www.rx7turboturbo.com/robrobi...controller.htm

Do not install the prespool controller.

Snook

iTrader: (12)

dont get those shitty home depot valves though you can make your own ball and spring valve for about 15 dollars and the car spools 2-300 rpms faster and holds rock solid!

Also, Dont frigen T anything to your map sensor line please


Yanni

Sonny

With the mods in my sig and no boost controller, I would spike up to 15 psi after transition. M2 does not recommend more than 12 psi with their ECU (maybe they are being conservative). I got my Hallman EVO Rx and it's a steady 12 psi now. I plan on getting a second one for the precontrol gate ala Damian.

Sonny

neit_jnf

iTrader: (17)

Why not? I searched in the forum for best location for the boost gauge and most people agreed this is the best one as you can see what the ECU is really seeing. With the UIM nipple my boost gauge read 1 psi lower.