s3gulit

iTrader: (2)

hey guys n gals,

So i got my vinci "062" cam in and the truck is f*ckin amazing on the stock tune...i'm really surprised the stock tune is handling it so well. Only problems i'm having is it stalls out after it gets warmed up since its still un-tuned.

I was gonna go with a bunch of guys off gmfs and get my truck tuned at zippy's in michigan.

here's where i'd like some input/advice/knowledge.

cam is a 210/218, .551/.551 112lsa cam...

I've been told i need larger injectors because they'd be running almost open all the time at 6000rpm. Another guy i talked to says the stock (24lb?) injectors are fine and that i shouldn't have any problems.


I really don't know how to calculate the right injector size, and i really need a tune, but i don't want to risk an injector failing on the dyno and then be stuck 4hrs away in michigan.


Could anybody give me some hands on or actual info on whether or not the stock injectors would work, and if not what would?


Thanks,
Dave

hirdlej

iTrader: (31)

24lb injectors will work terrific for you. The real question is, does your truck have them? I know 99's were only 19lb injectors, but I'm not sure when GM started putting larger injectors in. I just sold a set of 24lb injectors for $40 shipped, you should be able to find an equally good deal in the classifieds. Ask someone selling some 24 lb'ers and have them read the part number off the injector for you. Then look at one of yours and compare. You'll know if you have them or not.

Stoichiometric

iTrader: (10)

Dave,
If your injector duty cycle is more than 85% you are getting close to needing larger injectors. This will not likely cause a failure. Many run their injectors over 100% without harm to the injector. The tuner will be able to tell you your IDC. Newer trucks have 24lb/hr injectors and the older trucks had 19lb/hr, not sure of the cutoff year though.

kbracing96

iTrader: (26)

You should be fine with that cam and only spining 6000 on the 4.8 with the stock injectors.

s3gulit

iTrader: (2)

thanks guys...i havent taken it above 4000 since a buddy told me that so i was kinda scared to drive the truck much really, lol. only put 200 miles on it in the past two weeks and just drove the duramax around.

Anyone have the numbers for them by chance just so i could double check?

BTW: i LOVE taking my truck to the moon (5400rpm stock limiter) minute it hits 4500rpm it just breaks em loose on regular pavement

xlcooplx

iTrader: (26)

Dave, FWIW, I've got a 212/218 as well...my IDC is 97% on my 5.3 spinning it to 6100 RPMs. Thats on the stock 24lbs. I'm upgrading to 42lb 8.1 marines.

s3gulit

iTrader: (2)

well it rarely see's 6K unless im at the strip or tryin to pull some donuts...i wouldn't think the two or three times a month im at 6K it would hurt it THAT much.

There anyway you could get the #'s for me off them and i could reference mine to see if their the same? I already spent damn near $1000 for the swap and figured my injectors would be fine.


If i get a tune, will i have to re-tune it later for the larger injectors?

Stoichiometric

iTrader: (10)

Yes, you will need to change one table for the larger injectors. When you get tuned you will make a fair amount more power if you raise the rev limiter. I have my limiter at 6600.
Do you have any video floating around of your truck, it sounds like it runs good!

s3gulit

iTrader: (2)

not yet...my camera phone's video option pretty much blows. Im waiting to get it where its still and hopefully it'll sound better.

silver-mod-o

iTrader: (15)

you'll be fine on stock injectors... I'm running stock injectors with a 5.3 224/227 cam, full bolt ons... the IDC has gotten in the 120% range a few times but they are still running fine even with 120+ K miles on them...