350 tbi automatic, k&n open element, underrdrive pullies, dual exhaust with flowmaster, if i were to put on a msd or a dui distibutor coil and say a ignition box how much differnece would that make, would the old A$$ dyno be able to tell a difference? i am just curious because i finally figured out the ignition system is past do for maintenance/replacement and am going to be need to get either new oem or equivelant parts of aftermarket parts. thanks, chris
CK5
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ignition upgrade on 1993 chevy tbi
- Thread starter bad_bo_ti
- Start date
blazerguy 90
1/2 ton status
Ignition Upgrade
I have a 90 TBI chevy blazer, all the ignition parts are original, except for my plug wires, in the next week im going to order an accel ignition module and coil from Jeg`s, I don`t know if I will notice a gain or not, but considering all the stock ignition parts are original (15 yrs old), I would think there would be a small performance gain.
I have a 90 TBI chevy blazer, all the ignition parts are original, except for my plug wires, in the next week im going to order an accel ignition module and coil from Jeg`s, I don`t know if I will notice a gain or not, but considering all the stock ignition parts are original (15 yrs old), I would think there would be a small performance gain.
bagged beast
Registered Member
i have a 92 tbi 1 ton with headers intake cam nitrous and full exhaust and i just converted my to a hvc power coil and 6al box and it made a world of difference
Thunder
3/4 ton status
I have DUIs Coil and Dist Module, Accel cap and rotor, Taylor wires. The ign up grades made a small inprovement. Better throttle response. Also works better at high RPM than stock. Unless the stock Dist has bad bushings there is really no reason to replace it. They are good units.
Hard to tell if you notice anything or not. Things might be bad/marginal as is, no matter how much $$ you spend on replacement parts, the thing would run better obviously. Usually the case anyways with plugs and wires alone.
I'm not a believer of the aftermarket ignition setups in stock or mild build applications, but the module and coil can be "upgraded" for not much more than stock I'd bet, and can't hurt.
I'm not a believer of the aftermarket ignition setups in stock or mild build applications, but the module and coil can be "upgraded" for not much more than stock I'd bet, and can't hurt.
dirtwarrior17
Banned
Yeah thats true but while your getting a new one why not send another 50% more power to the plugs? I DEFINETLY need a new dist on my 88 because the points are all rusted out.... seems like this is pretty common. I tried to wire brush it after spraying it with wd40 but its too hard to get at. It runs fine for now but i no im gonna need one in the near future.
Because if the stock system can't be improved upon enough to make a difference, adding another component in that can fail and leave you stranded (or at least working on it in the dark/cold) and costs more money, there is no point in it.
If you can't ignite the mix (in a mild engine, yes some radical setups will have problems with stock ignition) with the 30,000 some volts the stock system puts out, 300,000 isn't going to help, you've got other problems.
If it was something you could see with a dyno, for the cost/complexity it might be worth it, but there is a reason you don't see before/after dyno tests from the aftermarket ignition makers. Just lots of claims about multi-spark and amazing voltage numbers.
Of course, you WILL see comparisons in magazines (rarely) and the ones I've seen have indicated less than a couple HP compared to a USED, unknown condition ignition system baseline.
one of my racing buddies told me it would not make a noticeable difference. the reason i am thinking of replacing the whole distributor is because of some corrosion starting on it, i figure i will do plugs wires and a new coil and a new complete distibutor or just a cap.
Most of the time, the corrosion I have seen comes right off with a bit of steel wool or fine sandpaper, depending on where it is. The HEI systems really seem to be "resilient". Had bad weights and springs (sticking badly) in my distributor, thought for sure I'd pick up some serious power and economy, and noticed nothing when I got them working right.
Heck, as long as the cap and rotor terminals are clean, not cracked, the terminals are still tight, and nothing is actually missing pieces from corrosion, those can be cleaned and reused as well. They are easy to inspect, unlike plugs and wires which can have flaws that you just can't see. I can state with certainty that new vs. used on cap/rotor made NO difference in performance in my truck or car, numerous occasions. At least not enough to notice in MPG, (or feel, but thats wholly inaccurate) which I closely monitor.
Check the endplay and bushing on the distributor. Good learning experience anyways. Nothing wrong with stock, they just are well designed. From experience though, it pays to look at these while you are digging into everything, they CAN have problems.
To me replacing a cap or rotor just because is like replacing a steering wheel because its old...you can see the whole thing, if it needs replacing, you'll see the problem, and thats the time to replace it. Coil is the same to me...thought I had a bad coil, but replaced the wires first, and the arcing (visible and audible) I thought was a coil problem disappeared.
Heck, as long as the cap and rotor terminals are clean, not cracked, the terminals are still tight, and nothing is actually missing pieces from corrosion, those can be cleaned and reused as well. They are easy to inspect, unlike plugs and wires which can have flaws that you just can't see. I can state with certainty that new vs. used on cap/rotor made NO difference in performance in my truck or car, numerous occasions. At least not enough to notice in MPG, (or feel, but thats wholly inaccurate) which I closely monitor.
Check the endplay and bushing on the distributor. Good learning experience anyways. Nothing wrong with stock, they just are well designed. From experience though, it pays to look at these while you are digging into everything, they CAN have problems.
To me replacing a cap or rotor just because is like replacing a steering wheel because its old...you can see the whole thing, if it needs replacing, you'll see the problem, and thats the time to replace it. Coil is the same to me...thought I had a bad coil, but replaced the wires first, and the arcing (visible and audible) I thought was a coil problem disappeared.
thanks for the advice, i think i will replace the cap for know because i can see the metal points on the under side are worn quite a bit. coil i will leave alone and i will just clean the distributor up for now. i have my eye on some stainless headers and a modified throttle body i can blow the rest of my money one!!!!! 
Good call. There are a lot of things you can spend money on that will net you some serious gains compared to ignition. 
Hey Bagged Beast,
Wow your mods sound awsome, how much Nitrous are you running, let me guess a 175 shot. No No it has to be more with that hopped up ignition. Man it must be nice to have all of those SWEET parts and such a well designed rig to put them on. I read your profile, how does the dual transmission setup hold up to offroad abuse.
Wow your mods sound awsome, how much Nitrous are you running, let me guess a 175 shot. No No it has to be more with that hopped up ignition. Man it must be nice to have all of those SWEET parts and such a well designed rig to put them on. I read your profile, how does the dual transmission setup hold up to offroad abuse.
dirtwarrior17
Banned
a new stock dist. is only 75 bucks less than a good aftermarket one...yeah it doesn't add hp but its one less thing to worry about and it will most likely be a little more responsive all over the power band. Peak hp is something you wont see a difference in but peak hp is not why people put good ignitions on.
I don't know any of this for fact but i remeber hearing this alot.
I don't know any of this for fact but i remeber hearing this alot.
Stock distributors have a LONG life to them, I'd not suggest buying a new one unless the original is just worn the heck out mechanically and not repairable.
Regardless of peak HP, if the ignition system contributed "under the curve" it would still show up on a dyno, no?
Regardless of peak HP, if the ignition system contributed "under the curve" it would still show up on a dyno, no?
dirtwarrior17
Banned
I really have no clue about the under curve but responsivness doesn't always mean hp does it?
bought a cap and rotor tonight and threw it on, seems alot better now. actually had to break the rotor to get it off 
i was wanting to wait and do it after i get my aldl cable and hook it up to the laptop and see if i could tell a before and after on it. but i couldnt wait. thanks for the advice.
i was wanting to wait and do it after i get my aldl cable and hook it up to the laptop and see if i could tell a before and after on it. but i couldnt wait. thanks for the advice.
I don't know about the responsiveness part. Better idle could be seen with a tach, thats simple, but it stands to reason that if you gain MPG on an engine with a mod (nothing that affects weight or aerodynamics, solely engine) then the engine is producing more power for the same amount of fuel.
As an extreme example, an engine that is misfiring because the plug wires are shot would make worse power on a dyno than one that wasn't misfiring...if you ask me, that would be a definite increase in responsiveness (having driven vehicles that are misfiring) and thus something quantitative on a dyno or with other methods.
I'm not so far into engine dynamics though. I guess I can see an engine revving up faster, but producing no more power, just not sure how that is possible short of changing how fast the throttle is pressed. When you start getting into timing and all, that is something that can be seen in HP/TQ numbers, so...
As an extreme example, an engine that is misfiring because the plug wires are shot would make worse power on a dyno than one that wasn't misfiring...if you ask me, that would be a definite increase in responsiveness (having driven vehicles that are misfiring) and thus something quantitative on a dyno or with other methods.
I'm not so far into engine dynamics though. I guess I can see an engine revving up faster, but producing no more power, just not sure how that is possible short of changing how fast the throttle is pressed.
When you start getting into timing and all, that is something that can be seen in HP/TQ numbers, so...
