Heads And Intake Question

[chpspecial]

The stock LY6 Injectors are ~30lbs/hour

[BlueAKSSS]

The stock LY6 Injectors are ~30lbs/hour

 

[zachm89]

Okay, that's not too bad I suppose. I might look into getting some 42# injectors as well then. Would it be worth it to have the intake and throttle body ported as well?

[BlueAKSSS]

Okay, that's not too bad I suppose. I might look into getting some 42# injectors as well then. Would it be worth it to have the intake and throttle body ported as well?

 

Well someone asked that question over on performance trucks about the stock LS3 intake and they basically said there isn't much of a gain out of porting that manifold but I'm sure the truck manifold is a different story.

[zachm89]

Well I'm buying the intake and throttle body tomorrow, it should be in sometime later this week. I'm going to be on the lookout for some 44# injectors but if not I'll just use the stock 30 pounders. I'm thinking I'll get the intake and throttle body ported as a birthday/Christmas present to myself while I'm still on the lookout for some L92 heads. As suggested by Danny (retired99) I'm going to have a valve job done on those when I do find a set. I'm hoping to have this whole swap along with the cam done sometime around February if my budget permits. Any idea of what I can expect for gains with my current mods and a cam similar to probably a 222/224 on a 112? I know it's hard to say but a ballpark estimate would be nice. Also, does anyone know of someone who does good port work on intakes and throttle bodies?

[BlueAKSSS]

What has been found by myself and many others is that it is very hard to make really big power with L92 as they don't really respond all that well to camshafts over 230 duration. I frequently see them with cams bigger than that, but you'll find that they don't make much of a gain over the same setup with a small cam. For anyone considering running an L92/LS3 port cylinder head I commonly recomend a 6-8 degree split for a naturally aspirated setup and around a 22x/23x duration range. As a comparison stand point an unported 317 cylinder head with a 228/230 cam with a long tube header and a truck intake will make around 390RWHP. The same LQ9 with an unported L92 cylinder head and a 223/231 cam with a long tube header and a truck intake will make around 420RWHP or so. The L92 setup will also have a smoother idle with more vacuum.

 

The short of it basicly is that if you want great drivability and 400-450RWHP, it's hard to beat an L92 port cylinder head with a small cam.

 

I think that sums up your cam choice nicely!

[misterp]

Injectors - since the ones you are buying are so new, you might investigate how much it would be to have them modified (drilled-out) to give the flow you are after.

 

P&P Throttle Body =

 

Mr. P.

[zachm89]

Seems like that would be a hastle trying to find a place to do that that I could trust to do it. I'm buying Brians 44# injectors, figured it would just be easier and less time consuming. I might be able to pawn off the 30# ones separate once everything is said and done. So you think the p&p throttle body is a good idea? What about the intake manifold...? I figure there's probably some power being left on the table with the stock ly6 truck manifold, especially if I'm going to get the heads worked a little bit as well. I'm going to call Richard at wcch today and see what his thoughts are on everything.

[misterp]

Seems like that would be a hastle trying to find a place to do that that I could trust to do it. I'm buying Brians 44# injectors, figured it would just be easier and less time consuming. I might be able to pawn off the 30# ones separate once everything is said and done. So you think the p&p throttle body is a good idea? What about the intake manifold...? I figure there's probably some power being left on the table with the stock ly6 truck manifold, especially if I'm going to get the heads worked a little bit as well. I'm going to call Richard at wcch today and see what his thoughts are on everything.

P&P TB does not show much in peak HP gains, but it does 'drive' better, you get a little peppier throttle response off idle so that's more 'torque under the curve' and would be an improvement you feel every day you drive the truck. Porting the truck intakes, I don't know much about other than (a year ago) persons that were playing with porting factory intakes basically had to cut them in half to open them up, then discovered there wasn't a whole lot to work with in the moldings, then had to epoxy them back together. Best I heard was that there might be a little to gain in enlarging the TB mount area and smoothing those first two inches into the manifold. But really I am talking out my azz here, that's just what I heard. The guys cutting apart manifolds were doing "specialized modifications" like inserting nitrous spraybars inside the manifold to go street racing, so porting wasn't exactly their main focus of effort, if you get what I mean! But they did figure what glue you had to use to put it back together, I forget what to use now...

 

Mr. P.

[zachm89]

Bahahaha okay then. Well the reason I'm thinking about it is because there is a sponsor on ls1tech that does intake and tb porting and they claim some pretty damn good gains over stock manifold, somewhere in the 25-35 hp and tq range....so if that is true, which I don't see them being a supporting vendor if they were full of crap, I figure it's a good investment. So I guess I'll keep my fingers crossed on that one.

[misterp]

Bahahaha okay then. Well the reason I'm thinking about it is because there is a sponsor on ls1tech that does intake and tb porting and they claim some pretty damn good gains over stock manifold, somewhere in the 25-35 hp and tq range....so if that is true, which I don't see them being a supporting vendor if they were full of crap, I figure it's a good investment. So I guess I'll keep my fingers crossed on that one.

Ask questions and investigate! If the gains are real and the price is right then it may be a real alternative for you.

 

Mr. P.

[05VHO]

I'd look more into milling .030 vs porting. The guys on ls1gto have had a lot of success with this.

[zachm89]

im not going to have the heads milled because from what ive read there isnt much room for milling on the l92 heads. im talking mainly about the stock ly6 truck intake...surely there is some hidden power in there somewhere from a good port job.

[05VHO]

I wouldn't guess more than 7-10 rwhp. I sure it would have a lot better throttle response though.

[detjoe]

fuel injector connection =FIC is a good injector place for buying new or having them modified...I hate to say go 60's, but I will

go 60's

 

I left my heads as cast with the OE value stuff and better springs...stock TB, stock truck intake,...I think you will be a low 13 truck with them as is.