92CamaroDE

I'm trying to decide what my next upgrade should be. My current setup is L31 350 with Promaxx vortec style heads, 46 mm bored TBI, lunati 20080660 cam with 1.6 rr., GMPP TBI intake, hooker headers into flow master y with 3" to rear, 323 posi 4th gen rear, ebl upgraded pcm. Car runs great, just feels like there's more in it. I was thinking maybe hot cam or different intake (or both). Any thoughts?

yaj15

iTrader: (3)

Are you still running a stock stall torque converter?

92CamaroDE

Thanks for the reply. I have a mild stall. 2600 or so. Trans is also upgraded with bigger servos, heavy duty clutches, shift kit. I saw on a previous post fast355 had mentioned the GMPP TBI intake was only good to 260 HP. I am thinking that may be causing a restriction for me. I did port out the intake to match my 46 mm throttle body. Thinking an edelbrock performer rpm with an adapter plate would be a better fit. Not sure though. I have also seen a post that suggested the victor jr single plane, but I am about positive that won't fit under my stock hood. My goal is low 13 with maybe 330-340 HP. Haven't made it to the track yet but my analyzer in the ebl software is showing around high 13.

RBob

iTrader: (1)

I'm running the Edelbrock Performer RPM on a 327 with TBI. Works well, I did cut the center divider down similar to what Edelbrock does on their air-gap intakes. Speaking of which, don't get an air-gap.

RBob.

92CamaroDE

Thanks for chiming in RBob. I appreciate your input. Do you think the Performer RPM will flow a lot better than the GMPP TBI? Also, what do you think about the cam I'm running. It has 213/219 duration @ 50. Lift seemed low at 447/471 so I went with 1.6 rr for 476/502 lift. Hot cam has more duration 218/228 @50 and has 490/490 lift with 1.5 rr. My heads won't support 525/525 with the 1.6 rr so I'd just keep it at 490/490. Think it would be worth swapping out or it what I have close enough to not really make a difference?

RBob

iTrader: (1)

Get a picture of each intake (GMPP & Edel), and reference the size difference in the runners and plenum.

RBob.

92CamaroDE

I see what you mean. I ordered the RPM Performer. Will see how it does. Any thoughts on the cam?

yaj15

iTrader: (3)

Thats a good stall. It will complement the other mods you have well. TPI dosen't need a lot of stall to work well.

92CamaroDE

I have installed the Performer RPM and it does feel stronger at the top end. I can shift a 6000 and it feels pretty good. I am doing a bit of tuning to try to get it as good as possible. Any opinions on the SA curve. It seems to have best vacuum at idle at 28 and I have 36 at 100 map. Seems like a lot of advance at idle but not knocks and it seems happy. Another issue I noticed is that DC is hitting 100% at 5000 rpm and gets to 127% at 6000. My wideband is reading 11.8 at 6000 though so not going lean. Any thoughts as to if I should make any changes.

Fast355

iTrader: (2)

My 350 Vortec head Express van likes about 30* @ 750 rpm at idle around 40 KPA, likes 32* total by 4,400 rpm. At the 100 KPA equivalent I run 16* @ 1,200, 22* @ 2,000, 26* @ 2,400-3,600 and jump up from 26*-32* over the 3,600-4,400 rpm range. 36* seems like a bit too much for a Vortec style chamber. I typically see the best results in the 30-34* range. 11.8 seems a bit rich too. I would shoot for more like 12.4-12.6:1.

92CamaroDE

Fast355 thanks for your input. I will back down the SA a bit. I have seen elsewhere 30 to 34 seems to work well for Vortec heads. I have been looking into my Duty Cycle issue. The more I read the more concerned I am getting. I reach 100% at 5000. I currently have the "cop car" injectors #327 in there. I have read they are either 65# or 68#. Not really sure which is correct. That's at 13 psi. I am running 17 psi now. Going to push it up to 23. That should help. I have a TPI fuel pump in it so I think it will be ok. Once I get that under control I can do some more learns and logs.

Ron U.S.M.C.

Delete......

92CamaroDE

So I have the Performer RPM intake installed and set my SA similar to Fast355's suggestions above. Also installed a remote adjustable FPR and set it to 27 psi. That put my DC at 90 at 6000 after tuning. Ran 13.4 at 102 at Cecil County yesterday. Only got 2 runs in so couldn't really test much to see if removing or adding SA would make a difference. I do have the Hooker 2055 header with the restriction in the ball joint so going to try to open that up to the carbon marks to get some more flow there. Other area I am working on is the air cleaner. My MAP at key on is 100 and drops to 97 at 6000. I have a modified stock air cleaner on it right now. May try a truck lid to give it a little more area in there. I would like to see 13.0 before I am done.

Fast355

iTrader: (2)

Are you still running the choke collar of death between the TBI and air cleaner? A powerbowl and base opened to the inlet size if the bowl will help alot if you are.

92CamaroDE

I had never heard of the power bowl. I looked it up. Will be ordering one and grafting it to my air cleaner. Thanks for the suggestion.

92CamaroDE

I wasn't able to use the power bowl. It just won't fit under my stock hood. I did go ahead and put an open air element with a K&N filter in it though. Did that along with opening up the collector outlet size on my headers. I have the Hooker 2055 headers with the ball flange. I measured about 1.9" before opening them up and now have 2.2". The car feels quicker by SOP. I did take it to the track Saturday and didn't have much luck. 1st run it didn't hook at all. 6.6 sixty foot (really not hooking) and it broke my trans mount when I shifted into 2nd. I wanted to get at least a 2nd run in so babied it out of the hole (2.0 sixty foot) and didn't wind it out in 1st. Ended up with another 13.4 at 102. I put a Poly trans mount in yesterday. I am confident it will do 13.2 with a proper launch and shifting at 6000 out of 1st. Still thinking about going with a Hot Cam 218/228 with 1.5rr instead of my Lunati 20080660 213/219 with 1.6rr. I need to keep my lift at .500 or less so cant really go much more than the Hot cam. Any thoughts as to if the cam change will pick up much?

Schurkey

Dyno or flow-tests to support this claim?

midias

Nice to see someone else running those heads. I run about 34 total timing with an XE274 cam. When I tune the carb properly in the spring I may play with it more but it seems to like that.

If you go to a higher lift cam keep an eye on the springs on mine I had a ton of valve spring dampers crack and break. I ended up getting some new PBM springs so far so good.