Re: Got my appointment...
 

Ok heres what i decided:
I cancelled the dyno session and the injectors.
I found a good deal on a 50 trim setup that includes a ported and tapped 2g mani, with a tial 38mm wg, VP tubular o2 housing, Dejon Tool Intake pipe and Dejon tool lower ic piping for the 50 trim on the stock sidemount (which wont be used because of the FMIC)
So i figure ill get the best results from the dyno if i get this installed and working before going.
What injectors should i purchase for this kind of setup? (already know im getting a walboro fuel pump)
Thanks,
Tom

Re: Got my appointment...
 

Well for that setup you will probably need those 680s... You just need a way for your ECU to realize you have them- Eprom chip or GM MAFT or AEM..

Re: Got my appointment...
 

If you do all that Tom you would be best suited to just get a EPROM ECU and go with DSMlink.

If I were you and didn't want to shell out a ton of money, I would just throw the FMIC on the car and and say fuck the injectors and just tune it with the stock ones. 2Gs have a better fuel system than 1Gs do, you could go a long way with the 450s and that T28.

Re: Got my appointment...
 

I say use those 680's since you have them and get a Walbro 190 (keep it rewired). This is of course assuming you do get that 50-trim, if you don't just stay with the 450's or use 550's. No point in putting them in before you need them.

Re: Got my appointment...
 

Tom, running 20psi with no FMIC on a turbo that puts out blazing hot isn't the best thing. You really have no idea if it's knocking or not. Not hitting fuel cut means absolutely nothing. Fuel cut doesn't save your motor from knock, detonation, running too lean, blowing up, damage, or just about anything at all.

Contrary to what a lot of these guys are saying, you can probably run the 680cc injectors with your turbo and an AFC and have the car idle and run okay. They are however, much larger than what you need. Running big injectors does not mean you can run more boost safely or anything. Usually you want the closest injector size suited to the power you are going to make. 450s are good to about 300whp, 550s are good to about 400whp. You will have a better chance of getting a good tune out of smaller injectors. More importantly, I wouldn't even bother running to high of boost or getting it tuned until you a FMIC. It's probably knocking like crazy if you are running high boost with no FMIC on the shit ass gas they have out there.

Re: Got my appointment...
 

GM MAFT is no better than an AFC. All it does is try to fool the stock ECU in the same exact way.

Re: Got my appointment...
 

He has a 2G, it's not that easy.

Re: Got my appointment...
 

Thanks again Shane. What i will be doing is going with the 50 trim setup, 680cc inj, the FMIC will be on, WG, etc. Im just gonna say fuck it, go big or go home. Then after all of this is installed ill get it on the dyno and see what it'll do. Ill also look into a dsmlink.

Re: Got my appointment...
 

I like when shane talks, people listen!


-Colin

Re: Got my appointment...
 

off topic, but what size injectors should be used with a GT35R? The car has a stock 6 bolt, FMIC, and all other supporting mods needed. I am not sure if I want to use my 780's or use my 1000's. I plan on running 110 leaded and hopefully 30psi or 25 psi pump. 25psi pump worked well on my car with the old turbo with no knock. BTW, it has dsmlink.

Re: Got my appointment...
 

1000's.

Re: Got my appointment...
 

thats what I though, thanks

Re: Got my appointment...
 

True but you can compensate for injector sizes. Meh worked for me, its not AEM or DSMlink but it works well.

Re: Got my appointment...
 

An AFC and a MAFT try to accomplish the same goal but they do it in different ways. The AFC has more refined tuning points based on RPM and the MAFT has a more raw approach to tuning by using injectors compensation and 4 points of RPM tuning. I guess you could compare a MAFT to a 5 knob AFC on steroids. With the difference being that you can eliminate the stock MAF and compensate for bigger injectors with the MAFT. Obviously there are a few more benefits but you get what I mean.

The only draw back to a MAFT over an AFC is the MAFT uses bionary dipswitch combinations to adjust A/F ratio as well as different combinations for different injectors sizes. Another thing that sucks about the MAFT is that it only uses four different RPM points for tuning. Obviously with the AFC you have a few more RPM points to tune with as well as high and low throttle settings on the newer versions. I think thats the reason a lot of people use the MAFT with the AFC. You get the benefit of running bigger injectors without having to max out your AFC into the minus and you get the AFC to fine tune where the MAFT will not.

For a stock 450cc application you zero out everthing except for the AUX, that you would set to 3. I am not 100% sure but I think the new version of MAFT can compensate for up to 1200cc injectors.

Re: Got my appointment...
 

I was using the MAFT and 5 Knob AFC ;)

Re: Got my appointment...
 

That was my setup too with a 20G, 650cc injectors, and a rewired Walbro 190.

Re: Got my appointment...
 

tom shoud sell his driveline to shane :)

Re: Got my appointment...
 

With an AFC you compensate for 650cc injectors by leaning out the low and high throttle by 30%. So the AFC interupts the signal from the MAS going to the ECU and lowers the signal amount by 30%. With the MAFT, you set the dipswitches to 650 injectors, and it interupts the signal from the MAS going to the ECU and lowers the signal amount by 30%. They do the same damn thing, the MAFT isn't any better or safer than an AFC, it just lets you run a GM MAF instead. Unless you change the code directly inside the ECU, you are just tricking something somewhere.

Re: Got my appointment...
 

Just to claify, I consider a car 'running like ass' when it doesn't know which timing map to run it, which is usually a result of to much correction needed of the airflow signal.

Re: Got my appointment...
 

What I was kind of getting at was:

If you have to lean out the AFC by 30% with 650s just to get the car back to normal then that leaves you about 20% of tuning on the lean side. The bigger the injector that worse you are going to have to go into the negative. With the MAFT in conjunction with the AFC you can zero out almost any injector size you are going to run and then still have 50% on the plus and minus side of the AFC for fine tuning.

If you use the MAFT on its own then I agree its just a matter of picking your poison, both are trying to accomplish the same goal. They just do it in different ways. I would feel safer with an AFC since its a lot more refined but on the same note its a lot more limited to how much fuel you can take out to compensate for bigger injectors.

If somebody can show me a 2G that is running 1000cc injectors with a stock ECU and a AFC I will stand corrected.