For my truck in the signature which F1 series would you guys recommend as an upgrade to my D1SC?

I currently see 16# of boost at my 6000 RPM shift points. I'm not looking to run any more peak boost, I'd like to see the boost sooner in the lower rpms.

I'm thinking F1D.

 

I don't think an f1 will change that characteristic. A slightly looser converter and a different cam would allow you to bleed off a little boost and fatten your mid range. To top that off you could then pulley down... more power all around.

 

While I don't condone it (due to potential blower damage), this is one of those rare circumstances that a wastegate and boost controller could be of great benefit.

Assuming for a minute that the waistgate/boost controller situation is out of the question:

Any of the new blowers (F1a-91, F1a-94, F1c-94, F1c-10.5 and F1x) wouldn't do well as they would be going backwards due to their peaky nature. F1c and F1r are out as they will due more harm than good limiting yourself on peak boost. So that would leave the -D and the -A. I've never worked on a car with the -D, but from what I have seen online, I agree with you and think it would be a worthwhile upgrade from the D1sc.

How fast are you currently spinning the D1sc at 6000 rpm? What bracket/belt/tensioner combo are you on?

 

I run the 99-03 bracket with stock tensioner. I think this has worked because I run a Reichard pulley and only shift at 6000 RPMs.

7.5/3.4 x 4.1 x 6000 = 54,265 rpm's

I know my D1SC could be spun quite a bit faster and run with a wastegate but I've run this blower for the last nine years and it's been great. I recently started thinking while it's still in great shape and worth some money I might upgrade to a new blower. That's when I started looking at the F1 series and particularly the F1D.

I was reading that the F1D has more low and mid range power than the F1A but with less top end hp. I wonder if the same can be said comparing the D1SC to the F1D at the same peak boost level.

 

Man I'm telling oh... going to a cam that will bleed off boost and let you work the d1 a little harder will make a night and day difference. You're also on a stock converter with a procharger... what do you expect? Get something that's even a hair looser along with the cam change and you'll love it.

Kurt made 14psi at 6800 rpm with his d1 on a heads and cam 6.0 with a 2800 converterspinnig it a hell of a lot faster than you are. The trucker cam is designed for great bottom end power with a tiny compressor. You need a cam that's designed for great bottom end power with a larger compressor.

 

If you're seeing 54k you still have nearly 20% more blower rpm to take advantage of.

My vote is for a 2800 and a cam that will not hit 15psi until around 6400 without a pulley swap. You'll be amazed what you pick up at the track and on the street.

 

Vortex - I agree man, there are things on my set up that I could change to make more power or perform better at the track. My set up is kind of a compromise between performance and what I consider fun and comfortable to drive on the street. Also the way I want my truck to look affects its performance, another compromise. A few examples are the truck has a lift kit, runs on 20 x 12's even at the track,stock converter and I still run a single 3 inch exhaust because I like the corsa with no drone.

So ultimately why I was contemplating an F1 D is because I would have a new blower and also the characteristics I read about them say that they have more low and mid range then F1A. I really don't know how it directly compares to my D1SC. It's like trading in a car while it's still worth something and getting a better newer model that performs a little better in certain areas.

Also this converter does flash to around 2700 but l know there are other characteristics to a converter that matter too.
What cam specs would you run instead of my trucker cam?

 

Yea a 2800 would probably flash about 3400 in your truck. Maybe higher.

I'd probably go to something like a 224/234 on a 112+4. It would idle more aggressively by a lot, but with a good tune it would have plenty of manners. This cam has 5° of overlap while the trucker shuts the exhaust valve relatively early and has -10° of overlap. Who doesn't love a little chop anyway?? Believe it or not the slightly looser converter would also help with its driving manners. The new cam has an intake close that's only 2° later despite its increased duration of 8°. It would make a TON more mid range without giving up much of anything down low because of that. Even locked on the highway it would have plenty of grunt. It would also bleed off enough boost to let you rev past 6k and let that blower continue to work where it's happy.

I most definitely understand wanting to keep your 3" corsa to avoid all drone. What headers do you have? I'd not be surprised if you're right on the edge of making a fairly large emount of backpressure in your exhaust if you aren't there already. Id say it's worth measuring that. If you are you would be amazed how much power you could uncork with a couple of cut outs before the corsa system. Seeing as it's a lifted truck I'd just go with standard bolt on covers to make sure you never experience any leaks.

I also understanding the whole trade in while it's still worth something. I don't think that's a bad idea by any means. Hell bigger is almost always better . I just don't think you will see the gains you expect. Hell the mods I'm talking about would love the bigger blower even more. Maybe I can motivate you to do it all.

 

I think I'm gonna retract or restate my previous posts after this new info has been posted and I'm gonna side with vortec350ss and say that you still have a ton to gain in sticking with what you have.

A cam change and pulley change could be amazingly beneficial here (I didn't realize you are barely spinning the d1sc).

Either way you decide to go, an upgrade and modifications are going to be needed to your drive system including tensioner, rib count, bracket stiffness blah blah blah.

 

spin the blower harder and do a converter

i spun my old D1 to 65k