After racing a turbo mustang that ripped I was wondering about a turbo on my car. With a turbo what kinda HP/Torque would I get, I know it would need to be a custom job. how much would it cost.

 

The answer isn't that simple. You can make a wide range of power, and the cost can also vary widely. To really answer the question you need to decide what you want out of the vehicle.

 

I want around 380hp, Is that possible with a 305 TPI.

 

i'd say that's a pretty lofty goal for a stock 305tpi with forced induction, but it's certainly possible. That would require somewhere along the lines of 12-15lbs of boost on a stock 305tpi, and you'd need to do some work to the bottom end to support those boost levels over any period of time imo. Or you could do it with a head/cam package and less reliance on boost. Anything is possible though. On thing that is sure is that there are no buy it and bolt it on turbo kits. You'd need to piece something together, and you'll need to know someone who can weld, that's a given.

on the other hand, you could probably build a pretty mild naturally aspirated 350 to make that much horsepower that would cost a lot less.

 

Sure, but on a stock(ish) 305 that would mean about 8-10psi boost, which would be at the ragged edge of what you could get away without race gas or possibly a REALLY GOOD intercooler.

 

The Bu runs ~10-12 lbs of boost. Running 93 octane, rarely ever see any knock retard. Usually...Last run at the track MAT temps were 53C at the line, 66.4C at the lights. Horrible run, went way lean (lots of knock retard) and shredded the belt (which is what promted redoing it.) Really screwed the pooch that night.

However the 305 is about done.. with lots of blow by and the oil pressure is ~10 to 25 psi hot. But so far its been a timex motor.

BW

 

I was under the impression that your tpi 305 wasn’t exactly a stock tpi engine. 9.3:1 compression, iron heads and a relatively small cam do not add up to great detonation resistance, though admittedly the 305’s seem to be more tolerant then the 350’s (my 9.8:1 305 is nowhere near as cranky as my 9.3:1 350, both FI, both in f-bodies in front of the same tranny/rear gears, both iron headed).

The fact is that most people with stock(ish) engines tend to eventually get themselves into trouble with 7psi (but most will admit that whatever happened was their fault).

 

The short block is stock with cast dished pistons, and other than a mild cam (214/224@.050) the only change was the heads to iron 350 TPI (64cc IIRC). Compression for a 78-80 305 ~ 8.5 according the the source I looked it up in. I can't say exactly what the final comp is since I just bolted it together with no intent to keep it for long. I figured she go bang by now..

Anyways, the 305 did what I intended, now on to a more purpose oriented 355 or 383.


BW

 

Huh, exactly my point. An early ‘80’s 305 (should be 8.4:1 with stock 55-58cc heads) with later L98 heads (64cc probably the crappiest small block head made in the last 35 years with the possible exception of the L03 heads) with no decking and normal thickness head gaskets should put you in the high 7.x:1 range, ie: the “go ahead, you want to run 20psi on 87 octane, I can take it” range.

The mild cam (which is MUCH bigger then stock, especially if he has a peanut cam) has ~20* more duration then the stock cam and most likely a tighter LSA which would also make the engine more boost tolerant.

My original point was that your TPI 305 is built like something intended to be boosted, his (if original) is just the opposite and will not tolerate a fraction the boost that yours will.