Are stock runners worth messing with?
 

as the title says, are they worth it or should I go with something else? I'm looking to get close to 330-350 crank HP so I'm not sure if switching the base or plenum is in the near future, just wondering about the runners since they're a huge problem with tpi. ATM I've got an 86 tpi system that's going to be swapped onto an 86 tpi motor that currently has a tbi.

also, is 330 crank hp too much to ask from a light setup (crane 2032 cam, port and polish work to both the intake and heads, full 3" exhaust with 1 5/8" headers, roller rockers, and custom chip) or will I have to do more?

Re: Are stock runners worth messing with?
 

You could port the plenum, but IIRC, the runners and baseplate are the main problems with stock TPI airflow. If you're doing the work yourself, then it might be worth messing around w/stock runners. Otherwise, I'd look into aftermarket upgrades, such as Edelbrock or SLP. Besides, if you wanna go even further with your power goals, you'll get even better results from modding aftermarket runners as opposed to stock!

Restrictive intake flow is the main thing choking the stock TPI, so I would imagine with both improved intake and exhaust stuff (stock exhaust manifolds are CRAP! Headers help alot), as well as head/cam work, that 330-350 crank HP should be a fairly easy goal to achieve. This is of course assuming you're working w/a 350, not sure about a 305.

Have you installed subframe connectors in your car? If not, it's a good idea to help these car's unibody design to support real power

Re: Are stock runners worth messing with?
 

yup I'm working with a 350. the exhaust is one of the first things I'm going to change out completely, I've heard that alone makes a huge difference. subframe connectors and posi (yes, its open right now :/) are in the plans as well.

I was looking into slp runners not too long ago but I remember reading a thread that the inside diameter of slp runners are actually smaller than stock. I might change the base as well if it will help me get to where I want to be, mainly just wondering if the stock tpi is capable of making that much power.

Re: Are stock runners worth messing with?
 

I'm not sure about the SLP runners, but I remember reading that the Edelbrock runners are some of the better flowing ones out there. There are some other ones out there too, but they can be a bit trickier to hunt down.

Are you asking if the stock TPI can make that much power with other mods like exhaust and internal engine stuff? Truthfully, I'll answer that I don't know. But the way I see it, heads and cam work wont help you to their full potential without doing all the exhuast and intake work first to help maximize the engine's ability to breath.

I pretty much have the same plans as you with my car/engine (lots of body work/paint/tlc needed badly first though), and I have exhaust, headers, runners, and baseplate in mind before any other engine mods. Those mods alone should make a huge difference in top end. Even with 305's, these mods can help quite a bit.

One thing to keep in mind though. You can get a TPI to flow pretty well for some nice mid-range grunt with mods, but by nature, they'll always excel at low end torque best, due to the long runner length. Check out the TPI shoot-out thread, it should be stickied. They used a built 383 in the tests, but it'll give you a good idea of how stock and modded TPI systems compare to other options.

Re: Are stock runners worth messing with?
 

yeah, I might end up swapping the base and runners then. I really want to try to keep it as stock looking as a can so ill have to look a little bit.

mine doesn't need took much work. its an 89 formula in the baby blue. the drivers side door can be repaired but its almost not worth it when I can pick one up for $100 and it needs a patch piece on the drivers rear fender. couple little rust spots on the hatch but other than that, its clean.

well thanks for the help

Re: Are stock runners worth messing with?
 

going with aftermarket base and runners won't be cheap, ~650.00 or so new. and the plenum will still need some port work.
if you want to keep the stock appearance, you may want to look into the FIRST intake. it starts where the other aftermarket intakes end at after porting them.
but its not cheap either, starting at $1000.00 for a base, runners, plenum, throttle body, and injector rails. plus you still need to setup the fuel lines to it, throttle cable, and get a fuel pressure regulator.
some people have had problems with the FIRST throttle body, but for most it works fine.

Re: Are stock runners worth messing with?
 

well hell, I might as well just get the stock to work as well as I can and switch to a stealth ram or mini ram later on.

Re: Are stock runners worth messing with?
 

If your muffler/tailpipes are original and in good shape, I may be interested in buying them when you swap out. PM me.

Re: Are stock runners worth messing with?
 

Don't even waste your time on the stock TPI intake. With just an intake and headers these engines are completely different creatures. Also you'll want 1 3/4" headers for a 350. 1 5/8's are more tuned for a 305.

I would say some 1.6 self aligning roller rockers, SR intake, and some 1 3/4 headers will put you pretty close to 300hp. Also don't neglect a decent tune up and compression check. Make sure you are starting from a healthy engine.

Where did you get 330hp from anyway? I assume you're just trying to 1 up a stock LS1? You will have a fun car cheaply with the mod's I suggested.

Re: Are stock runners worth messing with?
 

to my knowledge they're original and in very good shape

youtube.com/watch?v=cpbWiEzZvpg

Re: Are stock runners worth messing with?
 

Thanks anyway, that's an aftermarket replacement. :)

Re: Are stock runners worth messing with?
 

something like that. I wanted to get close to 350 but I figure a little less would be a more reasonable goal. ill definitely look into a stealth ram. might just use the stock intake until I can get the money together for one since I already have it sitting in my garage

Re: Are stock runners worth messing with?
 

ah, I really wasn't sure. just got the car a few months ago and not too familiar with 3rd gene yet. sorry

Re: Are stock runners worth messing with?
 

The stock top end can support 400hp, so don't be in too big of a hurry to start swapping stuff out, unless your looking for the "cheap & easy" route of upgrades.

Re: Are stock runners worth messing with?
 

I don't want it to be too pricey but I'm not afraid to spend a bit extra if it means it'll make a huge difference. exhaust, intake, cam, and tune are what I'm trying to limit myself to since I've got a few other projects to work on

Re: Are stock runners worth messing with?
 

Quite possible IMO... figure 330hp is 270-280 at the tires based on what bolt on LT1 guys do. They are 300 stock and can do 250-260whp and some bolt ons usually gets near 280's with automatics. Some less.

My full bolt on L98 made 254whp running lean... so thats 300-310hp at crank give or take. Mild cam should net 15hp more, maybe 20. So you are in the 270 range.

Re: Are stock runners worth messing with?
 

any idea where to find that l98? was it here in the forums?