Brisk

iTrader: (25)

OK guys... I'm at a crossroads. Perhaps I should have posted this in the general engine forum.. but I want the opinions from the forced induction guys.

I've been building up my 305 and its progress has been pretty good in my opinion, check my vbGarage for more info. LT4 Hotcam, aluminum L98 heads, 1.6 roller rockers, headers and full exhaust. The car runs good and pulls decently in the higher rpms, but I've lost alot of low down torque... alot. I've got a nice bigmouth intake, slp runners, and mega-ported plenum ready to install which should make it breathe alot better.. however won't that make my torque more mushy and simply give most of the benefit to high rpm horsepower? Lastly I've got a rebuilt L98 350 bored .030 over ready to go, but I think swapping everything over will only yeild me a small increase in HP and a marginal increase in torque?

I've come to a realization. Torque is king on the street, period. The reason I was initally attracted to camaros (and more specifically the TPI's) is the low end, basement torque. Sure they didn't rev up, but from 0 to 4500rpm they are fun as hell to drive.

So I thought I'd try to fix that with cam, intake, etc. I achieved my goal only to take away from another aspect. Now I have more high end, but I've lost a considerable amount of basement torque. I want my torque back!

So this is where I stand at the crossroads, where do I go from here?

I think a kit avaliable from ATI procharger would fill my needs. I want low end basement torque, be fun to drive on the street and burn rubber, and yet still be able to pull hard for highway use. I'm not a racer, I've never seen a track or dyno. I could care less about 'numbers' and 'times', or whose faster. Butt dyno and fun factor is all I'm concerned about.

So super charger guys where do I go from here? I've been reading until I've gone cross-eyed. From what I've summarized, a procharger is the best choice. Quality, reliability, ease of installation, flexability, and it is a complete bolt on kit, ready to install and drive in one day. I've read some bad reviews about paxton and vortec, but nothing really negative from ATI. The downside seems to be ATI is more expensive then the rest. Where is a good place to buy a kit from?

Ok so here is what my engine is; 305 roller LB9 block stock and untouched bottom end with about 80,00kms (about 55,000 miles if my math is correct) Stock crank, pistons, etc. Currently LT4 hotcam w/1.6rr and 58cc aluminum L98 heads, stock intake, plenum, and runners.

The cam is probably not an ideal choice for forced induction and I'm not opposed to chaging it. I've got the stock LB9 cam and an L98 cam sitting here, or I can buy a purposly ground cam and install it, no prob. I've also got my stock heads still kicking around. I've got all my stock parts, so I can have it back to stock at any time.

I'll assume I'm still at stock compression which my manual says is 9.3:1 although the head change may have bumped it up a bit.

So if I go the SC route, where do I start? Do I put my engine back to stock, then install the SC... or install it as is?

How much boost am I safe for, and at what octane rating? What else would I need to buy?

From what I gather, 24lb/hr injector increase is manitory and minimum and perhaps a high flow fuel pump? I can sell off some of my parts to help fund a SC, or should I keep everything? (L98 block, SLP runners, intake, etc) Obviously I want to build a good full package motor, but if stuff isn't needed I'll definatly get rid of it to help fun a SC.

Help me make a decision, give me your opinions, and show me some pictures! Ideally I want to run as low octane fuel as possible with as much boost as I can safely get away with... then mabey next year I can do a piston swap to drop the compression (and mabey heads?) and add more boost. Lets try to keep this on topic, I want to stay away from NOS and while I'm not opposed to turbo, I'd like to learn more about superchargers first.

Lastly, whats the difference between ATI's P600B and P-1SC, other than price?

Whew, I think thats it. Thanks!

Brisk

iTrader: (25)

Ok I think I found the answer to this question, someone please correct me if this information is wrong.

"The difference between the P1-SC and the P600B is that the P1-SC is "self contained," which means that the head unit isn't plumbed into the engine's oil supply. With most superchargers, oil is pumped from the engine, through the head unit and then back to the oil pan. All of this oil plumbing, so I'm told, takes a significant amount of time when installing a supercharger, and most people are a little squeamish about the idea of punching a hole in their oil pan (for the oil return line). The biggest benefit of the P1-SC then is that the installation is significantly simpler and faster. Also, because the engine and supercharger don't share oil, you don't need to worry about contaminants in one damaging the other. Another difference is that you must actually change the oil for the P1-SC regularly (pour right into an oil fill hole in the top of the head unit), whereas with the P600 changing the engine oil also changes the supercharger oil. The P1-SC may also be quieter (not sure about that), but that was not the primary intent when ATI redesigned the P600."

89onlyZ51

iTrader: (3)

The P-600B and P-1SC are really two different units. The p1sc has an impeller designed for slighty higher maximum speed than the p600b, and the internal step-up gear ratio is significantly higher (one pulley turn=3.5 turns of the impeller on the p600b while one pulley turn=4.1 impeller turns on the p1sc). The bottom line is the p1 is designed to make more boost per engine rpm than the p600b.

jocool

Also the internal step up gear ratio on the p1sc allows you bigger blower pulleys for more belt contact(less slippage). The p600b is probably a fine blower, but if given the choice I would go with the p1sc or better yet D1sc.

vwdave

The LT4 HOT cam and aluminum L98's IMO are way too large for a TPI 305. That cam is not going to allow for much low speed air velocity which is needed to generate torque.

If you changed just the engine with the stock intake on there, you will gain some low end, alot of midrange, and not much top end. If you put the intake mods you have on there with the new engine you will gain some low end, decent amount of midrange and a ton of top end.

If you want the best of all worlds, you should put your 350 in, change the cam to maybe a xe262hr or something similar, put the intake on and leave the L98 heads on. You should make a good amount of power across the whole band with that. BTW, I think the 305 has 58cc chambers, so your CR should still be 9.2-9.3:1

Brisk

iTrader: (25)

right.. so if I put on the tpis intake, slp runners, and plenum it will make things worse in the torque department, correct?

this is why I have been considering forced induction. if I add a procharger to this combination, wouldn't I have alot of basement torque combined with good midrange and high end?

vwdave

At the bottom of my post (not quoted) I told you the easiest way to fix the problem.

Brisk

iTrader: (25)

yes I read that, thank you.

My car and 305 currently has about 55,000 miles on it and is healthy, so I'm not in a rush to pull the engine.. may as well use it as is for a while. What do you suggest I do in the mean time keeping the 305 between the fenders?

vwdave

IMO? Put in a smaller cam.

rideon1200

Didnt say much about exhaust. Do you have back pressure.

calebzman

iTrader: (3)

Supercharge the 305. You'll have more than enough power plus room to grow. Leave the engine the way it is since the compression ratio is fine w/ the aluminum heads. You can always change stuff around later. I'd run premium to be on the safe side. An intercooler is a good idea too. Also, be sure your fuel system is adequate and you have a way to take out timing.

Brisk

iTrader: (25)

Ok, but would you supercharge it then?

Hooker 1 5/8" headers, custom 3" y pipe, !cat, and 3" flowmaster cat back system. Its all in my vbGarage.

ok, thanks. I was looking at the P1SC because its self contained and comes with an intercooler. What would need to be done to my fuel system, and how do you mean 'take out timing'? Retard the timing with a timing light?

___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___

Thanks for the replies everyone. I noticed someone mentioned to go with the D1SC and I've read many people using that unit... however do they make a pulley small enough to use on a stock 305?

vwdave

I would get a mild supercharger specific cam if youre hell bent on supercharging it.

gcpoland

iTrader: (18)

I have a set up that is pretty close to what you are talking about. It may give you and idea of what to expect.

305 -.030 over
Ported 113 heads with LT4 springs (ported and blended/ flow is 245 cfm@.500 lift)
Comp Cams Ex Energy CS 264H-R12 1.5 Roller Rockers
Holley Stealth Ram
Vortech V1 with 10lb pulley
SLP 25lb injectors
Vortech super FMU with Walboro aux fuel pump.
Wideband O2 with data recording

I spent a tremendous amount of time tuning the engine before I even put the belt on the Supercharger. If you don't get the tune right on this, it will never work with boost. Get used to burning your own chips.

After getting the tune close, I hooked up the SC and started tuning that using the Super FMU and dial back box. I could get it close but still had to go back into the ECM to finish up.

The car is great fun to drive on the street and play with on the strip. If you have the time to dedicate to tuning, you will enjoy the SC. If you don't have the time, patience or tech ability to get everything tuned correctly, you will hate the SC. It is NOT a bolt on and drive modification. Bolting the kit on is easy, tuning is not and can cause serious drivability problems.

Feel free to ask any questions.

Gary
NH

sleepybu

what dose it cost for the hardwere to do that and where can one get this stuff

gcpoland

iTrader: (18)

My favorite is www.moates.net