Swore this latest one would remain stock, period....but cant help and wonder about doing a cheap smog legal 383 or 400...however I have never built my own blower motor only fooled with others. The torque is nuts on them and it never stops it seems

Say you ran 5-6 lbs boost, what kind of longevity are you guys getting out of these setups? How often do you need to rebuild them?
Any heating issues, regrets? If you had to do it over what would you do differently or just stay NA?
I may be having to dump my A body and keep a cheaper toy but no way this TPI 350 is gonna keep me satisfied.
If I could make it an honest 12 sec car and pass smog that would suffice I guess.

 

Cant speak for TPI specific

but I would run 12 psi or so of boost

set up correctly (with enough fuel pump, big injectors, and water/meth inj) a stock bottom end will last a long time

i know because im doing it. On my 93 lt1

can even go e85 for more power and safety (detonation resistance), if the fuel system can handle it

 

I am running a boosted Iron Headed L98 with what is supposed to be a 6PSI pulley. However, with 1.6 ratio roller rockers, long tube headers and going to a 3.45 gear, it seems the blower can't quite get over 5 PSI any more. I have converted over to an EBL system so I could get my tune dialed back in.

This is a hot air kit from Vortech, at 6PSI intercoolign isn't even needed. However, I did find that even with the booster pump at 43.5PSI static pressure my 22lb Bosch 3s were going to 100%DC under boost. So, there is not a lot more there. With a 1 degree per pound of boost strategy, and a little doctoring, I don't see knock counts very frequently on 93pump gas.

I have turned my AFPR up to 50psi static and am working the VE tables now. The boost-pump and FMU still provides fuel at 56PSI so we will see how it goes.

I say that to say this. Under normal driving conditions I barely ever see any levels of boost, I am not getting any knock, and I wouldn't see why it wouldn't live as long as you would expect a stock set up to last if you are just street driving it. However, without an injector change, you can do the math, rule of thumb calculators say that supports around 325 crank HP. However, if you are building a 383 and can go with bigger injectrors, keep the timing sane, I don't see why you can't get a 12 sec. pass on a relatively safe boost level/tune.

 

Keep it coming...diz 12 lbs is more than Id wanna run in a cast 2 bolt setup.think 6 tops will get me by
Not trying to make it super fast just maybe surprass the 500 lb mark;enough to be fun
May look into seeing if I could convert an LT1 intake and make everything work for smog not so sure.

 

My ‘89 has procharger p600b w/ 7lb boost. Dyno at 313 rwhp, 407 lbs tq. Car now has about 75k on it with no issues.

 

5lbs is nothing. 450hp on a 2 bolt is safe. I'd maybe swap out the main bolts but thats about it and only if I were going in there. If its healthy it should be safe for a while.

 

Cool, sounds like a possibility then..Driven a friends chevelle (heavy) with a 142 weiand, cast crank 383 with crappy heads. It pulled a 3.08 gear way better than I thought, that should be enough to keep a C4 interesting. Wont intercool, not going for every last bit. Has to be reliable and smoggable.
Dont think the LT1 intake will work, EGR, switch and all that has to be moved, monkeyed with. Wont pass visual so Ill stick with the TPI.

 

boost on a stock tpi will be fun. It will have the same fun factor as an old big block car that can roast tires on command due to the exaggerated torque curve provided by the intake.

 

The centrifugal still relies on RPM to make boost. It is more linear, but does come on a bit like a turbo with a spool up feel, just more predictable of where and when it occurs. The 6PSI pulley doesn't provide enough turbine speed to reach much boost down low. I would have to look at one of my data logs to see when boost starts to build, but it is not as immediate as a roots type.

It is however very fun. You still have the low Torque from the TPI and you carry that to the shift point. It does not hit a wall like TPIs usually feel like.

 

True. But you could under drive the pully a bit to get it to come in early and then whatever it hits it hits right? On a tpi you probably aren't spinning it much past 5500 anyway even under the best circumstances.

 

Yes, the faster the turbine speed comes up, the earlier you will see boost. It is all about ratio and the TPI doesn't reach high RPMs, limiting turbine speeds. I am contemplating larger runners, bigger injectors, intercooler, and 10PSI pulley for mine. Or, what is supposed to produce 10PSI.

Boost is back pressure. It's not, in and to itself, what will break anything. Too much torque, too much RPM, or knock is what causes engines to fail related to boost. You made reference to 450hp is safe. Well, maybe, depends on what RPM, but in that theory, I agree. As long as you stay with force levels the bottom end can handle, in an RPM range your valve train can handle, and a safe tune with no knock. You should be safe. Don't forget that boost also reduces valve seat pressure (Boost pressure over valve area results in a force working against your valve spring), too much boost coupled with too much RPM and valve float will show up early. I see absolutely no reason why a 6-8PSI kit wouldn't live forever on a street driven SBC as long as the tune is right.

Side note: My current 6PSI kit only sees 5PSI now. I read an article from Hot Rod (I think, maybe Super Chevy), where they put this same kit on a 305 and did some testing. It ran higher boost than it would have been capable of making on a 350/383. I think they were seeing 8-10. My 350 has been opened up with headers, increased ratio roller rockers, no cat, and flow through exhaust. So, it breathes a bit better. Then the trans has a shift kit, turning an aluminum driveshaft, and 3.45s out back allowing it to accelerate better. All that together shows a hair over 5PSI max boost.

What I have seen is the factory AE is not capable of keeping up with the extra hit of air when the re-circulation valve snaps closed. I am still working on that in my tune, I definitely get a quick lean spike that I am working on getting out without causing bogging.

 

I mean all it comes down to is that boost is still pressure which is still resistance to flow. Thats why the same car with crappy parts will make 8-10 psi and x horsepower but with better parts better Flow, porting, etc, makes less boost but more power.

I'm not all that familiar with forced induction but the principles still seem to be governing engineering crap I learned over the years...

And I feel you with AE, even on mine there are certain areas where if you mash it it dips lean. But i can't help it with wet flow.... there will always be a smidgen of it in mine.

 

BBC torque would be nice..this one has the tall 2.7? rear gear, may not need to regear
Unless heads are in budget at the time I may just port the stockers..

Car came with a new Edelbrock base and SLP runners I ported many years ago..outsides are all polished to boot so that saves $.

 

Have an 85 with vortech blower, has been on the car over 10 years no issues with 8 psi boost.
As long as it is part of a kit you will not run into problems, depending on your milage blowby (combustion gasses bypassing the piston pressurising the crankcase) can become a problem forcing oil out of your seals and dipstick tube. You need to block your vacuum to rocker cover and PCV.

I did rebuild my engine at 170,000 miles mainly due to oil leaks from excessive blowby, plus wanting to run more boost requiring forged pistons rods and crank.

 

if forged, why are you only running 8 psi ?

 

Am currently running 14 psi boost, i did try 20 psi but was pushing it for my current compression ratio and belt grip.

8 psi was what i was running on the standard engine.

Boost level on vortech v1 was governed by crank pulley size limitation to crossmember, had to modify the crossmember so i could fit a larger crank pulley to run more boost with the vortech step up gearing limitation.

 

As with anything it depends on the tune. You could build a low hp non supercharged engine and blow it up the first time out if the tune is whack.

I’m running a bone stock (internally) 1990 L98 in my vette with a single GT45 turbo at 11psi making 360rwhp and 550ftlbs. It’s fun. It’s tuned very conservatively on a microsquirt EFI with good cooling and I expect it to last indefinitely in this form

 

I'll chime in.

Bone stock bottom end (crank/rods/bolts/pistons/bearings/rings and ring gap)

Big cam, 10.2:1 compression, good flowing heads, pump gas - blow thru carb, 16+psi, 6,800rpm, almost 30° timing, and gap insurance on top of that.

Keep the charge air cool (water/meth injection), feed her lots of fuel (10:1 AFR) and give her hell.

 

fk yeah now youre talking!! Got any pics or build links?
I only wish....with ca smog we are strangled. 383 and tiny cam/heads if were lucky, SC with carb # maybe
Would help crutch this crappy 2xx gear, hate it but not putting a rearend in it.

 

Sure, here ya go! It’s great fun. Does burnouts at freeway speeds with stock 2.59 gearing.