finally

SWAPPING IN A 305, 350 OR ANY OTHER SMALL BLOCK, POST THEM HERE.

mikedamech
I finally get the smurf thing
Posts: 121
Joined: Sat Jan 05, 2008 11:32 pm

Re: finally

Post by mikedamech »

coolen wrote:sorry for sounding retarded here, but I'm confused :rolleyes:

Could you please enlighten me on a TPI set up. I know what TBI is, and that W family engine CSFI? But not sure on the TPI.

Thanks!!
AND NO POKIN' FUN LOL
Well the older ones had 2 injectors and the newer one 96 and up I think has 6 injectors. I bought a multi-port set-up, No popet valves, from linder tech and find it a good alternative.
98 Astro with a 95 LT1
94 Astro stock w/Flo master.
User avatar

potskie
ASV Supporter
ASV Supporter
Posts: 769
Joined: Sat Jun 09, 2007 9:13 am
Location: Waterloo, ON

Re: finally

Post by potskie »

TPI is tuned port injection

Both are generally similar, the main difference is the LOOK, and the fact that TPI has injectors which feed each individual cylinder.

TPI engines generally produce more high RPM power where as TBI produces power off idle. For low end grunt I would run TBI personally.
Image 98 Safari RWD. Stock.
Do you smell what Barack is cookin ?!?!
User avatar

Mr_Roboto
I sleep in my van
Posts: 537
Joined: Tue Sep 19, 2006 2:12 pm
Been thanked: 2 times

Re: finally

Post by Mr_Roboto »

potskie wrote:TPI is tuned port injection

Both are generally similar, the main difference is the LOOK, and the fact that TPI has injectors which feed each individual cylinder.

TPI engines generally produce more high RPM power where as TBI produces power off idle. For low end grunt I would run TBI personally.
Not as much so. The TPI is a serious torquer manifold, you're talking about an intake that gives a 305 350 like torque. In fact if you look at a TBI 350 it's only about 10 ft-lbs up from a TPI. A TPI with the same cam and same compression will make about 25 more HP and 40 more ft-lbs torque than a 305 TBI. Add a cam to that and the different becomes 50 more HP and similar torque. Long runners=low RPM tuning. The problem becomes on a "wet" intake like a TBI or a carb intake is that the fuel can fall out, but the TPI setup has the injectors by the head so you don't have to worry about this. Most carb runners are actually fairly short, there are a few rare ones out there that are long runner carbs from the factory (think very aggressive chryslers)

In fact for about 3-400hp (fuel becomes an issue after that) I would prefer to bulid a TBI setupdue to the fact that you can change its RPM calibration (the intake manifold) cheaply where as with a TPI it tops out quickly without expensive parts like a set of runners and fabrication or porting work on the intake. I can buy two Performer RPM intakes for about the price of one set of new SLP runners. That being said either way is a great way to go.
User avatar

RickU
I am smitten with my van
Posts: 43
Joined: Fri Jan 18, 2008 7:03 am
Location: Chicago burbs

Re: finally

Post by RickU »

91AWDAstro wrote: CFSI.. that's knows as poor mans fuel injection. That's got a single fuel injector with a bunch of poppet valves at each cylinder.
You are confusing Central Port Injection (CPI) with Central Sequential Fuel Injection (CSFI). Both use poppets, but CSFI has a injector for each cylinder centrally located and sequenially fired. Compared to batch fired CPI.
1997 GMC Safari AWD 4" Lift, 31x10.5 BFG A/T, Eaton G80 locker w/3.73 gears, Moog Steering, Rancho up front, Monroe Air in back, Gm 1 ton 4x4 calipers more to come...To see a pic of my new V8 hold down Alt+F4
Image
Post Reply