http://cgi.ebay.com/ebaymotors/AFC-F...12439858QQrdZ1

Also look on the following web site, the manufacturer of the Mini AFC 2.2 (go on the support section, install instruction, engine electronics, afc 2.2).

http://www.easyperformance.com/

I talk to the seller. They did some testing on a Ion Redline, but no dyno results yet. They will probably have some test results (done on a Cobalt SS with a 2.8 pulley) within a week or so. EvilcobaltSS (on ************* forum) is the man who is testing the unit on his SS/SC. Hoping he will give us some results soon ...

Since I don't know if the stock injectors are already at their maximum flow at WOT with a smaller supercharger pulley, I cannot be sure if the Mini AFC will get the job done. Even with the PSI-FI kit, I have whitnessed some lean condition at WOT on a Cobalt SS with a wideband sensor.

 

There is another good thread about this a few spots up.

But the car may benefit from some sort of boost-a-pump type piece. They really help out with Grand Prixs and Cobras. Something to look into. Would probably work wonders with this piece, assuming the injectors still have some left in them.

 

Price has been dropped from 180 to 160 $ on E-Bay.

 

throw some larger injectors on if your in doubt.

 

If I found some, I'll put some 42 lb/hour (440 cc/min), exactly like those of the Stage 2 !

 

Wow those are big! What size are the stock ones?

 

42#/hr?! that is massive. GPs use that but thats a big step up. Stock GTP ones are 36#/hr. I too wish to know stock injector size

 

Stockers are supposed to be 355 cc/min (34 lb/hr).

 

Don't forget that our car have only 4 injectors, a GTP got 6 ! That's why a SS have larger ones.

 

Bingo!
Dont forget if you go to most readily available performance injectors (Like RC Rngineering or Linder) You will also need to replace the stock Multec connectors wth Bosch connectors. You can usually find the Bosch pigtails on eBay for about $5 each.
BUT
Why wouldnt you just wait for the Stage 1 to get injectors? That way you get all the benefits of the reflash as well!! It's going to be difficult to tune any sort of AFC or other device to compensate for the larger injectors on the factory tune.

WopOnTour

 

Firstly I'll tune the most I can with the AFC 2.2 on stock injectors, then will see which results I will get. I've already order also an Aeroforce Interceptor gauge (Cobalt SS Edition); it will help for tuning. Maybe will get also a stock injector out to get the flow measured. Thanks for all the advices.

 

OK sounds good-
BUT remember most people are not showing (on either dyno or in-car WB02) that they are even close to being "dangerously" lean- even with the PSI-FI kit. Most (including yourself) are reporting high 11s to mid 12s as their "leanest" air fuel ratio at the top end. This is supported by the absence of any discernable knock or registering ANY knock retard on the TECH2 during repeated 1/4 passes or dyno pulls. Actually the only snapshots where I HAVE registered/recorded KR in a TECH2 snapshot was if the rev limiter was hit in 1st or 2nd-and the mechanical rocking/clanging/banging of the engine itself was enough to induce a few degrees of pull out.

So given the mid 12:1 AFRs people are seeing, certainly the larger injectors themselves wont be able to "make" much more HP (if any) but instead allow other improvements to do so!(such as the higher rev limit, re-optimized timing curve, and additional boost via the Stage 2 pully) So I still think you're gonna want the Stage 1 recal and it will still represent the best "value" - assuming you're not getting these new injectors gratis somehow.

Dont let us deter you though Jean-Marc and please keep us all updated as to your progress.
Regards
WopOnTour

 

My WOT fuel ratio was roughly 13.2 with the 3" pulley, catback, header and CAI. When being stock it was roughly 10.8.

ADDED: The 13.2 air fuel ratio has been noticed on the very first dyno pulls after the CAI and header installation, but each dyno pull after should have been richer down to roughyl 12.5, as said by WOP.

I am supposed to install as well my Mini AFC 2.2 and the Aeroforce Scan Gauge (if I receive it until friday).

Will probably try some Denso Iridium plugs too and some higher octane gas (more than 91).

 

Yesterday, we've done one full hour of dyno tuning, and as expected the Mini AFC 2.2 works ! It allowed to fine tune the air fuel curve, even if the stock injectors haven't a lot of room to play with them. Even without any tuning from the Mini AFC 2.2, the stock PCM still seems to keep the air fuel ratio not higher than 12.5 at WOT.

I didn't receive my bigger injectors in time for the dyno tuning session. So we doesn't measure any fuel pressure or neither the stock injectors flow. About the bigger injectors, maybe I will need them only with an even smaller pulley than 3".

Here are my current setup as tested yesterday :

2,5" catback
3" pulley @ 15.2 PSI
SCdyne Header
Denso Iridium #IK20 Spark Plugs (gap 0,035")
K&N high flow filter #RU-2710 with lower lid removed

We also get the Aeroforce Interceptor gauge installed, but unfortunatly the cable they sent me caused an interface conflict with my SS PCM. So we haven't been able to get the gauge work properly, neither measure the Injector Pulse width for the stock injectors.

Results: We consistently went to 222 WHP and 192 WTQ; giving 285 SAE BHP and 245 TQ.

My previous setup (with CAI, but without Iridium Plugs and without Mini AFC 2.2) was roughly 212 WHP and 185 WTQ.

When we compare the current setup to my stock dyno runs of 190 WHP and 170 WTQ, that's a 17 % increase in HP and 13 % increase in torque.

Have a nice day !

 

Could yuou give us some numbers from the 2.2 that you set it at so we can have an idea of where to start at with our tuning?

 

Here are my numbers, but yours WILL HAVE TO BE different than mine, since my car is in Quebec City, Canada, with coldest temp and probably different altitude than yours in New Mexico with much more hotter temps. Gas octane rate and each different engine mods will have an effect on teh airfuel ratio too.

Here are my best numbers as I can remember ... we adjusted mine in advanced mode, since it can be tuned differently for all set points.

1000 to 4000 Hz : 100 % (No correction)
5000 Hz : 98 %
6000 Hz : 96 %
7000 Hz : 95 %
8000 : 95 %
9000 : 95 %
10000 : 96 %
11000 : 97 %
12000 : 98 %
13000 : 100 %

I tried a lot of combination, going as low to 88 % for mid RPM's (too lean !) an as high as 103 % at WOT (too rich), and all I have to say is that device definetly works !

As an example, going to 88% at mid RPM's gave a LEAN air fuel ratio of 15. 8 @ 4000 RPM's, so you have to be VERY CAREFUL on the tuning !

A wideband sensor MUST be used.

Have a nice day !

 

Thanks update us when your new injectors come in and how they work. Any codes from it?

 

No codes yet. For the injectors, maybe I will not install them with the 3" pulley I run actually.

 

dont use iridium plugs. SC cars dont like them. Use plain old copper plugs for the best performance.

 

Kenne Bell (who sells good Supercharger kits for high HP mustangs and other high performance cars) quote that the Denso are the best plugs they ever tested. All I can say is since the installation, the engine runs smoother and there are no more "bogs" at cold temperature.

Quote :

What spark plug should I run with a supercharger? One heat range cooler than stock. Denso Iridium is the best plug we've ever tested. Avoid Platinum plugs. Always set gaps at .035". Denso irridiums are factory gapped at .044".

 

I bought my Mini AFC 2.2 from Aftherthoughts Auto ...

The model they sells is for the GTO, but they have to modify it to fit our Cobalts or Redlines.

http://www.afterthoughtsauto.com/mini-afc.html

The connector type is the 55NST (5 pins to 5 pins MAF, some 2004+ cars).

 

nm, youre right. I was thinking platinum when i read your post for some reason.

 

I am searching the forums for advice/experience with tuning devices for the cobalt SS S/C's. I"ve never seen this one before, but looks to be adequate for adjusting air/fule ratio's...assuming you know what you're doing. Anyway, I was wondering if anyone has had any experience with the APEXi S-AFCII. I know it's more expensive, but I"m pretty sure it has more capabilities. I"ve also heard that the stock ECU compensates when you adjust the fuel trim, so it's pointless. Any opinions??

 

Revitup tested the Apexi S-AFC II and said that the car didn't like it (threw CEL and codes).

 

yea...this is generally what i am hearing. any word on the greddy e-manage?