I know there are several threads tlaking about the Fast vs the Vic Jr and I need to hear first hand testimonials from people who have used the VIC JR/ 4150 style TB in aggressive H/C LS1s.

I have tried calling a few well know tuners and even they dont seem to have a lot of personal experience with the Vic Jr. Everyone seems to use the fast. I even emailed, PM'd, and called Dez Racing just because I respect Slowhawk's opinion on making a fast car, but I cant get a hold of the guy, and they are the shop I'de like to have work on my car based off the positive comments made about their shop here on the board, and they're about 30 mins from me.

I am planning on using some cnc ported Ls6 heads from patriot/TSP paired with DemonicBird00's custom cam (he had great results without flycutting on stock heads) look here.

http://www.cardomain.com/ride/574623

I'll be spinning my motor to 7200rpm as well. This is going into a stripped 2500lb Ls1/t5 rx7 running 4.10s with a 100-150 shot. I am shooting for 140mph traps. Btw I have no issue putting a hole in my hood.

I am looking for some results dynos/track results with H/C Ls1s running the vic Jr/ 4150 TB. I already know the Fast is a safe bet but it has been said before on here that the Fast starts backing up after about 280cfm and the vic flows a little better.. that may help my top end with a huge cam like the one I'm looking at, with the heads I'm looking at. A lot of the people on here running the Vic JR seem to be running the elbow which I believe adds to the plenum volume and may be part of the reason most people report low end power loss with the Vic Jr. I will not be running an elbow.

Also most of the people on here are looking for midrange power. My rx7 is a race/weekend car, is much lighter than an F body, and already has 4.10 gears so I am not that worried about losing a little bit of Tq to gain some more HP.

Any info from knowledgable sources would really be great. I am looking to start purchasing the parts to start my engine build but I am not finding any answers.

Thanks,
Josh

 

Sorry I posted this in internal. If one of the mods could move it to External Gen III that might help.

Thanks

 

anyone?

 

What throttle body are you planning on using without the elbow?

 

A 4150 style 4bbl TB for EFI.

Like these

http://www.straightline-perf.com/cat...roduct-31.html

http://www.compperformancegroupstore...tegory_Code=TB

http://www.youngsperformance.com/ind...opic=induction

http://news.hspn.com/articles/937/1/...EFI/Page1.html

(btw does anyone know the benefits of having the fuel injectors up by the TB, its wilson and they make good stuff but I cant figure out why this would be better)

 

I'm very interested in the results of this. Please share it with us.

 

+1 me too..

I just need to get some info from more experienced folks before I throw my money down on this setup

Still waiting to get a call/pm/e-mail from Dez racing. Well at least I know they must be good if they are this busy, but if I knew of another good shop in the area... I'de rather get my work done somewhere where they probably appreciated the added business a little more.

 

I have been interested in either the GM or Victor Jr manifold with that type of throttle body on it. But I have not been able to find out much about that application from anyone. Does Dez have experience with this type of setup?

 

With the appropriate cam, big stall, big gear, drag application the Vic ported should do well on an all motor 346 application. there are good results out there. With spray theres no doubt that the vic will distribute fuel/nitrous better than the Fast. The big question remains is the Vic maxed out better than a Fast maxed out on motor? Everyone knows that its not cheap to be playing around with intakes on these motors. It would be pretty disappointing to have a good working Fast 90 combo then buy a vic, port it, buy a 4bbl tb, cable bracket, throttle cable, cut up your cowl and hood, and lose your ability to ram in air going down the track only to see similar if not worse results. I dont see anybody having a definitive answer to that question anytime soon.

I'll do it though if ya'll want to start sending some donations

 

I thought about doing this too for a cam only set-up, but then changed my mind. Maybe if I get some good heads

 

I have a t56, but then again if I lose some power in the bottom end it would probably be a good thing seeing as I'll be running only a 245 width drag radial out back and a rear end, only a little bit stronger than a 10bolt.

I believe slowhawk / Dez racing does have experience with these intakes.

 

I am more interested in a non-race car application..I would think that under full throttle the VJ intake 4150 TB would be much better flowing .. but how it would perform in a street driven application and what kind of drivability issues is my concern...It sure looks a lot kooler than the fast intake/throttle body system.

 

Well the great thing about the 4bbls are that they flow a ton Usually 1200+ cfm when you go wide open throttle, but most of the time they only use 2 of the 4 butterfly valves.. so part throttle response and proper idle is usually well maintained.

 

Those are my thoughts too but just want to hear from someone who has actusally used this configuration with success and what their gains were and what are the drawbacks..

 

Well some people on here will tell you that an aluminum intake suffers from heatsoak compared to the plastic composit intakes. In an Fbody running this intake without an elboow would require serious modifications. Corvettes, have to put a hole in their hood. A lot of people also say the vic jr could be better on the top end than a Fast but most feel the fast produces more area under the curve. These are some of the drawbacks.. that keep most people on this board from using it.

Positives are that its cheaper, has a more nostalgic look, some people say it flows better than the Fast in the top end, and has more potential if you port it, than a ported fast. A lot of guys running FI use it because the fast is not as reliable at high boost. Also guy running huge shots of nitrous also stay away from the fast because of the potential of a nitrous backfire..

I just need some real results.. anyone know of another board where the vic jr is more widely used?

 

I have read all of that conjecture before ... I am looking for real world experience not someones opinion..from someone running it now who has some data on the application ..

 

https://ls1tech.com/forums/dynamometer-results-comparisons/836325-all-bore-383ci-vic-jr-numbers.html

tell me a fast 90 setup would've done that. haha.

 

I had forgotten about that. Thanks for reminding me. I am close to just going out on my own and trying a setup.


I think the vic JR will work with whatever heads I pick, just fine, its picking the right cam, I'm worried about.

 

Great numbers for a 383 but it is a race car not something you could drive alot on the street...

 

As he said he could drive it on the street.. and what I'm looking to do, most people would call a race setup. I work for a dealerhsip so I wont have a problem with state inspection. Otherwise my car will only be taken out on sunny days, and to the track.

As long as it runs on 93 its all good for me. I am planning on spinnin my motor to 7k or 7200rpm.. The only thing that looks a little extreme is the compression hes running.

I will have to PM him about that cam though, obviously its working with his combo



Any more input would be great