Well, i finally have some comparison results between manifolds since it's so hard to find out there and know some will be interested in looking. I was very impressed after hearing most say you wouldn't see much of a difference. I always believe the minimal results to be true on a lot of N/A setups that didn't run in the big power range, but figured it would be a different story under boost. This was a straight out swap alone with no other changes to my setup pre and post swap. Just the manifold change only! The manifold is a ported Victor EFI on my Vortech YSi 383 9.0:1cr LT1 at around 14psi. Ported LT1 heads with 2.00/1.56 valves, 218/224 115lsa Comp cam, 58mm TB, 1 3/4" Kooks LT's with open cut outs at the time of the pulls. Used TunerCat for tuning and ran A/F's at around 11.5:1 for both runs, although my LT1 manifold tune was a little lean in the lower rpms. Weather temp was about 12deg cooler after but humidity and pressure was basically the same. The old manifold was a ported LT1 setup. Look at the results at 5500rpm. Started getting belt slip at about 5600rpm that i actually saw in my map readings. You can see it in the dyno chart also. I'm happy with the results....



I don't know about anybody else, but i'd say on a setup like mine, the swap is definitly worth it... If it wasn't for the belt slip, i think i would have made well north of 750hp and 700tq.

Ken R.

 

Nice Ken! Are you running the 58mm TB? If so what elbow are you using?

Chas

 

nice graph, i like how it shows where the ported lt1, with shorter runners has more potential in the lower rpm range, which would benefit a street car more, but for something like an all out drag setup, or someone who really drives the crap out of thier car would obviously benefit more from the vic jr. setup. you can clearly see at about 4k rpm the crossover is quite drastic, abd befor that point there isnt a whole lot to be gained from keeping the ported lt1 manifold unless you dont run over 4-5k rpm often. great comparison chart. Ive got a stock lt1 manifold on my setup now, and im porting another ATM. Wonder how much there is to gain?

 

wow thanks, now i gotta change it haha, im gonna get a super vic , lotsa room on a third gen haha, prob go with an acufab 2000CFM 4150 TB

Jay

 

I think one of the big reasons the power was still better in the lower rpms was because the fuel mixture was leaner on my tune when using the LT1 manifold. I think if i was running it where i'm running it now, the power would probably be close to the same down low. As far as the elbow, i'm using one made by 860performance from Nitro Daves i believe. Its made to work under my SS hood and takes a stock type TB. I'm using a BBK 58mm. I'll try and post before and after pics when i have time. Overall, i'm very happy with the swap and can't wait to see what it will do on the track. I'm really curious because from a mph perspective, previous boost to current boost pulls, it picked up 16mph. On the old manifold under boost only, it did 124 on the dyno. With the Vic, it did 140 and i didn't even spray it. It only did 133 with the LT1 manifold on the dyno with the spray, then went out to the track that weekend and ran the same mph. Too bad our track is closed for the winter now.

Ken R.

 

any pictures of the set up?

 

nice!

can you post a link to the full size graph?

 

Is this a little better? Its full screen when i preview the post but shrinks when i save it.

Ken R.

 

Here's some before and after pics.







Ken R.

 

do you have any pics of the vic jr intake off the car?

 

i have searched for this intake and cant find it anywhere

 

I never took any pics before i put it on. The Victor EFI is available anywhere you can buy a manifold. Summit, Jegs etc, but it has to be converted to use it on an LT1. The bolt holes don't line up and you have to shave off the water port and weld up the distributor hole. Have you been trying to find one thats ready to bolt on?

Ken R.

 

That's F'n nice ! more pics, please....

 

Great results. I really didn't expect that much. We had been discussing building a sheet metal one, maybe I will pursue it now.

 

Love the way the setup looks.