hci curiosity

donnie84

New Member
Oct 2, 2004
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hey just wondering if any of you guys runnin an h/c/i got a dyno tune or chip burn or if u just run larger injectors. is a tune needed or is it ok to run with larger injectors and a maf tuned to them? also, does anyone know how much a h/c/i plus injectors and maf install would cost? the heads would be asssembled but obviously wold need to put the pushrods and roller rockers on.
 
dyno tune/ custom burnt chip would be the way to go... you can buy new injectors and a MAF calibrated to them, but if you want the peak performance out of them, id get a tune....you might also look into a PMS type thing so you can tune it yourself. i have no personal experience with them but ive heard good things
HCI just for the install? or HCI including all the parts?
id imagine about $1000 for the HCI excluding parts (MAF and injectors will be off anyway so the install is part of the HCI anyway) i would maybe try doing it yourself. i have done it about 4 times since feb and its not too bad... heres a webpage for you that has step by step how to for the HCI http://users3.ev1.net/~voodoostang/headsswap.htm
as for HCI including parts it really depends on what brands and things you go with


hope i was helpful
 
The older fox guys have more luck running without a tune due to their computers. Once you put a decent cam in our cars, a tune is needed. And please dont waste your time(imo) going back to their computer, just upgrade ours and be at a better performance level.

The install price would be a lot i would imagine, i would suggest doing it yourself also. Or try to find someone who has done it who u can throw a couple bucks and beers at who will help "guide" you threw it. Its really simple once u do it once.

I run the PMS and really like it cause its really simple to use.
 
will i get pinging if i just upgrade my injectors to like 24lbers with a maf tuned to them? itd be ok if im runing rich for a bit until i can get a tune, i just dont wanna be pinging.
 
Install for all that could be as much as 2 to 3 thousand bucks (maybe more). That is, unless you find a friend or someone willing to do it on the side for a deal.

Call a few speed shops around you to see what they say.
 
donnie84 said:
will i get pinging if i just upgrade my injectors to like 24lbers with a maf tuned to them? itd be ok if im runing rich for a bit until i can get a tune, i just dont wanna be pinging.


Pinging is caused from pre-detonation. Im not sure how bigger injectors and maf would cause that. Im not sure if pinging is actually being lean...but i do know its not rich. On the stock engine, the upgrade would be a waste of money. There are guys who squeeze the 19's out on h/c/i combos i believe.
 
i am in the process of acquiring a new motor with heads and a cam but unfortunately the stock intake, injectors, maf and stock computer will also be on it. honestly at this point if it will idle and get me a couple miles each way to and from work i will be happy.

it all depends on how big a cam you run and how your particular computer deals with it. it looks to me like a few people get lucky with their cammed 94-95s, but for the most part our computers just dont get along with much.

as for pinging it is pre-detonation like nmcgrawj said, and i believe that is atomized fuel igniting before the spark plug fires. it pings because it is not a clean effiecient burn of all the fuel but only a small amount of the fuel in the cylinder burning at a given moment.

bigger injectors wont help that (at least it wont to my knowledge) unless the fuel system is far too small to keep up with fuel demand.

the best way imo to stop pinging is to clean the maf frequently, run proper octane and dont get carried away with the timing. and if it does ping, stay out of the throttle til you get it corrected.


it will be a long process for me to get my combo all together and running to its full potential, but i had no choice as my other motor apparently doesnt run well under water :( ive searched around a bit and it seems not many people throw in a 306 with a 490/510 cam and afr 165s and reuse the stock intake, squirters and maf so i may be a guinea pig i guess, but it should run and drive and at the moment that is all im hoping for
 
I think the poster's original question about bigger injectors was really directed at doing an h/c/i, not doing an MAF/injector on a stock motor.

On that note, and h/c/i set up will certainly introduce more air into the combustion chamber than a stock setup would have. So given no change in your fuel delivery setup, and no custom tune, you would surely be leaning out a bit at WOT.

I think you were asking whether you could get by without a tune and without bigger injectors, or would you need one or both to keep it safe. I don't know whether you could. It will probably depend on how aggressive you intend to go with the H/C/I, especially the cam. At a bare minimum, you could pick up an adjustable fuel pressure regulator, so you can dial the fuel up a bit.

The other reason (outside of getting the A/F ratio in line) that folks go with a custom tune is that our computers do not deal well with the vacuum changes resulting from an aggressive cam, and idling becomes an issue. Bigger injectors will not correct the idling issues.

If it were me, I would get bigger injectors and a calabrated MAF. Then you can hold off on the custom tune and get it only if you find that you really need it.

I went with a cam from Anderson Ford Motorsports in hopes it would be just a little milder, and maybe I won't need a tune. Still working on that project, so I don't have any feedback from my experience, yet.
 
thanks guys. grgt, you hit hte nail on the head. i wanted to hold off on the tune by getting the calibrated maf and 24lbers. i actually want kind of a mild hci, gt40p heads or gt40y's, either an eddy performer or a cobra intake or gt40 intake (would get those ported proly at a later date, tmoss?) and a frpp e-cam. then 24lbers, a maf, TB and maybe a bigger intank fuel pump. i wouldnt want to have to get a tune for that, but i hopefully would see about 260 or more at the wheels.
 
Depending on what h/c/i setup you go with, you will probably need bigger injectors. If you're going with a mild setup (GT-40's, mild cam etc. seeing less than 300rwhp) then you can get by with 19lb injectors and bumping the fuel pressure up with an afpr. However, this shortens the life of your injectors, and is not generally recommended. You're better off with some 24lb injectors. If you're gonna be making more than 300rwhp, then 30's might be the way to go, as 24lb's is only good for around 350fwhp (-300rwhp) at stock fuel pressure. You will need a tune pretty badly, although you can get by without it. Just do the work yourself, you'll save TONS of money, and although it might take a while (like I'm on my second week of my buildup), you'll be happy in the end.

EDIT: Donnie, I just saw your last post with the info about your setup you want. You should be fine with what you listed, MAF, 24's, fuel pump. I don't remember seeing an afpr in there, might wanna pick one up. You should be able to get by without a tune with that combo, although a tune WILL free up more HP, and possibly bring up your mpg a little. You might look into getting some gauges (fuel pressure, oil pressure, water temp. are the most common) to monitor how your engine is running.