Custom chip and bigger injectors?

Tomas · 10-30-2002, 04:59 AM

Hello

I have a small question. For the moment i have Accel 30lbs high impedance injectors with a custom chip burned for my injector size. What happens if I change to 55lbs low impedance injectors with the same chip that i have burned for 30lbs? Will it work? What happens?

thanks

regards

Tomas

vvv90 · 11-04-2002, 07:09 PM

Not if you want to drive around with black smoke spewing out the back.
From the look of your setup though, you should be tweaking the computer for any change you do.

[Modified by vvv90, 4:10 PM 11/4/2002]

Tomas · 11-05-2002, 04:34 AM

Hello vvv90

Lots of tuners has told me that I have too small injectors now. 30lbs will handle approx 500hp. I havent dyno my car but if calculate my ET/weight I has to have around 500hp. This winter i gonna tune my car more so thats why i gonna go for bigger injectors.

Tomas · 11-05-2002, 05:11 AM

Will my stock ECU handle low impedance injectors?

vvv90 · 11-05-2002, 04:30 PM

go to http://www.tpis.com

Call them and ask, they won't steer you wrong. How much HP to you expect to be putting out though? I still think going from 30's to 55's is a pretty high jump. But you're absolutely right, it's all about the HP.

:cheers: :cheers: :cheers:

Bruce · 11-06-2002, 02:38 AM

You can not run 55# injector it will burn up your ecm. Max is 50s for stock computer.

Bruce

dgoodhue · 11-07-2002, 11:35 AM

Just looking quickly at your setup and time slip, it looks like your runing about 116 mph (this is 1/4 mile track, right?). This look to be around what a 383 SR run which is around 430-450hp. I think you need some more tuning as I would expect a 355 S/C would to make more power than a 383. You could probably use larger injectors than 30lb/hr, but your probably not running out of fuel yet with the FMU and the hp your making.

vvv90 · 11-07-2002, 12:16 PM

You should also slap a D-1 on there and up the boost to about 20! :D :D

That should help too. However, after looking at your setup the only weak link I can see besides the U-joints maybe is your crank if it's stock. You should have no problem getting insane amounts of power with what you have already. What's your inevitable goal for that car?

:cheers: :cheers:

Tomas · 11-07-2002, 04:37 PM

Hello vvv90

Unfortunately the crank is stock, but it is balanced. I have heard that a balanced stock crank is good for approx 650hp. My Goal next summer is low 11s. Just with new tires and good grip i think i can hit 11,50.

A new D1 blower should be nice so I can have more boost, because now I have the smallest pulley for 600b blower

regards

Tomas

vvv90 · 11-07-2002, 07:06 PM

cool. :cool:

Don't get me wrong, stock cranks are pretty strong. It was more or less a compliment, because if a stock crank that can take 650HP is your weakest link, you're definitely doing something right. I got the P1SC so that I can upgrade it to the D1 when I eventually reguild my bottom end. But that's still gonna run me $1000 to get it upgraded.

BTW: how many vettes do you see in Finland?

Tomas · 11-08-2002, 04:53 AM

Hello vvv90

Im not really sure how many vettes there are in Finland, because im coming from an Island called Åland that belongs to Finland but we have our own laws, flag, stamp etc and we speaks swedish. On Åland there are 14 Corvettes. And that is quite good if you see how small our Island is.

regards

Tomas :lol: :yesnod: :seeya

dsagers · 11-25-2002, 10:44 PM

What happens if I change to 55lbs low impedance injectors with the same chip that i have burned for 30lbs? Will it work? What happens?

Above answer is correct, you will fry the ECM.

Low impedance injectors are 3 to 4 ohms, the factory ECM and injetors are high impedance - 16 ohms.

Also, the low impedance are a peak and hold where the injectors receives a jolt of some 2 amps to open it and then the signal backs off to .5 amps to hold it open.

The factory stuff is a saturated system. High signal all the time, no peak & hold with the facoty stuff.

A couple options. One is to find an Accel VIC controller. This unit takes your factory injector signal and converts it to 8 low impedance, peak & hold signals. Plus each driver can be adjusted up to 25% to individually trim each cylinder.

Usually see them on ebay for around $300. For insatnce,
http://cgi.ebay.com/ebaymotors/ws/eB...tem=1872718571

Next option is to use an additional injector controller. This unit will switch on additional injectors at a pre set RPM, load or boost.

The additional injectors are usually placed behind the throttle body blades and can use either the low or high impedance style, all depends on the system you buy.

HKS has very nice, but expensive ($800) tunable unit. Some of their older versions are more than adequate, just not as many features. Also, much less money to buy.

Another thing to keep in mind. Low impedance injectors respond faster than saturated injectors and have a much shorter minimum open time. This is the reason you can run 58 lbs/hr low impedance injectors on a small block without flooding the engine at idle.

If you put say, 42 bs/hr saturated injectors on a small block, it will be very rich at idle because the high impedance injector is rather slow compared to a low impedance injector.

dsagers · 11-25-2002, 10:53 PM

Here is another option. Not as big as you want, but use an adjustable fuel pressure regulator and you will be close.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=1873348405