Been doing some research on using a roots s/c on a tbi set up. I know the trucks have kits.

However not finding solid information on our vehicles.

From what ive read a roots s/c + holley carb/tbi adapter plate will allow the S/C to bolt on. Is that true? Also thinking to make this work I would need to run a 4 bbl? not sure on that.

I would be using a 305 TBI with EBL Flash to tune. cant say injector size or fuel pump yet due to i need to know which S/C to use.

So any info on if using a roots blower WILL work with supporting mods for all around $2000.

Already have the engine and EBL Flash.

 

does it have to be roots? basically you'd buy the truck system for TBI cylinder heads, and try to tune it. Im sure it has been done. The search should have brought something. May be under the power adders section of this board.

 

Well I know they make a centrifugal bolt on for our engines but i think id prefer a roots. Its what im familiar with.

I cant find any truck tbi kits right now either

 

Do am I right to believe with the supporting mods a say eaton roots sc will work with my tbi with a carb/tbi adater plate

 

technically it should be that simple. where you may run into issues is with the pulley on the snout end and the accessory drive system. also tuning is going to be fun and you will need to get a 2 or 3-bar map for the boost.

 

Superchargers have come a long way since the Weiand/B&M design. I would look at the E-force line from Edelbrock. This is also one build I would use 350 vortec heads on a 305 for, to lower the compression. A modern supercharger with a bypass valve will not really hurt your fuel economy out of boost and with an 8.5:1 compression ratio I would run about 10 psi of boost.

 

From my understanding the e force bolts to the vortec heads. But what about the tbi? I'm only worried about the physical aspect right now. Getting it to bolt up mechanically

 

[QUOTE sc will work with my tbi with a carb/tbi adater plate? ][/QUOTE]

Manifold vacuum for the MAP sensor is under the TBI blades in TB. If TBI unit on top the blower unit will that not cause some problems? If TBI is sitting on top the blower then where to locate the MAP sensor?

Would not a centrifugal blower be a better choice?

 

Manifold vacuum for the MAP sensor is under the TBI blades in TB. If TBI unit on top the blower unit will that not cause some problems? If TBI is sitting on top the blower then where to locate the MAP sensor?

Would not a centrifugal blower be a better choice?[/QUOTE]

The centrificals build boost as the RPM climbs. The positive displacement blowers build boost the instant teh throttle is opened. Torque rise is much quicker with a good positive displacement blower.

As for the SC it will work with the TBI unit on a carb-tbi adapter plate. You can use a 1-bar sensor in the standard location or a 2-bar sensor in the manifold under teh blower.

The E-Force bolts to Vortecs which would be a wise upgrade to your TBI heads in a supercharged application.

 

I see. Now that I think of it that makes sense. Where would one tap into the manifold for the vac to feed the 2 bar? At the location of brake booster? Come to think of it that is where I added a nipple for my VAFPR(Aero) but that is vac.

I believe with the EBL the 2 bar is mandatory. A fuel pressure management devise may be out dated due to modern aftermarket ECU's..

 

Exactly. It's not that one is better than the other, they just put the power band in different places. IMO the grin factor is better with a roots blower on the street, (if you get traction)...

But on the drag strip I'd opt for a Procharger or better yet, a turbo because the boost will come on strong after you're moving and a bit higher in the RPM band. Not saying they won't work well on the street either - just don't expect instant response like with a roots type blower. I assure you, others opinions WILL vary...

You might want to look at Magnuson's MP122H - almost identical to the E Force, but with 200% better customer service and support. As you can tell, I've had horrible service from Edelbrock...and if you have to deal with their warranty department...good luck to you.

EDIT - There's a member here that uses an aftermarket TBI system with his, and it's sweet. There's a small (1/8"?) tap for blower boost reference at the base of the blower along with two larger additional taps near the top of the blower for power brakes or PCV on either the E Force or Magnacharger. Not sure about the Weiand's.

 

Hello,just joined.Took an 89 TA in trade and lovin it.305 tbi,smog went first,made some shorties,built a stroker out of a 68 high horse dz302 for it and changed my mind.Dropped compression to 8.0,forged pistons two valve relief.2.02,1.60s-dont use hyper or 4valve,you'll hit em or detonation problems.Useed carillo h beams,scat crank.Went with a whipple twin screw for trucks,same computer for 5.0s or 5.7s.Whipple says they dont wanna know about it.Works on 88 to 93 I think.Internal oiled,bolts right on.Make yourself some longer fuel lines and hold on.Powerband is a straight line.Swapped the 16x8s for 9.50s front 11.oos in the rear.This thing is fantastic.Went to solid full rollers with rev kit.Up to 7500 rpms got quite a bit left.Gonna spend this weekend making a cage for it,gonna go out and try to race scca vintage.Just getting started on it.

 

thier is a whipple supercharger for sale in the for sale section on this site.

 

Whipple came pre-set at 8lbs boost.Pretty easy to override and change on the fly.I really like this 4l60e but I gotta do something about my stall converter and driveline before I get too carried away.Really like this lsd on the bird.Had it up to 25psi probably go 30-31 pretty easy.Runs a little warm,brakes getting hot,no air to lots of stuff.Time for the plasma cutter.I'm kinda used to it from c4,sc5,s.Easy fix.Wish I'd got a TA a long time ago.

 

I'm looking at doing the same thing, so be sure to post your progress.

 

Decided to go nitrous. Doesn't affect dding and is a cheaper alternative. Very easy to hide as well

 

weak

 

Yeah its weak to get better hp gains with cheaper costs and keeping my dd reliability and able to remove it in 20 minutes for smog purposes.

If you'd like you can sc yours and come to sac and ill show you how weak it is

 

your reply is weak too

 

Story of your life. To add to this thread, found its not cost effective to sc a tbi with the gains you get. Better to switch over to a carb or tpi platform.

 

To me,tbi,tpi,carb,they dump gas down the hole.thats they do.You mightt have your preerence.Personally,I'd rather have a Gurney Eagle with 4 dual throat webers but I don't know about you but I gotta work with what I got.I traded a $2500 bass boat for this car and a fresh stroker block with AFR0917 heads factory ported and polished.I traded the block fo a brand new Whipple for 305-350 p1ckups,66 to 96,never been installed.Traded some other stuff I've had for years. built my orn shorties and 3 in straight back into 3 in magnaflows in backwards,exit in front of rear wheels.Found a cheapabs body kit and they'll sell me the front cliip for $200.It weighs nothing and is actually aerodyn. great.Ang it's got a 3ft by 1ft mesh grille for cold air and cheap parking lights that'tll make great brake coolers.4 piston front 6 rear.Brembos.I should be able to knock a1000lbs off it.World products Anaheim is making tbi that has bigger annular intakes,stock injectors,but it's got a hand screw fuel pressure reg. between the bowl.8 psi is a joke.I've already made 3 pulleys.Got forged internals.J&E pistons,etc.Incidentally if any of you guys plan on racing one of these,the aerodynamics are a joke.the chin and tail spoiler actually lift the car.Made my own carbon fiber tail.It's ecu-prom I'll need help or suggestions from tou guys.I used to be a pro GT driver.In 85,I was testing tires on a WSC Porsche.One ooooof them was'nt much good.I hit a wall going about 160,spent a tear in the hosp. and lost my left leg below the knee.When Iwent to check on the status of my liscensewith FIA,SCCA and IMSA,they laughed at meTimes have changed.I even had to take special tests for the DOt to drive a tractor trailer.Got tired of that in 05 and started building cars for people.1/4 mile cars.It seems like the racing world has gone PC.I can get a liscense.I've been a driver before I was old enough to walk.I can take somebody for a ride and they will never get in a car with me behind the wheel again.The best part is I can come back as an amateur if I want.I can beat guys in $400,000 Porsches whose watch cost,s more than my 89 TA.You guys can do it too if you want.Foreign car junkyards,racing team castoffs,a bunch of places.Well, there's my life story.Sorry,but it's late and Ifelt like telling it.Never did before.panhead201

 

does anybody know if the new close ratio 6speeds will work with an 89 305? If you're going vortec heads on a 306 you will have pushrod length issues.I had valve issues.2.02/1.60s into a 3.75 cyl.Right now Im set up for a .600 roller cam neecd malift,no overlap.

 

Total GM lamer here... LOL. But wouldn't it be easier, more cost effective and more HP/torque to swap for 10.5:1 427 let's say?
And stick "BBC inside" sticker on a back window or something...

 

Don't know about Roots tbi or Paxton either.I've been using a Whipple tbi twin screw centrifugal made for gm pickups 88 to 96.They ain't cheap but it's been worth it.I'd love to put a 427-435 in everything I own.Maybe put a 409 in the trunk for reverse.....panhead201

 

I remember audi made twin-engined TT once....
I've been debating forced induction vs high displacement forever and can't come to definite conclusion. The only real advantage of blown engine is better fuel economy at cruising IMO, but NA BBC will last longer so even if it's more $$ to build, right?. I am not trying to get into racing, just good-weather twisty's and such

 

Personally id take a blown sbc over a bbc. Preferably supercharged. 350 sbc with a centrifical blower would make a good amount of power depending on the blower and tune.

 

I wonder would Vortec7400 fit in 3rd gen...

 

I had a7400 vortec in a 4wheel drive dually I had ten years ago(6 wheel drive?) and it was probably the best overall engine I,ve ever owned.I had a 454-455 1972 vette and it was a real pain in the &*^()The first thing I did when I got out of VA hosp in 72 was get drunk.The second was buy that car.I left the keys in it for a month cause I did'nt know you had to put it in reverse.If I wanna go fast in a straight line I get a big block.For the twisty turnies I get a small block.I've got a 68 vette 327-375 stroker block and I think I'm going old school.1 wire dist,dual quads,muncie 4 speed,not two guys from MIT to fix it.panhead201