Hey guys, I'm pricing out mods to do but I can only do 1 out of the mods I'm thinking of...

No matter which I choose, I'll see a significant gain on my car, but the hard part is choosing which gives the best hp per dollar ratio.

Here they are:

1)Holley 670 TBI for 5.0 L

Pro: More air/fuel flow... no more starving at high rpm. Possible access into the 5000 RPM range, possible 20 HP boost. Easy to install.

O2 screams lean lean lean at WOT on my car. BS factor taken into consideration, without BS factor supposed to be like 40 HP yeah right...

Cons: Expensive piece, probably will have to get shipped from states, looking at almost $600...

2) Edelbrock Performer RPM TBI w/ EGR

Pros: Definite access into 5500 RPM range, fuel/air needed is another matter. Medium install factor, give me 2 days tops for this, 1 for messing up, 2nd for fixing the mess up.

Cons: Although cheaper than the Holley, it still comes from the states for sure, and the 2 days carless factor hurt in case I manage to f up royally and need a car. Also, with the fuel/air bottleneck that is the stock TBI, may end up performing the same.

3)Hooker shorty headers with air and y-pipe

Pros: Frees up the major bottleneck that is the exhaust. Difficulty !@#$!@$#@!. Yes I think that job ranks up there in difficulty... Probably will end up having a shop do it. Cost anywhere up to $700... and that's not taking into account I want it to get a decent paint or ceramic coating...

Cons: Damn expensive, can't do myself really...

4)Comp extreme energy cam or LT1 cam

Pros: 1000x better than peanut cam, cheap, medium to hard difficulty $100-300 possibly... most gain from this mod...

Cons: Manifold has to come off as well as 2 bolts on oil pan in order to take of timing cover so engine has to be lifted, have bad memories from my last lift.. busted distributor cap... bolt from hell xmember tranny and all the wonderful bolts there... get the idea.. I have nightmares from working in the block...

5) Ignition system

Pros: I'm going complete here, control box, coil, wires, cap, rotor, billet, plugs... Probably cheaper than the holley lol... Definite gain via the more flatter torque curve this will make, better combustion at higher rpm, not to mention easy starts... Easiest to upgrade I think... Jacobs is out of the pocket book range, but MSD makes things affordable and reliable hehe. Possible $500 altogether...

Cons: Nothing really unless you consider changing plugs and wires a walk in the park, even then this is a first time job so anxiety factor is up there.

6) Sell car as 100% fully functional blueprinted no smoking car with virtually nothing to repair save paint which I'd do before selling... heck it even has 100% working AC and only bad thing is cosmetic interior... engine doesn't burn any oil.. will still get 95% of the oil back (all black and nasty mind you) that you put in at an last oil change... WOT runs great... corvette servo... 3.23 gears... a great modders car...

CON: This is the last thing I'd do and I love my car and I'd rather slit my wrists before doing that lol... I blueprinted the car myself. Compression at 9.5:1 when cold... I put heart and soul into it...

so anyways, I'm kinda pressing the ppl with ignition systems since that may be what I choose to do due to budget and knowledge of electronics and my car...

 

Gee so many mods to choose from.Well I would have to say that if you can only do one, then it should be either the headers or the ignition system. The intake, cam and TBI are all part and parcel of each other. I already have a Holley carb, so an intake will be right inline as to were I want to go.
There is another option you have that you didn't mention... 1.6 rockers. It will give you more HP, they say about 10-15 more horse. I don't know if that is including the BS factor.
Tha ignition system will provide a little difference, but I don't know if it will be something that you will notice, headers on the other hand, they say will create more horse power and your car will sound better. You have some tough choices. It makes you wish that money did grow on trees.

 

I agree with Kevin here...I think the headers would be a good start. The cam is a great idea, but then you might as well get the 1.6 rockers and better valve springs and yada yada...kinda opening a can of worms. If you're thinking of doing the cam, I say hold off and save a bit more money to do the whole top end. Ignition is a good mod if your existing system is do for replacement, but don't go outta your way to do it as you will see very little in the way of performance.

 

do the headers! if you do the cam it will end up turning into one thing after another. you will end up needing to do or wanting to do a lot of other things wile you are in teh engine. and in the long run will cost you even more money.

the headers will also help improve the sound too

also dont forget that the lt1 cam is roller. is your engine roler now?

i would go with header if it was me

 

Yeah.. I know the intake/cam is the can of worms job.... anything that makes me get into the block will end up forcing me to upgrade the rest in the block... so that's a con for all those inner mods... chain modding lol...

Rockers would be a good upgrade, but considering that with the current setup, I may not even see a gain from them real world. Let alone BS factor gains...

I'm kinda been leaning towards the header or ignition mod... see here's the thing, in 2nd gear assume forced TCC lockup via switch, less load on engine than 3rd, so less fuel air needed to get it to rev up requiring less spark and engine will pull hard till 5500 then it does the struggling/surging feeling and tops off at 6000 rpm... surging may be exhaust related, not flowing out enough... but the fact remains it keeps pulling a lot higher... has enough fuel/air/spark... Take 3rd gear... significant load increase, need more fuel/air/spark... pulls till 3500 dies at 4000... significantly restricted... not sure if there is enough spark to ignite the fuel/air.. or even if there is enough fuel/air at this load level...

Now here's some indications... no matter what load level 2400 RPM is max torque. This is more a cam/flow restriction limitation than anything... In 2nd 3rd 4th almost always same limit. The thing is I'm pretty sure the torque curve is flatter in 2nd vs 3rd since it can pull a lot higher in the rpm. The mile per rpm gain is less due to gearing therefore the same max hp is produced as in 3rd, but the rpm levels is significantly different.

The dilemma is, do I need more fuel/air in 3rd or do I have enough but the ignition system isn't capable of igniting that amount of fuel? This is where one of those data acquisition computers that only retail for like $1000 us would help a lot in...

I'm gonna do equation work over the next few days to see if I'm air/fuel restricted or spark restricted up to 5k rpm... I know at 5500 I'm exhaust restricted for sure..., but what about lower rpms... I target 4500 rpm as my short term goal so I gotta figure out which is the main restriction, air flow/fuel/spark or exhaust...


Palric.. I got a q, in which order did you create that 13.9 TBI beast? I know I'm pressing hard here, but did the 670 give you access into the 5k range in 3rd gear? Was it the headers? Did ignition do it? I'm aiming more for a hp per dollar mod at the moment...


Thanks for all the input, its much appreciated...

 

I'd lean towards exhaust as well. As long as your ignition system is in good working order, the stock stuff should work well enough at those rpms. An upgraded system wouldn't hurt, but I think bigger gains will be had with the exhaust. Only downside is that if you know you are running lean, you'll be worse off than before with the headers.

 

the headers would definetly make a big difference, but i also found that when i swapped in a nice Crane Enegizer cam and lifter setup and an Edelbrock Performer intake it made a world of difference. it really woke up the engine. granted i have a carbed 84 LG4 with no computer or emissions, so i didnt have to get expensive emissions and computer compatable parts. and as you and Irocker and others have mentioned, once you get the blocked opened up you are gonna wanna do other stuff as well. by the way i also have headers.....i have a set of flowtech shorty headers as well as MSD HEI stuff (module, coil, cap, rotor)

 

Hey Brad, have you dynoed the car? I would love to know horsepower you are putting out. I have plans to do the same with my LG4, when the money permits.I will be installing my intake this week and I already have a Holley carb and K&N filters. I will also be getting a Trans Go shiftkit installed sometime this summer.

 

For the price your gonna pay for your headers, i would do the intake and the cam. You'll notice more of a difference from that than the headers, for less or equal the money value. And you shouldn't have to pay anyone to do it, they're both straight forward.

 

Do you have a flowmaster muffler only or the whole cat back?

I would start here if not. I saw about 3 10ths in the quarter with flowmaster system only on an almost stock 86 TPI IROC. I have the single exit version..sounds grrreatwith a little more flow! I used MAC headers after and it made almost NO difference. They were not hard at all to put on, slipped right in from underneath..mind you none of the AIR pump stuff went back on.
I'm sure one of the guys here can give you or sell for cheap a set of original TPI cast exhaust manifolds, thet are larger than what you have now, try that first if you're afraid of headers.
I also did a cam without dropping the pan, was a bitch to get the timing cover out, just trim the corners on the inside of the front seal groove a little to get it back in. Was minor gains..puller higher up top. Get a kit and do the springs at the same time. Easy to do without pulling heads.

 

Kev...i have not dynoed my car. i would love to know how much power (or lack there of) it is making, but dyno time costs a fair amount, even when there is a group going together. unfortunately my LG4 has the good olde 8.6:1 compression ratio and crappy stock heads and that certainly does not help things in the power department. however, by 87 i think Gm had upped the compression ratio on the LG4 to something around 9.5:1. check in your owners manual, it will likely say. do you still have the stock cam in your LG4? if so i would say throw a nice cam and lifters in there while you are putting the intake in. the Crane Enegizer kit i got was around $185 i believe. it came with the cam, lifters, and break-in lube.

 

from all the engine mods I've ever done to cars, an intake and cam combo will wake any engine up, more than headers. I know where you can get a set of Flowtech's for $149CAN it includes Y pipe. So, those won't break your pocket book either.

There's no point putting an aftermarket throttle body on the stock restrictive intake, the gains will be unoticed for sure.

I'd seriously put on a good intake and a nice cam, if you can do this yourself, you'll save labour and even be able to get yourself a decent set of headers.

If your interested just shoot me a PM.

 

Brad, if you want to dyno it let me know, as we will be doing the Dyno Day again by the end of the summer. Save up a few bucks (it cost about $63 last time with 8 cars). We had time to do more, so I will try and get about 9-10 cars this time. Everything went really smooth. You get the car on and they run it for you. If you want to make some small changes, you can do this and then they will run it again. They give you a graph of the runs so that you can compare. Besides you will get a chance to meet and greet the members that come out.
I would like to do the cam and lifters, but time is an issue. I can't have the car off the road for any extended time. It will have to wait, I guess.
Hey Cruz, where are these headers you are talking about?$149.00 CDN with the y-pipe.Are they painted, coated,used or new? Let me know...

 

Is it me or he said the magic number? $149 sounds really good and has y pipe... Where can I get these from? Odds are I will go that route if it only cost that much. I'm not gonna do them myself, I've already had a nasty experience with thirdgen headers and not aiming to repeat history. also the air tubes must go back in, I still have 6 years/3 tests of emissions to go.

The Holley should give a good boost, 480 cfm stock rochester vs 670 cfm holley will help a lot. Also, no worries about being fuel starved if I go that route.

Ignition system is in good working order...

Actually the whole car in general is in top form right now from a stock perspective. No leaks, no smoke, no oil loss, pulling stock numbers from the rear wheel instead of the flywheel. Its quite a car. Hell it has working AC even just to top it off.

That's the thing, you know if it ain't broke don't fix it. For the first time, I'm not worried about anything breaking because I've personally gone over each and every part over the last 2 years. Aside from the panel rust spots, its amazing.

I know that in its stock form, everything upgraded will give a noticble boost dyno wise. I'm just fighting with myself over what I can do for this summer.

If I can get my hands on a cheap set of GOOD headers, I'd probably go that route since that log they call headers are tiny pos.

My other but more expensive mod is the 670 TBI, give it a good intake or exhaust fix first before messing with the inside guts.

The intake and cam, springs, rockers etc I'll save for a 1 shot deal when I got the spare change. I can't just do a cam or just an intake when I'm in there...

The ignition system lies as the median upgrade, not much if any boost, but a sound investment nonetheless, just like the 670 tbi and the headers. Its not as much for the hp, but for the base that the hp will be built on. that's why I went into my block and changed rings. I wanted a good base to work with and blowby was not a desirable thing to have when putting together any motor.

So down to 3

670 TBI

Headers

Ignition (Complete, box, coil, wires, rotor, cap etc...)

All input welcome and appreciated.

 

$149 sounds almost to good to be true. I really shopped around for my flowtechs and the best i could find was $160 for just the headers, plus another $140 for the y-pipe.

You can't even get them as a set from Summit or Jegs for much under $200 US if i remember correctly.

Anyways, if you can get them for $149 for the set, I'd say jump all over them because your not going to find a set of new headers any cheaper than that.

 

Just about everything has been said. My 2 cents...
Go for a cheaper set of headers and maybe some other mod. Except for the ignition, all the other mods will make that bottleneck worse.
They may not wake the engine up a whole lot, but
once the headers are on, you can dump all the fuel/air in you want, without trapping it in the engine.
The fuel/air mods will help alot, but you'll never get the full potential without the headers. If your putting it in there, you have to get it out.

 

that was my reasoning before.. nothing will do any good as long as the logs stay in there... If the headers are cheap I'll do them the min the heatwave dies off...

 

We returned a set of Hooker full lengths that were $400 and some bucks. And had a credit, when Luke at Total Race found these flowtechs. They included the y-pipe and we paid $149. The only downside is they're only 1 1/2 primaries which I think is fine especially for a TBI application or an street engine. And my set didn't come with AIR tubes, I specifically asked for no air tubes. They come with the normal black paint that burns off in 10 seconds. but if you sand all of the paint off and use high temp "barbecue paint" in the barbecue section, then bake them in the barbecue, they turn out a nice satin black and they haven't changed color since.

Alot cheaper then $700, and you have $550 to do other stuff as you please. Can you spell nitrous kit?

 

My '88 Formula with TBI had alot of work done to it over 2 1/2 years. My credit card bill was pretty scary. But the car broke 13s in spite of everything it had going against it -- low output options galore....

I had a stick so my TBI rev'd ok to begin with I think 5200 was max when I bought it. I'll try to remember the order I did stuff in.

- installed 3 inch cat back with flowmaster muffler. Very noticeable mod in fact I'd say having a proper exhaust put under a 305 is one of the better bangs for your buck with each mod it just makes the entire package better. More on that later.

- got rid of the Gators and installed Comp TA ZRs now called KDW. Big traction gain and stopped heading for the ditch every time it rained.

- installed a dual snorkel intake from an L69 '84 Z28.

- installed/adapted an '84 T/A cowl induction piece.

- installed an ACCEL coil. Threw it out a week later.

- installed an MSD coil. Threw it out a week later.

- installed the Holley 670cfm unit with two 80 lb'ers. I can't remember exactly but I think it was a direct bolt-in to the TBI manifold. They claimed 15-20hp gains and I never disputed it, it easily added 500rpm to the top end all by itself. Should have gone with the 70lbs I didn't know any better back then.

- installed a Jacobs ignition system (Mileage Master) one of the best bangs for the buck that I have done (current system notwithstanding but you know the story on it). Made th car run like it is on steroids.

- installed Comp Cams roller tip rockers and hardened pushrods. Gave the engine a noticeable bite at about 2500rpm.

- blew up my rear and installed a 3.42 posi swapped from drum to disk at the same time. I originally tried a 3.73 and loved it but it made no sense for my commute so went with the 3.42. Factory was 3.08 so anything was an improvement.

- swapped out the TBI manifold for a Weiand dual plane. It worked ok on bottom but I liked to rev so took it off and installed a single plane unit (7525 ?) and this was the ticket this combo of manifold and TBI loved to rev and I think that was the first I saw 6000 rpms ?

- installed Hedman headers with custom Y-pipe, hi-flow cat and replaced everything with Mandrel bend pipe. That was a costly adventure but to this day I can remember the sound that exhaust made and how well it worked. I'll do it to my TPI car eventually.

- installed a 217/225 .480/.505 cam. Way too freaking much intake duration on the cam I had 11 inches at idle which drove the MAP insane and the car never idle right afterwards. I installed Comp Cams conical valve springs my lift was around .505/.525 at that time.

At this point I was hitting the track (Mission Raceway, Mission, B.C.) more often and finding low 14s. I don't remember 60 foot times but I don't think they weren't really impressive. The engine tended to come on at around 2500rpm and rev'd clear to 6400rpm. It made power above 6k and tended to go flat around 6500rpm.

During this time abut after the cam swap, the car ran like crap with a whole series of Ed Wright chips circa 1994. I spent alot of money trying to get a chip to work the new cam but just had a whole lot of frustration and less thena desired results at the track. Eventually I threw them out in disgust and put the factory chip back in and guess what ? I pulled a 13.96 on my next run. Go figure. The car still idled like crap but atleast it did not do that sickening surging above 4000 rpms. If only I had DIY ECM capabilities back then ! To this day I think that setup had more to give just need proper tuning but wasn't up to it.

The perf upgrade also costed me a tranny and my 305s bottom end. The T5 did not like being power shifted at that kind of rpm and the bottom end started to knock with about 10k on the new cam. I couldn't keep my foot out of it -- it was too much fun to watch the tach bouncing around 6500 so I blew up the drivetrain.

There are more mods that I haven't listed. I forget all the stuff I did to that car.

RP.