1993 c4 6spd

Thanks to Bob at Brute speed for hooking me up with a good deal on a d1-sc

i had my p600b maxed out and wanted a little
more (i was getting 12.5-13psi boost at 6000-6500 rpm on a blowerworks 2.625” pulley and 8 rib dedicated drive setup) and gates RPM belt.

I sent the p600b to procharger to get it checked out, seals replaced, etc. It is the 3.36:1 step up ratio (higher than the typical 3.05:1), is a polished housing and is the type designed to be on the passenger side of the motor with the inlet facing the radiator. It will be great for lt1’s. It will be for sale soon.

(what I didnt realize - was that I could have gotten more out of my p600b. Procharger makes an M1-SC curved inpeller for the p600b. It was originally designed for marine use and their technicians can install it...(the phone reps were clueless about it). )

so back to the d1-sc...
i modified greg@blowerwork’s p600b bracket to fit a d1-sc blower. I have a drill press so it was easy.


i still have yet to get out and check boost levels. I started with a 3.70” pulley. I just have a normal
Gates belt on it. Looking forward to breaking this thing in
Its raining now so that will be later

no intercooler, but spraying meth/water under boost and I also run a mix of e85 and 93 octane as fuel. At 55% ethanol now.

i do all the tuning

 

Nice
You get more power and it would be nice
How much for the P600b?

 

Just curious; 55% ethanol, or 55% E85?

Pretty sick setup, though!

 

Very nice.

 

lol. (The E15 post...lol)

55% ethanol. I have a digital gage under the dash with a sensor unit in the return line.

while my ecu cant adjust for it on-the-fly like modern ecms. I use the % on the gage to adjust my injector constant on tunercat on my laptop before uploadimg the tune to the moates adapter (plugged into my ecu).. I trick out the injectors to run ethanol by tellimg the computer i have smaller injectors than i really do (i learned this from bjankuski. Thank you)

 

Wow-Good to know that the P600B bracket can work. Did you have to use any spacers? I also have Greg@Blowerworks bracket.

I am hopefully firing up my 383 LTx with P600B this weekend.

Looking forward to your results!

Steve

 

funny you ask!

yes, im going to need to add 2-3 washers to each spacer (to space the d1-sc blower pulley/body closer to the radiator) bc i just noticed my belt jumped a tooth at the harmonic balancer

 

On my 1992 I moved the radiator about 2.5" towards the front.

 

$1300. Fresh seals, and inspection from procharger clean bill of health.
that also includes the oil system lines (return and feed)

i also will have the original procharger brackets for sale separately.
and an oil pan with a bung welded to it for the oil return line.

 

Looks REALLY nice!

 

Good stuff! Yeah, was just checking my octane math. Very, very cool to see a modern piece of kit being used to tune in a very old-school way. It's really nice seeing people who still know how to do romulation in 2020.

 

Can you explain the process how you make this adjustment .Is there a Mathematical formula or approach to this?. Would love to learn how this is accomplished.
Thanks

 

Check this out:

https://www.ecmtuning.com/wiki/e85fuel

Essentially the formula you're looking for is "({Ethanol %} x 0.613) + {Gasoline %} = Fuel Ratio" to get the fuel ratio, and once you have that, use the formula "{Injector size cc/min} x {Fuel Ratio} = Programmed Injector size cc/min"

The reason for this is because it takes more fluid to achieve the same combustion when you're using more ethanol. So if the computer thinks the injectors are smaller than they are, it will compensate by increasing their duty cycle to try to flow more fuel through them.

 

yeah i have a wideband o2 (behind drivers side collector) and datacat tune software

i try to target 128 or 14.7:1 across my VE low rpm table.
blms have always been split so i tune it best i can. One side is like ‘120 and the other side is 136)

ive created a list of injector constants for different % ethanol to get that 128...

unfortunately its not as simple as just producing that list bc, ive also fine tuned the ve table to further dial it to 128 for all MAP and rpm values.

but obviously higher % ethanol = lower injector constant (lb/hr)

ive also tweaked the spark adv tables for a little more advance as % ethanol goes up

 

Ok, ive spent the weekend shimming the spacers on the bracket (remember it was designed for a p600b, not d1-sc)....

i must have the blower on and off 3x to get this right (so that the belt doesnt jump a tooth when i get on it).

in the photo, ignore the chrome multipoint bolts in the foreground , instead look at the plate spacers. Notice the 3 washers ive used. This was the sweet spot.

the blower is still .007” too close to the radiator (as evidenced by starting the engine with a loose pulley and noting how far back it slides on the shaft)






I took the car on a test drive and got up to 5200 rpm in 2nd gear. Afr shows leaning trend With rpm (it was dialed just right for the p600b).

I had 11 psi max boost at 5200 rpm with the 3.70” pulley. Thats right where i want to be.

also had 4.5 degrees knock retard - which surprised me in the cool air

 

This is cool that you were able to use the P600B bracket!

Its going to run great with that 4.10 step-up ratio.

 

yeah im spinning the blower at lower rpms. Im hoping this translates to less heat build up at higher boost

i mapped the boost curve of my d1-sc (and 3.70 inch pulley ) vs the p600b on steroids (with a tiny 2.625” pulley, & a gates rpm belt) and the p600b was like a rocket. It made more boost than my d1-sc (with 3.70’pulley)


on the attached boost graph (MAP kPa vs RPM) , there are 3 pulls on my p600b maxxed out with the 2.625” pulley and gates rpm belt.
The highlighted series below those (looks like blue dots w/ X’s around the point) is the d1-sc with 3.70 pulley

that p600b is a great blower for anyone with a stock bottom end lt1. I also liked how it weighed less (due to its external oil system) and had an external oil feed.

of course ive got more room to grow with the d1-sc

 

Thanks for sharing this info. We’ll see how the P600B works with my 383. I have 10.3 compression with a 2.65 pulley.

Nice that you will be able to grow with the D1.

I fired mine up today for the 1st time and it sounds cool. Once the tuning is completed I will take it to the track.

Good luck with your new set up!

 

Do you have a forged crankshaft, connecting rods and pistons?

I am starting to build a completely new engine and the intention would be to build a 383 with my P600B supercharger but I am trying to reduce the compression ratio to about 8.5

Wasn't 10.3 a pretty hard compression ratio for the supercharger?

 

no, stock bottom end lt1 with 86000 miles.
compression check came back ok so i decided not to mess with it

I did however LOWER my static CR to 9.7:1 (from 10.5:1 or whatever the lt1 had in 1993) . Its been that way since 2011.
I did this by putting on aftermarket AFR 195 heads with bigger chambers. I believe the ones i put on were 61cc (if i remember right). I did all the calculations and came up with 9.7:1 or so static CR.

I wouldnt run 8.5:1. You dont need to be that low for a centrifugal superchager (unless you are planning or running 30 psi boost).

Id stay in the 9.5-10:1 range. A lot of the ls3 guys run even higher compression that that with boost. Maybe they also run e85 which helps out with that.

(and the newer direct injected v8’s are an entirely different animal. Not comparable with our engines. )