I see where Zip has a chip for an 81. My question is "does this work"? I believe on fuel injected but on a carburetors? How much control does the ECM have? Can I run my vet in the "tuner class"

 

It's is the same BS as the 82 aftermarket chips, what you get is full advance on the timing when you go WOT. other than that it is mostly hype.

You still might get a little benefit from it, but don't expect a miracle.

If you dead set on tuning, you could try asking on the Prominator board if they (Bill) has anything that will work on the 81 for you.
http://prominator.homeip.net/

And I don't think adding a chip will boot you into the tuner class.....

 

True, Dd; he'll need to add stickers to join the tuner class. Seriously, the recalibrated chip is most effective when the thermostat is changed to a 160* or 180* unit. Unfortunately, 160* on a street car is too cool and can trigger the '81's choke, making it run richer. The 180* is a better choice. And premium gas is recommended. IMHO, I'd save my money for other mods, like neon....

 

Everything hear about adding one of these is bad. Basically, you won't notice any difference other than the increased acceleration your Vette has due to the weight saved by the reduced money in your wallet.

As part of the RPO L81 (horsepower delete option) club, I'm always on the hunt for miracles. I even went to their homepage to read up on the stats hoping for some good news. Here's what THEY say

1. Won't work with K&N filters
2. Won't work with dual exhaust

You want bang for your buck? Bigger cam, K&N filter, dual exhaust and tune the carb!

Afterall, It's all about suck and blow!

STW!

Platato

 

Well said Plat, but it could be worse. Try driving an old, tired out LG4 some time.

I agree with DD, though there probably is some small benefit to be had, though I doubt enough that you'd notice. From what I've read the timing advance helps a little and the chip is faster to go to full rich. I've heard some about the temperature changes that Master spoke of but never seen it documented.

IMHO, you'd probably notice a bigger change in power by switching to Mobil 1. Besides, if you don't put the new chip in just right, you'll get to stare a thte "check engine" light for the rest of your life.

 

I hear you all. Thanks for clearing the myth.

Platato, I had the "California 80" also. Now I have an 81. I didn't notice much difference in the two. Although the 81 was power starved also. Did find the 350 to be more parts friendly than the 305.

Thanks ALL!

 

Myth? I'm not so sure. I reckon that fitting the chip on its own won't give any noticable improvement. I'd fitted dual exhausts & a few other doo-dads & my '81 was a lot better than it was when it was stock. Then I fitted a new cam & the mid-range improved a bit, the top end may have (I couldn't tell as the stock ex manfolds were strangling it) but the bottom end felt like it had lost power. A lot I advanced the initial timing (WELL WORTH DOING on an '81) & it was better, but I was still feeling a bit disappointed with the new cam (& Performer intake that went on at the same time). I then saw a forum member was selling a Hypertech chip for an '81 auto so I bought it. On fitting, it took about 1/2 mile for me to completely disregard everything I'd seen on this forum regarding Hypercrap chips. The difference in low end performance was much better & performance off idle was about the same as it was with the original cam (which gave good power at about 2000rpm). I'm glad that I'd fitted it. As I said, sticking it in without any other mods done won't give much, if any, improvement, just as their website said when I looked at it.
I'd say ignore people who've fitted one with no other mods, or those that have just read up on it & formed a negative opinion. Get impressions from people who've fitted one after doing a few other mods. If you've not got any other mods done then don't waste your money on one.
Whether you've got the stock system, or a modified system, it pays to advance the base timing from 6*BTDC to something up to a max of 13*BTDC (depending on local fuel quality). I've set mine at 11*BTDC & the off idle response was markedly improved (and it doesn't cost anything to do!).
DO NOT fit a 160 stat in an '81 with an ECU still controlling the plot. You'll very likely get into a situation where the computer keeps going in & out of closed loop due to not thinking that the engine has warmed up enough. It'll lose bags of power (not good with only 190 available ) & guzzle fuel. It'll also be a pig to drive. A far better stat rating is 180. This is a good compromise between getting power & keeping the engine hot enough for good lube, etc. If you've got an auto & fit a 180 stat then you may find that the TCC stops locking up. Mine quit working for no apparent reason & I now suspect that it was because the ECU didn't think the engine was hot enough to give lockup. I could easily be wrong here as I never found what the problem was (fitted an OD trans instead!), but if you fit a 180 stat then it's something to check afterwards.
As far as I know the Hypertech chip controls the A/F mix differently by going full rich on the primaries at different times. I'm not sure if the ign adv goes to full adv sooner, but I think the advance curve is maybe more aggressive. I think it also controls TCC lockup differently (I wouldn't know - mine isn't controlled by it!).
I would stake a years supply of beer on the fact that the Hypertech chip gave my Vette an improvement at the low & mid rev range. That's a fact (I'd be really pi$$ed if it hadn't because I would have felt ripped off by fitting a cam that lost me that much power at the bottom end just to give a little bit more higher up). I don't think the chip did much at the top end as there's not much it can do. The A/F is supplied by mechanical secondaries (the primaries are set on full rich by both stock & Hypertech chips) & the timing is fully advanced when the revs are high. If the Hypertech chip advances the timing slightly more than stock then you can simulate the same condition by advancing the base timing to get the same full advance (which will also shift the advance curve up correspondingly - a good thing unless pinging occurs).
While you make your mind up (& people type replies to shoot me down in flames ), get out there and advance your base timing a few degrees. Best free mod you can do.
The stock computer system, if set up correctly, is good unless you use a cam that causes low manifold vacuum.
K&N filters are overrated. I use one but that's only coz I can just wash it rather than seeing I need a new filter & having to order one from a specialist here or in the US (& because they come with lots of stickers that I can put all over the car ). For the same money you can get a decent set of plug leads, or spend a bit more & get a high voltage coil (something else that improved throttle responce on mine. I fitted the coil & leads together & the engine was much more "crisp" afterwards. Whether it was due to the {insert marketing hype here} high voltage spark, or because my old coil/leads were clapped out I don't know, but replacing 24 year old leads & coil is a better bet than fitting an expensive filter that gives very minor gains over a stock filter IN GOOD CONDITION. Something I find strange is people fitting a K&N (or other) filter in the interests of gaining power, but then remove the cold air intake so that it's sucking hot air in from the engine bay. What's all that about?
The mods I've done to mine, while not being many or radical, have really woken it up (best was dual pipes). I once had a stop light drag when behind an '80 & I had to stamp on the brake to avoid running up his ****. That was when I had the stock th350c in there so both cars were matched on gearing. Mine still has the "junk" computer controlling it so, reading some people's posts on the computer control, what went wrong? I should have been 100yards behind him with the Check Engine light flashing at me & an engine coughing & spluttering.
If you want to fit a cam with lots of overlap then chuck the computer system in the bin as it won't handle it. If the cam gives a good manifold vacuum at idle then the computer system gives you closed loop operation when running on the primaries, just like modern cars do, with efficient A/F ratios, & when at or close to WOT it just sets the primary mixture to rich & lets the mechanical secondaries control the overall mixture. You've got a merger of old world carburation & more modern closed loop, allowing for good economy & throttle response when running on the primaries (the majority of the time when street driving) & have the option of changing secondary rods/hangers as normal when tuning for modifications (eg Headers). The timing can be viewed as a complex electronic ignition system.

 

I put a Hyper Chip in my 81 and here is the results at the Drag Strip...
Without the Hyper Chip 16.943 81.28 MPH
With the Hyper Chip 16.583 83.26 MPH
So draw your own Conclusions But I think it was a bit of a Improvement..
Just my 2 cents.

 

I conclude our '81s are still slow, chip or no chip

 

You want power? Ditch the computer, ditch the smog stuff, ditch the Cat, and go true dual exhaust. Noticeable difference right away. By doing this you must get a new carb, and distrib. Which, if original, you probably need anyway. Don't forget a new higher flow intake manifold.

I'm doing all of this right now.......wish I had dyno'd before to make a comparison. But I had a serious turtle. Put the new distrib. in this weekend just to play with it, and it was an awesome difference. Whole system should be in this week!

Future mods (to add power):
Electric fans
New heads and headers
New cam

Want power?


Drop CAt
Pipe in true dual exhaust
Drop computer and smog
New distrib.
New carb.
New intake
Electr. fans

Then if still not happy:

Headers (I'm probably going to do this one)
Heads
Cam

 

The Hypertech chip made a noticable difference in my '81. I don't know how much difference it would make in a stock engine, but mine's not stock. It's a crate engine with 9.2:1 compression and TFS aluminum heads, rated at 330 hp. Changing the chip made a nice difference right away.

The chip gives me an advance curve that is what the modified engine needs. And it's not just full advance at WOT or high rpm. You get more advance much earlier in the curve, and the increase in throttle response tells me I'm getting more advance at part throttle.

I had the problem that was mentioned above, where I used the 160 stat as recommended by Hypertech, but the engine controls would never settle down. The choke kept cycling. But switching to a 180 took care of that.

I wouldn't argue that there may be better ways to spend the money, but if you already done the heads, cam, etc., on the '81, then you need to recurve the ignition to get the full benefit of the mods. And with the '81 computer, a new chip is the only way to do that. There may be other chips that would be a better fit to the specific mods. I feel like this chip is a compromise, between a minor improvement on a stock L81 and a much bigger improvement on a modified motor, so a custom chip to match my mods would probably be better, but I don't know where to get one.

 

Or, even cheaper, ditch the EFE & EGR, fit true duals & remove the cat &, for high end power, fit some Headers. Just fitting dual pipes & dumping the smog controls will give a major improvement in performance. Whether you've got a stock HEI or an aftermarket one, the max advance possible will be the same, so adjusting the stock system to give that max will reap some extra power. It won't be all in early on, but this could be where the Hypertech chip comes into play (depending what the advance curve looks like). What I'm saying is that a lot of mods can be done that will live happily with the stock computer. There's a few past & present forum members that run cams, heads, etc for more power & have still kept the computer. One beauty of the computer is that the Check Engine light comes on to tell you that's there's something wrong, no matter how minor. A lot of the time it's warning of things that most people wouldn't notice. Where the computer falls down is when 160 stats are fitted (& I'm not sure how they really are a good thing for a street driven car) or when significant gains in power are being sought.
Personally, my computer system has flagged up a small vaccum leak that I would never have found if it didn't force me to keep looking. I had no idea there was a problem, but it wouldn't stop nagging. Eventually I found a tiny hole left by whoever removed the EGR system & fixing it made off idle running a little bit better. It wasn't bad with the leak, but it wasn't perfect. My point is that I could have checked all the pipes & not found a leak, ripped out the computer system, bought a new carb & distributer & spent my time on the forum saying "The computer system is rubbish, all it ever did was flash the Check Engine light for no reason". If there's a problem in the system that's expensive to fix then chuck it all away. But if there's an inexpensive problem it'd be crazy spending a whole lot more cash on the assumption that the system is just junk & you're better off without it.
Out of all the mods I've done I'd say that the chip would be the last on the list (excluding the roller tipped rockers) for you to notice any gain.

 

Why wouldn't you recommend getting the opinion from both groups (with mods, and without mods). Seems both camps have something to contribute...


BTW I was basing my opinion on the chip upgrade based on the 82's. I'm sorry it wasn't the correct answer, but at the time it I was the only one to resurrect this thread for him...

 

I figured that if I'd put the chip in mine with no other mods done then I'd be unimpressed with spending $130 for minimal difference & my answer to the post would be "Spend your money on something else, the chip is a waste of money". 2 - 3 years back, when I was looking at buying one, the forum had a lot of posts saying things like "Hypercrap", "Ripoff", "POS", etc, etc & it put me off buying one. When I saw a used one going cheap I thought I'd give it a try & got completely different results to what I'd seen posted, so I'm trying to balance out the arguement by saying that it's worth fitting but it'd be more effective spending the cash on other mods beforehand (a cam & lifters aren't much more) & then using one to complement them.

I'm not having a pop at you as you've said what I would have said if I hadn't done some other mods first. I think, from reading past posts, that your answer is the right one as the chip in a stock setup doesn't give the performance improvements promised. Hence me saying ignore posts from people that have few modifications, as they'll discourage anybody from getting the chip (the posts I used to read were so adamant that the chip is junk that I thought it was nothing more than 5% of minor tweaks to the algorithms & 95% marketing hype).
If you've not done it already, try advancing the base timing. It was a great free mod on my '81 & combined with the Hypertech chip it made the throttle response really nice with a quicker pick-up & a rorty exhaust note

 

I have the chip, it's not in my vette yet. I just haven't gotten around to putting it in. I bought it on Ebay years and years ago. I'd love to read the data on it and see what it is doing and how. Then I could make my own chips. Anyone have a PROM reader?

 

Me to, but I'm one of the dying breed of assembler programmers who spends all week reading/writing EPROMs & I can't face doing even more!
Yes. I was planning on taking a dump of the PROM as a backup at some point (in case it ever gets zapped) so could forward you the hex dump if you want. Won't be doing it for at least a couple of months though as the Vette is locked away for the winter.
One day, if I ever get any spare time, I plan to take a dump of the chip & the stock one & compare the two, just to see how much of a difference there is. It could be interesting, but after 26 years years of 0's & 1's my enthusiasm for it is summed up by the expression on the face of that bloke in your avatar

 

I hear ya, I've been knoodling around with different flavors of UNIX over the past 20 years trying to make a living and the last thing I want to do when I come home is bang out code and try and work on computers. Seems fitting I have the first year of the CCC.

 

Nail on the head Sometimes I think I'd rather spend the evening pulling my own teeth than looking at more software. But you try telling that to the kids of today & they don't believe you (apologies to Monty Python or whoever's sketch I've just murdered)
Ditto. Ironic really, I finally got a C3 after a 20 year wait & what did I find in it? A PCB with a processor, a PROM & everything! Even the edge connectors looked familiar. It was like being at work, I couldn't believe my luck