With my current setup which would work better? I'm possibly going to end up with twins maybe sometime next year, all depends on certain variables. Would my current turbo handle mach 5's?

I hardly drive the truck so fully streetable really isn't too much of an issue, I've driven it maybe 500 miles since July, kind of just site sits in the garage

 

I think you could get away with the Mach 5 until you get twins

 

Try the 5's Just watch the money meter...

 

If you have a SB Special, you can go 6's.

 

my thoughts exactly i have 6's with a 62. you have a 64.

their were a couple sets in the classifieds.

 

Go with the 4's.... Without more air you will just add heat! The 4's are one of the best street use injectors around. I have run everyone of the F1 injectors from 2-8 and for my street truck 4's were the choice injector.

Doug

 

He said he is probably going to go with twins one day. Do you think 4's would be enough injector at that point, especially if he keeps his current charger for a secondary?

 

he could just turn his comp down.

 

I would say Mach 5's or go with the 6's if you plan on twins. I got 4.5's and my Special handles them no problem. With the Edge on level six it gets alittle warm but not bad. I have no problems with daily driving or towing with my current setup.

 

I have M5's & they are great with my 62, but I'd like to try some M4's. These 5's get hot above 3500rpm.

 

There is more to it than just turning down a box.... The spray pattern and atomization is just better suited for a street truck. Most guys use too large of an injector, the trick is balance. Heck I ran Bullydog 8's with a 62mm turbo on the street but it wasn't the best setup.

Heat kills things on these engines! Buy the 4's and if you do step up to twins look at 6's.

 

maybe so. i havent seen 1200* with just a smarty and 6's, basically the same egts as the 4's i had. i live on flat ground and dont tow.

cruising egts are a lil higher but not bad. i just got 19 and 20mpg on a 1000 mile trip driving 75-80mph.

 

Not a bash but if you went from 4's to 6's and didn't see any appreciable change in egt's (1200* max) your egt gauge is not working correctly or yoiu have another issue. There is quite the difference between these two injectors.

 

Personally, I think it's a waste of money to buy one set only to turn around and buy a different set later down the road when in fact the 6's are very streetable with the charger mentioned by the original poster. I've run 6+'s with the same charger and even towed with the setup. I towed another member's truck down to Tim Barber's place from NC.

I agree that 4's are a great injector but the 71mm turbine side of that charger keeps the heat in check with 6's. I saw 1650* in the 1/4 mile running 12.5's and I'm pretty sure my egt gauge is working.

 

Lets see you saw 1650* wanna bet on how many cracks your head has? I am not saying that you can't run larger injectors but it comes at a cost. To trade a set of 4's for 6's would only cost maybe a couple hundred bucks, cost of a new head is around $1800 and that doesn't include a HG or labor. Pistons also come into play and having to pull and engine bore hone and replace pistons is even costlier.

I have dynoed 4's and 6's back to back with a sps62 and there wasn't any real difference in HP. But the difference in heat was BIG (about 400*-500*) under WOT. So based on this one can run large injectors and get away with it but why?