DrvngCrooner

Hello gents,

Here's what is in my car; the stock 350 TPI, bored and stroked to 383 with new crank, connecting rods, pistons, balancer.

The heads, cam, rockers, intake, exhaust... all the same as they were in 1989.

I've been driving with this system for 15,000 miles and, by today's standards, it's just plain slow. I had to pull the oil pan because my oil pickup fell off (wish I'd installed the bracket the first time) and now I may as well take the whole engine out to work on it.

I would greatly appreciate some advice on what I should upgrade to get more out of this car, specifically out of the TPI system with a 383 underneath it.

Thank you!

LiquidBlue

Check out your rear end gears, and also get that pony breathing better. A different cam, port the heads (or different ones), look at TPI intake plenum alternatives so they flow better, and get your exhaust flowing and then do some chip tuning.

You should be doing close to a 14-15 sec qtr mile as it is. If your not, then maybe you need to tune the beast.

TallTim

iTrader: (2)

Maybe we can keep this thread from spiraling out of control up to "put in the Jegs ZZ572 600HP 572 cid it's the best for you for $13K."

If you tell us things like do you have any cash, are you interested in changing parts and re-tuning, will the TPI stay, what are your short term and long term goals, is it your daily driver or can you afford to make it undriveable for a while?

DrvngCrooner

Thanks for the replies,

I have the money for upgrades, but I don't really know where I should start. I'd like to keep it under 3k if possible. I'm certainly interested changing parts/re-tuning, I'd like to keep the TPI. Right now I think I've decided to get it back together so I won't be pulling the engine.

Short term I'd like to do what I can to get the most out of it by doing upgrades that don't require an engine pull, but that would complement upgrades that require a full engine removal long term. What are my options for the most efficient upgrades while the engine is in the car? I've looked at plenum upgrades but am hesitant because it seems like if I go too big on the intake I'll lose my low end power.

TallTim

iTrader: (2)

You will find in your research that the TPI will be the bottleneck to breathing which is what making power is all about. That said I am of the opinion like many here that the TPI gives the car personality (or whatever you want to call it) so I'm keeping mine despite the penalty.

So are you a "if I had all the money I spent on cars I would ...spend it on cars" kind of guy or a "What! I put 3K into this turd and it still won't run the way I like it - I'm done" kind of guy?

I am the first guy, but my budget is zero so I rely on windfalls (birthday, Xmas, side jobs) to fund what I like to do to my 89. It's also a hobby car so eg right now no plates no insurance.

Like Liquid I'm guessing many here will suggest new heads, cam, and exhaust to free up breathing.

Also like Liquid said the gear change is a great way to make a big difference fast but gear changes are not for the DIY'er IMO. Would probably want to swap the whole rear.

DrvngCrooner

I'm probably more in the middle of those two guys... I want to get as much out of it for as little as possible but won't give up until it's done right. I have the patience to research this and figure it out, but some initial direction is always good. Do most folks go with shorter gearing?

Also if there are any articles/threads that go into some detail about what you're talking about with a proper cam/head/intake/exhaust setup that would be very helpful!

Thanks!

TallTim

iTrader: (2)

TPI and short gears don't go well - you get to 4500 RPM (end of TPI power) and then you are done. You got to 60 fast but you wont make it to 70 kind of thing.

You will find endless threads here about combos. Start researching. You may want to check out headbytes porting on youtube for some edumacation too.

IROCZ1989

iTrader: (1)

Very doable with that budget. Im selling a longblock 383 now and may just part out the top end. Vortec stealth ram/ injectors and afr vortec heads. Any way you do it the intake is the choke point. As is the heads and cam. What do you want the car to do?

TPIVette

Check this out when you get a chance. Its a link to the build thread for my 383 TPI build. Although its in a Y-body, the similarities are obvious. It goes high 11s in the 1/4.

http://www.corvetteforum.com/forums/...o-results.html

DrvngCrooner

IROC, I wanna go fast!

But seriously, it has plenty of low end, but if I'm cruising along at 30-40 mph and gun it I'd like to feel myself being pushed back in the seat. Lot's of torque, not nearly enough hp.

sheikss

Are you dead set on keeping the tpi intake?

DrvngCrooner

TPIVette,

I checked out your build thread. Awesome job, I'd love to ask you some more detailed questions in the future when I reach that stage! Thanks!

DrvngCrooner

sheikss, I suppose I'm not "dead set"... I wonder how much must be replaced and tuned if I go away from TPI... what are you thinking?

DrvngCrooner

TPIVette, could I bother you for your $.02 on upgrades while the engine is in the car?

Abubaca

iTrader: (3)

I'm actually building a 383 TPI right now too.

Unfortunately, SOOooooo many parts/upgrades fall under the heading of "it'll help a little now" ....but will do a LOT more later when you add more parts! ...that being said, assuming you've got stock manifolds, i'd definitely go headers/exhaust all the way back.

The cool part about having a 383 is that any heads/cam/intake mods will help. ALL would be best, but that's a lot to take on without pulling the motor. I did it when I was about 30. Back won't let me do that at 40. Neither will my wife. lol.

Also keep in mind that deep gears might not be ideal for a TPI, but compared to the common 2.77 gears, a nice tall 3.27 (what I have now) is a LOT better, and still works well with a TPI. ...you can find the whole rear for a few hundred bucks and swap it in a few hours.

TylerSteez

iTrader: (3)

as others have said, you're going to be fighting the TPI's bottleneck all the way but I can totally respect ones desire to keep it. aftermarket TPI systems will definitely lower the bottleneck but they will eat up about 33% of your budget.

sheikss

Well, there a is another brand hsr knock off on ebay for $200 something. The biggest thing that will kill performance in that 383 is the tpi. How fast are you wanting to go? My little hotcam, miniram, 58mm tb, trickflow 195's, lt, 4" mufflex, 3200 stall, 3.73, 3800lb gta with less than 10 to 1 compresion 350 runs 12.3 in the 1/4 makes power past 6200 rpm and did 375 rwhp 350 rwtq. I have a crank and rods to stroke it. I figure that same combo on a 383 with some real compression would go 11.7 or 11.8, at a minimum, in my tank. Spend the money on good heads and a better intake. Watch the classifieds here and ebay to find deals once you decide what your goal is for the car. Oh, another awesome 383 combo is trickflow 195's, a efi single plane, and a gm 847 cam. I have seen that combo go low 11's all day long in a 3rd gen.

DrvngCrooner

Thank you guys very much, it's certainly no easy task - I greatly appreciate the advice!

LiquidBlue

Tpi not a bottle kneck. GM MSEE know what they r doing. Live it love it!

VincentZ28

iTrader: (2)

I say Miniram all the way. Check my sig.