I am looking to build a supercharged 391, and I can't decide which to use. I have read some people having issues with using a mini ram on a forced induction set up and I am looking for some input from someone with first hand experience.

 

have an LT4 manifold machined to accept a distributor and the bolt pattern fixed for gen 1 heads and the water passeges setup for gen 1 as well and you have just made a great manifold for your gen 1 engine for ALOT less then all the other setups.. you can find fuel rails and everything else you need very reasonably off ebay or the for sale section.. this is what I would do in the same situation just for the proven performance they have!

Chris

 

EFI single plane...
-Jeb

 

I have a super ram, and a mini ram. I have not used either with my supercharger. I have used my supercharger on my 96 LT4. I like the previous post idea of using the LT4 manifold which is verry similer to the mini ram but has all smog connections. the mini ram & LT4 manifolds improve higher RPM power. The super ram improves low & mid range power. It improves high RPM power as well if you have high flow heads & cam. The super ram can complement the supercharger, reduce lag & give more power at the RPM we use on the street. I'm considering doing this with my LT4 as I am replacing the engine. Hope this helps

 

Import92,
I have run long tubes, the superram, and currently run the MRII. With a blower, the SR makes too much torque in a strong package which precludes decent use of the vehicle.

I installed the MRII to reduce bottom end torque, and found that the MR makes plenty down low on it's own. The MR does have its fault at higher RPMs on a FI motor in the distribution area. I hear others who are in the 525-550RWHP range that are not facing these issues, but I have been fighting this from the beginning of my combo. Due to this, I have now decided to move to the SP intake.

The SP intake can be viewed on this forum under my post.

Best of luck in your decision.

TPI,
Why would you replace a nice LT4 intake with the SR design. It seems like you would be going backwards on power and also asking for much more installation fun.

Aaron

 

MY LT4 With or with out the supercharger doesn't produce much tork below 3000 RPM. THe supercharger doesn't spool up untill then and I have to lift throttle due to wheel spin when it kickes in above 3000 Rpm. On the track, or drag racing its no problem. Just keep the RPM up. On the street I would like more low end. I read a mag article with dyno tests that show that the SR will increase torke at all RPM's with hot cam LT4 heads and headers. My thought was that I have LT4 heads rockers and hotter cam than a LT1 that was used in the article. I could stroke the engine for more low end, but muchmore involved than an intake swap. The supercharger should more than make up for my stock LT4 cam vs the LT4 Hot cam. Obviously this is theoreticle. Can you be more spacific about your experience with the SR, and what mods were on your engine. Thanks for info.

 

I was very happy with the SR on a 350 with a P600B and then later a D1. This motor had AFR195s, TPIS 228/228HR12, 11.2:1 scr and went to 570ish RWHP. The intake took the car to many very low 11s, but never into the 10s due to some traction issues (C beam was loose for ~14 months which netted 60' times in the 2.7 - 3.3 sec range; UGLY).

I was running the SR on my 408 with a D1 and had way to much low end torque. I was running a SR cam that was 248/254 @ 0.050 with just shy of 0.670" lift. I had ran to the 10.40 range with this set-up, but had difficulties off the line (60' in the 1.85 - 2.4 sec range).

The thought process was to reduce the torque by going to a MRII. Surprise! The massively ported, chopped, welded, epoxied MRII and the SR cam still pulled easily from 1500 RPM. There is no drama even cruising across a parking lot in 2nd gear at 1100 RPM (no jerking, no drama). This was totally unexpected! I am into a couple of pounds of boost by 3K, and all spent by ~6400 (may have more power, but the MIP is met at 6650 RPM). If you remove the blower ducting and run NA, the car will just light the tires (315 DRs) with a blip of the throttle, no clutch below 2K.

I have had the air distribution issues since this motor first used the D1R. With the MRII, coming off the dyno, the 1/2 plugs would run very rich, 3/4 would be slightly dark, 5/6 would be great, and 7/8 would look a bit lean. This had me so concerned that I would not pull past ~6K on the dyno. I have talked to TPIS and others about this issue, but their comment is that this intake was designed for 400 - 550 FWHP motors. I have been steadily pushing the motor harder and further and decided it is time to do something about the intake issue, so C4SP is the direction I am proceeding.

Aaron

 

TPI,

just out of curiousity.. what rear gears are you running? perhaps if you are still in the stock ratio, upping to something higher could help your low rpm pull for around town.. I know when i went to 4.10 gears in my hot cammed 350, it had massive amount of low rpm grunt hell from 1500rpm in 4th gear she was still lethal she made so much usable torque.

what cam are you running? cam can have a lot to do with your power band.. perhaps changing the advance of the cam with an adjustable timing set... this can bring the torque curve down a little lower.. or possible some more timing down low.. a loss of torque at lower RPM ranges can be attributed to lack of advance.. you could have more torque left in her if your tune isn't nailed down.. give us some more information!

Chris

 

One of these sure would be cool. Has anyone managed ITB in a c4?
http://www.kinsler.com/i_manifolds.htm Since it's 3 piece I bet is would be a cakewalk to modify for LTx bolt patterns.

 

I was running stock LT4 with a procharger. After two defective FMU's it developed low compression in two nonadjacent cylenders. I have pulled the motor, and I am considering buying a 383 stroker/blower(9.0:1 compression) forged short block which would cost about the same as a stock rebuild. I want to run the motor with an ECM rather than using a FMU. Any suggestions apreciated.