3400 Impala Engine Mods

[IanSzgatti]

If you go to a larger injector, and don't adjust the duty cycle, then yes it will run poopy. If you can adjust the duty cycle to make it shorter for a larger injector, then great. If you don't, then if you have radical mods it might not starve it at WOT, but at idle and everywhere else it will run way rich.

thats just the thing... your still getting more air in through a bigger tb (9% angle with a 62mm is more than 9% angle with a 52mm), and even at idle, your 02 sensor will know whats rich and whats lean...

if the duty cycle of the injectors in question are the same, then everything should be fine... i cant see a rich condition occuring... i can see the 02 sensors making the PCM cut back pulse width a little more than normal...

i only argue issac because i dont have a final and total understanding... it's mostly because I trust facts and figures rather than only what somebody says... no offence eh...

[IanSzgatti]

Hey Ian. I'm in Hamilton and I have ordered lots of things from Ben for my 3500 swapped Beretta.

Service is excellant, and while shipping can be a little pricey, I have never had a problem with Ben at all.

hamilton eh? well we'll meet eventually... im originally from hamilton. I chose this town to work in because it's cool to go around town and see all the peoples cars you've worked on... it's still got that small town feel where people know you and you dont feel like a number...
anyways, i'd like to see what you've done some time.

[asylummotorsports]

Hey Ian. I'm in Hamilton and I have ordered lots of things from Ben for my 3500 swapped Beretta.

Service is excellant, and while shipping can be a little pricey, I have never had a problem with Ben at all.

[IsaacHayes]

If you go to a larger injector, and don't adjust the duty cycle, then yes it will run poopy. If you can adjust the duty cycle to make it shorter for a larger injector, then great. If you don't, then if you have radical mods it might not starve it at WOT, but at idle and everywhere else it will run way rich.

[IanSzgatti]

I thought 99 3100 was 19# injectors.

i suppose you could be right.. a short pencil is better than a long memory, the latter of which I do not have.

I couldnt wrap my head around it though... from THIS site I learned that you'd need a tune for the larger injectors, yet im being told that it's the duty cycle thats important... that it's the same duty cycle, so it will flow more and be useable.

Since the 02 is detecting all the extra from the larger heads, intakes, etc, it will be able to keep the mixture correct.
Anyways, thats why im not even concidering tuning with only heads and intakes and some exhaust work. If those 3400 heads flow so nice I think i'll be happy with those.

thats why im suggesting to this guy that intakes and exaust would probably make him well enough happy... especially 3500 stuff and that big ole' 62mm. i've wanted one of those for over a year... but up in canada i cant get things shipped to easy.. it becomes really expensive

[SappySE107]

I thought 99 3100 was 19# injectors.

[IanSzgatti]

I work with a mechanic thats been in the bizz almost 30 years. He's been in dealerships doing driveability, worked with Snap-On training technicians to use diagnostic equipment, etc.
I told him about fooling aorund with my 3100. I said,
"I added 3400 intakes an TB to my small valve small port 99 3100 but I want to add the 3400 heads.. will that operate outside the range of the engines sensors?"

He told me no. He said that I should use the newer style injectors as well. My next question was about the injectors... I was curious to know if they'd work by wiring them in, and I told him they are 21 pound injectors compared to the 15 lbs injectors in it now. he told me not to worry about the injector lbs for my application... that it was the duty cycle that was important.

I think if you do the LIM and the upper... add a nice big TB, free up your exhaust manifolds... you'll be quite happy. who knows... I drive a Malibu, which is lighter than the Impala.

[HotSauce6226]

I plan on it. If money permits..

[johnnymossville]

Ben sells the best parts for the 60* v6 engine, no others compare. The performance parts that I have came from him, everything else has a GM part # on it. My hybrid is awesome but it doubled the fun when I put a set of S&S headers on it. To create more HP you need to put more air in the engine which means you have to get more air out. People with the best numbers (HP/Torque) run headers. Oh yea, one other thing, "BUY YOUR PARTS FROM BEN AT WOT-TECH.

[RedBird]

yeah, if you're going to have a shop do it look to spend probably just shy of a grand to put on heads and intakes. a LIM job would cost you about 600ish, depending on where you go, plus removing the heads and exh. mani's and installing the new ones on top of that. headers will cost you about 500 more plus however much they'd charge you to install them while it's all apart.

[Alxsmt]

for the top end that would be your best choice IMO. there ive heard s&s headers give you a pretty good gain too. i kinda did all mine at once so i couldnt tell ya lol

me and a buddy did all my work, i would imagine any decent mechanics shop around could do it. just gotta make sure you tell them what your doing/parts you have and what gaskets to use (if you dont have them)

[HotSauce6226]

Where did most of you guys get your stuff installed? Can a good shop do this?

[HotSauce6226]

I have a tuned PCM now, but i guess it needs a new one if i decide to go this route. I just want to make sure I get the best bang for my buck. Thanks guys

I love this idea
Best option would be a 3500 topend swap and have your 3400 UIM ported to match a 3500 LIM for an easy install. Wot can port you an upper to match a 3500 lower. This way you won't have the ugly 3500 UIM. Wot-tech Stage 3 cam and a 62mm Tb. Maybe a 65mm but i'm not sure you would benefit much from it.

[Alxsmt]

what about tunning? im not sure how much you can get away with with out a tune. i know on my car it ran slower that a stock 3400 with out a tune, but that was with 2.8 ecu/injectors also. just something else to think about

i also recomend wot-tech, ben has good products and does great work

[HotSauce6226]

If i could get away with $2500 tops. I have no clue what HP im putting out now, or what id be putting out then. Plus to have someone help me or install it all together is where it will get pricey. Id hate to have to drive 4 hours to get my car worked on but.....