dkeets

iTrader: (1)

Ok so I built a LQ 408 for my TA a couple years ago. It was meant to be a street car with nitrous for racing. I have PRC 247 66cc heads, 244/248 .612 .615 114 cam, CR is 10.7:1. NA she made 480 and on 150 shot she made 680. As of late I have been tossing around the thought of supercharging my motor to have a little more punch on the street and still spray for the track on top of the boost to chase time slips. So with my CR where it's at I know I can't boost the crap out of it running 93 octane. But would low boost be able to net me around 680 like the 150 shot does? I'm thinking 6-10 psi. Or would 6-10 psi even be effective on a 408? Any insight would be great thanks in advance.

05GTO6.0

Yes. If youre that concerned about knock with 93 octane you could always swap some different heads in to lower the CR, but 10.7 could easily handle 14lb with some meth injection, if you stayed at 6-10 psi no meth needed, and since psi means more the larger the engine you have, 408 just makes 10psi on your motor make a lot more power than 10psi on a 364. Imo you could push a forged LQ 408 to 850 wheel and still be reliable, would recommend a tvs2300 at 6psi should hit your 680 and have 750 or 850 just a pully swap away

dkeets

iTrader: (1)

05GTO6.0 Thanks for your input. I'm really hoping to keep from changing heads or cam, so even being able to achieve 680 on 93 would be great. I would also like to avoid meth if possible. I'm just not sure how tuning for meth boost and nitrous would workout??? I'm sure it can be done I'm just skeptical about being dependent on meth also.

I've always seen a better overall performance in centrifugal blowers so that's what I really had in mind. Any reason for your suggestion on a roots style blower for my setup?

Bob@BruteSpeed

iTrader: (16)

10 psi of boost from a ProCharger could get you an extra 200+ rwhp with your combination, it would make a significant difference. Bob

05GTO6.0

Personally, i have no idea why anybody pays for centrifugal superchargers, since turbochargers exist. A turbo would reach your desired boost much earlier in the rpm range than a centri, and have no parasitic losses. I recommended a roots blower because those give you what turbos cant, low end torque. You would be right that centris usually out preform roots, but at the sacrifice of the torque curve of a roots. either way FI will give you absolutely insane amounts of power, so if you have a personal preference for centrifugal sc's then go ahead, nothing will dissappoint you!

As for the meth injection, I think your nos would accomplish the same goal. Meth injec exists to lower IAT's to reduce knock on low octane fuel, but since nitrous also lowers IAT's it should work fine if properly configured. If you stay below 12 psi i doubt you'll have any knock issues, but if you do turning it down to around 9-10 would completely solve them. If you could configure it, i think 8-10 psi without nos could be stepped up with a boost controller to 15 with the spray active, but that might be too complicated to set up haha.

As for the cam, the 114 seems a bit low for boost but it should work just fine. You would benefit from a blower cam but its hardly imperative. Good luck on your build!

Bob@BruteSpeed

iTrader: (16)

A lot of guys sell their blower kits and go turbo, then get tired of having problems with their turbo kits, then order another ProCharger from me. This has happened more times than I can count. I'm not saying everyone with a turbo experiences constant problems, but it sure seems like a lot of them do. Bob

dkeets

iTrader: (1)

Bob & 05GTO6.0 Thanks again for your insight.

What size supercharger would you recommend?

05GTO6.0

if youre wanting roots, its a 408 so i would recommend the tvs 2300 like i mentioned earlier. the 1900 would just be too small for that much displacement. For centrifugal, its honestly out of my scope of knowledge so ill let a procharger distributer answer that question

Hi-Po

iTrader: (4)

From what I have seen, the Prochargers love a little compression. I wouldn't hesitate to throw an F1A at it, pully it to 10 lbs with good fuel, a bunch of meth and have fun.

Coming from a turbo guy who has dealt with Bob in the past, top notch dude!

dkeets

iTrader: (1)

Would a F1A be able to pulley to 10psi and at 10psi would the F1A be efficient?

Hi-Po

iTrader: (4)

You might end up with a dinner plate for a pulley, but with a ton of belt wrap! Maybe a D1SC is the way to go, I'm sure Mr. Bob can point you in the right direction either way.

Bob@BruteSpeed

iTrader: (16)

You're welcome. You could either go with a D-1SC or an F-1A. The D-1SC will max out around 750 to 800 rwhp, and will easily handle your current goals. An F-1A wouldn't have to work as hard, and would give you options down the road should you desire more power. Bob

Bob@BruteSpeed

iTrader: (16)

Thanks, I appreciate it! Bob

Bob@BruteSpeed

iTrader: (16)

Yes, a 5.00 pulley would probably get you into the 10 psi range. I've seen good results with the F-1A in this lower boost range, it works very well. Bob