i have a stock 350 tpi and i plan on slapping on a s/c , what else should i do to the motor to trick it out for street so it will match the added power? money and time iare not problems. im in iraq now and plan on having something to toy with when i get home.

 

I'd be looking into a nice set of headers, maybe even ceramic coated for rust prevention and cooler temps. Various companies offer them already coated. Long tubes are always a nice thought, but depending on the application and how much you really want to work with them they can be over kill. Last time I checked they require a smaller starter, modifications to the k-member, maybe shorty spark plugs, and purchase of a new y-pipe or fabrication of one along with connecting that to the cat-back pipe. Which in itself can cause problems if you want to keep emissions legal. Also would be a good time to upgrade to a cat-back system.

It would be a good idea to do regular tuneups on the fuel and spark areas. If money is no problem I would look into a MSD or Jacombs box and coil just for the fact all our stuff is getting pretty old now. I know a few members on the board really like the Jacombs coil due to the high voltage rate.

From what I've read the stock 350 TPI cams are very boost friendly for starters.

You might also look into methanol/water injection as an added cooling effect, but depending on boost levels might not even be required. The kits are starting to become more popular and Summit is even carrying them now. Lots of good posts of the forum over that subject, so it should be easy to use the search feature.

I know some users really like the Carrrol Supercharging SuperFueler Unit over the FMU provided with the kits. I looked into the idea few years back, basically it mounts 3 injectors after the throttle body on a plate. There controlled from a stand alone box that is boost refrenced. It has 10 different setting points (if I remember right). Each one is adjustable so you can control the flow of the 3 injectors at a certain boost level. It allows you turn the **** to control the added fuel at that given boost level, which lets you highly tune the air/fuel ratio.

 

if money isnt an item, you might consider switching to a better manifold like the holley stealth ram or even a dfi setup, hell mind as well build up a nice little 350 to get the most of of the supercharger, when dealing with boost fuel and spark are deffinately something to also upgrade, bigger fuel pump and maybe injectors, maybe an msd ignition system. exhaust is anothing thing not to forget about, with all that extra air coming in its gonna need a place to go, so headers and hi-flow y pipe might want to be in the list of things to get. Theres a million other things that you can do but these are just the basics, and like has already been said the stock tpi cam is blower friendly so that wont really need to be addressed. good luck and stay safe out in the suck, might be tag teamin you out and me in here in a few months but who knows..

 

I would change the plugs and add better wires like MSD. Also upgrading to a MSD box and coil help a stock car and are almost a nessary for a boosted car. Exhaust is a must, you are going to want to get coated headers so everything under your hood has a chance of not melting. SLP or Edelbrock are good, 1 3/4 are what I would choose for future upgrades. Other mods would be for cooling, more power means more heat. A larger radiator and an oil cooler should be seriously considered along with a larger transmission cooler (and maybe a larger trans pan as well). The only other thing would be a larger high volume, high pressure fuel pump so you don't have to use the Vortech inline pump. Once you have the blower on the car you can upgrade things like throttle body, intake manifold, cam and heads ect... as you go along.

Were are you stationed? I am located at Fort Hood Texas, I have done just about everything to our cars included converting a TBI 305, 5 spd to a 350 TPI. So if you need a wrench I am around, good luck brother

 

hey guys, i deffinatley appreciate all the info. im fairly new at the performance thing but im a quick learner. me and my little bro have a thing for f-body rides. it just gets into your blood! kinda like hep but without the negative side effects.
ive been in iraq but im being transferred to kabul, afghanistan. a couple more years and ill be on the way home to trick out my new toys.
hey you say your in fort hood? im origionally from belton. right next door to ya.

 

What kind of supercharger? Roots or Centrifugal?

 

nice body kit, how much and from who? Factory 5 racing?

 

thats a good question. what is the difference between roots and cintrifugal? what would better suit my stock tpi 350?

this body kit is from Evolutione you can run a search on it in google to find it. you can also find contact info from
www.k-1attack.com the kits runs just under 7 g's. i got lucky and foud this kit that was short a couple interior pieces and a donor car with it for $5,200. on ebay.

 

Yeah its more than a body kit, its a kit car using the 82-92 F-body as the platform. Good find, I would have jumped all over that auction too. Those kits are no longer produced.

Roots would mean boost at lower RPM levels, IMO a great match for the TPI. But the thing is, most Roots superchargers I see for sale are made for Carb'd cars, not EFI. I have seen some guys do custom stuff and make a Roots work with the TPI, I think one guy (Saturn5?) got two Roots superchargers working with the TPI, so twin supercharged. Most of the superchargers I see advertised to fit with the TPI are Centrifugal, meaning the boost characteristics are somewhat similar to a turbo. So it would build boost at the higher RPM's. This is a setup I have on my stock L98 w/ TPI (Vortech S-Trim). I consider it a horrible match as the L98 powerband end saround 4500-4800 RPM and you dont start boosting until after 2500rpm. So you dont really maximize the potential of the centrifugal supercharger. To maximize the potential I would say modify the engine for higher RPM power, pull hard to 6000 RPM. A intake and cam change would make a big difference, but the stock heads would still be a restriction. If you could afford it I would do heads, cam, and intake. If you cant do the heads, do the intake and cam. Re-tuning the car is very important if you go this route.

 

yeah i plan of doing everything i need to do to make this motor work right. my plan is to have power on tap when i need it. money is not an issue. i want to do this right the first time and not have to worry about it until something breaks.

what do you suggest doing to the heads or do you suggest replacing them altogether? would porting and polishing be enough or should i modify the valve train also?

 

Also, roots are a blower. There a positive displacement type, meaning they're always moving air while turning. Also they're hard to intercool, it can be done but will run a good extra $2k for the kit from theblowershop.com or similiar place. If you go the eaton method look to spin lots of time fabricating because that setup mounted over the valve covers was a complete custom with an intercooler.

If you're looking for one I would recommend the Procharger D1SC kit. It's selfcontained unlike the Vortech, so you have 2 seperate oil supplies for the motor and supercharger. That should eliminate chances of contamination between the two. You will also not have to have a fitting tapped onto your oil pan. They're a little more expensive but come with an intercooler. Theres been members here running 10 lbs on stock 350s with a little precaution.

If money is no problem I would just get rid of the stockers and go with a set of AFR 195s with the highest chamber CC you can get. That should lower your compression more for more boost. Not to mention stuff gets expensive on stock heads when you start taking out the valves having ports ported/polished, studs tapped (there pressed in on stockers), larger springs install... etc. Aluminum heads will give you more of a cooling effect, which should allow more boost.

I would also get a nice set of roller rockers.

 

i recently had an idea to install a smaller underdrive pulley with the supercharger to get higher boost at lower rpm levels.

does that sound like a good idea? foresee any problems with this setup?

 

I would just dump the Tbi/computer and get a nice carb crate engine.It would be alot easyer to a person new to performace.It will get you back to the basics and not having to deal w/ tunnin,Chips and emissons controls.

If money is not a issue then the sky is the limt on engines but i would just get a soild 350 or maybe a 383 and beef the tranny.the get a good set of gears that will match your combination.
425Hp/460TQ -383-
330HP/380 TQ -350- High Output


i think that would be plenty of power DOnt you???

if not enough a stock engine can easily take a 100 shot of NOS.
which is 100Hp.

so now your looking at 525Hp or 430Hp w/ keeping good driveablitly.

 

i appreciate the advice but im not going to carb it. "the easy way is not always the best way" so says my grandpa. i can do the carb thing with my hands tied behind my back. just as much as i want to stay with tpi, i want to learn about the way it all works.

and when i said money is not an issue, i meant to an extent.
the motor in the car runs great, but im increasing the wieght of the car and feel i need some more power. im not looking to race this car. just want it to perform with the extra weight and maybe a little more.

again, thanks for all the advice. it has deffinately givin me some direction.

 

I think you need to set power goals as well as other stipulations as far as what you want out of your setup. For example streetable manners, certain MPG, certain boost level, reliability, keep the A/C, etc, etc.

What year is the car? Our cars come with good ECM systems (MassAirflow/SpeedDensity) but keeping it or changing it would depend on if you are willing to do DIY tuning, or if you can find someone to tune it for you. Good chance the stock tune will need to be modified, so if this isn't going to be possible for you with the stock stuff, you might want to consider going aftermarket as far as the ECM. Either way I would change the TPI for something suited towards a higher RPM powerband (LT1, HSR, MR, SR) and then pick a good heads/cam combo to match. Don't forget about the fuel system, be sure to plan that out.

 

You dont want to get to high in the hp. The stock 700R4 will not last long over 300Hp.

 

I know that spark has been mentioned but dont forget to gap the plugs smaller and run a step cooler plug....

 

yeah i agree with the tranny prob. ive already got a th350 tranny with a junior shift kit installed. i believe the diff is 3.73.

i talked to a few others and slept on the idea. i believe i will go back to a carb setup.
yeah, yeah, you were right. hehe
ive got a edelbrock 750cfm double pumper, manual choke that ill slap on there. but now the question is hood clearance. if i go to a carbed setup and add a Roots supercharger. will i have a hood clearance issue? the car is a 1991 camaro. also ive seen ads for Centrifugal but not Roots s/c's.

 

Yes, more than likely you will have clearance issues. As in your case a 2"-4" cowl is probably not highly available.

Please see the Tech Article on Installing a 142 Blower

In general that should answer most of your questions. You could always make a centrifugal into a carb setup if you wanted. It would take the base price kit purchase then a few more items.