Opps meant miscellaneous whatever but maybe seriously erotica to us car enthusiasts ! LOL On a more serious note want to put forth several answers to last couple of threads about whatever.

1. Your 3/8" fuel line can support 1000 HP no problem.
2. 1985 thru 1993 Vettes (simultaneous or bank fired injection) can run
63 lb/hr injectors without any issues and pass emissions tests.
3. 1994 thru 1996 Vettes with sequential injection can run much bigger
injectors if needed.
4. Using bigger than needed injectors makes tuning a little tougher.
5. Using the proper size injector with a proper tune eliminates the need
for the FMU although I have no issues with using the FMU.
6. Much of the above may seem opposite to what I have printed in my
C4 Semi-White paper. That's because when I shared my thoughts
back then there was no TunerCat or TunerPro software programs
available to us. We have made so much progress on our ability to
edit the C4 ECM/PCM that today I would say the stock computer can
do whatever you need to do !
7. I prefer MAF sensor over S/D simply because easier to tune and
more forgiving AND because today we can buy new style MAF
sensors that can support virtually any HP we can possibly make.
8. On a distributor style car (i.e., all C4's) with 8 plugs you must have
a CDI style ignition above 5500 engine rpm. At 5500 engine rpm and
above there is simply not enough time for the ignition coil to saturate
and fire at 12 vdc. A CDI system raises the 12vdc to about 400vdc
to fire the coil which is more than adequate for 8 cylinders at 5500
rpm. The CDI system is much like the audio amp - you cannot make
enough watts at 12vdc to go boom-boom with your subs. Modern
high power auto audio amps raise the operating voltage just like the
CDI system does. Alternate solutions to the CDI is coil over style
systems.
9. The ATI Super Damper I sell has 6 ribs for the GM belt and 8 ribs as
an accessory belt for the likes of a supercharger. You can use this
damper for any 1992 thru 1996 C4 with or without a blower. If you
have bought the ProCharger LTx kit by all means replace the damper
with the ATI keyed SuperDamper. And why not buy my ATI damper
with the extra 8 ribs - just in case ?
10. On L98's I often recommend an 8" crank pulley to allow running
bigger blower pulleys to reduce chance of any belt slip.
11. My slotted blower pulley makes a 6 rib work like an 8 rib if not a 10
rib.
12. No matter whether you run the booster pump or not the stock
in-tank pump should be upgraded to the 255 L/hr along with the
Racetronix wiring harness. If you want to support about 900 HP
add the Walbro 392 in-line pump and power off the Racetronix
harness. That's my preference for being the cleanest, most quiet
and least complicated fuel system to support a 1000 HP. Can it be
done with dual 255's in-tank? Sure but not my preference for many
reasons.
13. Plugs 2 heat ranges colder good to go. In fact you should run the
coldest plug that does not foul. CDI here a big help. Gap typically
.030" max. I like the NGK Irridiums. On the CDI I prefer the analog
style like the MSD Marine units that are fully potted and use higher
quality components than the typical MSD-6. Of course with any
CDI module you must run the spiral SS wire over carbon core
ignition wires.
14. Finally, if you will allow the engine to go into "closed loop" (you
don't have to) I strongly recommend the 4 wire O's. The 4W O2
has a separate signal return ground. Especially important with
ceramic coated headers which are not milli-volt friendly !!!!!!

I'm tired !!!!!!!!! If I missed some questions forgive me - it's time for my beer !!!!!!!!!!
greg

 

Greg, great write up. Definitely the most frequently asked questions for c4 FI applications.

 

Ok, a few questions;

1) What spark plug wire set do you recommend specifically.

2) on MAF, what aftermarket MAF sensors are available for our application?

3) your HP rating for the fuel system, I assume the 900-1000 HP figure is at the flywheel, and not at the wheels? 3B) can a larger injector be used with the same fuel pump combo to switch to E85?

 

Hi MN !
> On the ignition wires almost any brand as long as the wire has the SS spiral wire over the carbon core. MSD, Accel, Taylor etc. 7mm is fine no need for 8 etc.
> On the HP yes that is flywheel. That combo of pumps (340 & 392) has made 600 RWHP.
> Alcohol needs more flow. The Racetronix website shows some new very awesome pumps that would be more than adequate for E85. Or you could run a voltage booster on the above pumps and increase flow by more than 20%. The easiest and best way to test is simply the electronic fuel pressure gage. Pressure flattens or falls with a rise in boost you need more pump or more something !

 

Nice writeup greg.

Expect a check in 3 weeks for my nice lengthy invoice we have been emailing about.

-Travis

 

Greg

Regarding points 3 & 4 in a 1995 engine with no more than 7-8 lbs boost and under 6,000 rpm, are Siemens 60# injectors too large?

I tried to find pricing for your 6 rib pullies on your website but couldn't find it. How much is a 3.125" 6 rib?

Jim

 

Hi MGB ! Since a sequential only fires once / 720 degrees down low the 60 is like a 30 on a bank fired. So if I was you I'd install the 60's (63.5/lb hr) !

My pullies are $149 for non slotted and $199 for the slotted. A pulley requires a matching collet at $49.00. The collet may be moved from one pulley to another.

greg

 

Thanks Greg

Jim

 

I have run 80 and 115 lb high imp injectors on 730 ecm no problems, however i do not know if it affects emissions, but air fuel was easily controlled to whatever i wanted. No issue with low pulsewidths. This was a mild 400 and an aggressive 400