I am interested in putting a performance chip into my 1990 convertible/automatic.
There are many companies that offer them my question is which the best one is and who I should purchase it from. I know that the members of this forum can help me sort the good and the bad and give me the best option for my car the first time.
Thank you for your input.

 

Honestly, save your money....Really...If you want a performance chip, datalog, then have a tuner do a custom tune for you..WW

 

What WW7 said.

 

PCMforLess

 

I've tuned many cars and I've had the opportunity to see first hand dyno and track results of many of the "off the shelf" chips. I have NEVER seen a mass produced chip produce any increase in dyno horsepower or decrease in track times.

If your car is stone stock and you get a "custom" tune for it you MIGHT be able to pick up 2-5hp, but probably not. GM did a really good job getting the most out of them from the factory.

Now if you've modified your engine with different heads, cam, headers, etc, etc, then a custom tune is absolutely essential for getting the most out of it. Again, don't waste your money on an off the shelf chip, they were designed for stock cars, they can no more take advantage of your modifications than your factory chip can.

I once had a guy tell me that "I can put a chip in that little 305 and it'll make it run like your 350." I just smiled and kept walking.

 

Unless you have significant mods, no point to it. And never a need for an off the shelf "tune".

 

Coincidently, I have a 1990 L98 Automatic Coupe that has a Hypertech 120382 Power Chip. Its the ThermoMaster Power Chip that is designed to be used with a 160 or 180 PowerStat thermostat. I also have the Powerstat thermostat (1018) but I am not sure whether its a 160 or 180. To complete the Hypertech stuff, I am also running a Hypertech coil. The only other mods are a Walker Exhaust system (3 1/2 inch pipes). Now here is the good and bad from my perspective:
The Good: All this stuff cost the previous owner over $1000 plus installation. The Walker mufflers sound awesome. Marginal gas mileage increase (about 1.5 MPG) compared to my 1991 L98. Don't know why the increase so it could be the chip. Having all this performance stuff on the car adds to the perception that this is a "hot rod" Vette versus a stock one. As I did not pay extra for the performance parts, that is fine with me.
The Bad: Walkers, like most aftermarket exhaust systems, generate a drone sound inside the car. I have Dynamated the rear compartment and that helped -- a second coat of Dynamat is going to be installed in the Spring. My tach is erratic (way high). Some say it could be the coil although Hypertech says that is not an issue with its coils. More than likely, like other 90s, its the tach intself which is also coming out for repair this Spring.

The bottom line is that the Hypertech chip hasn't caused any problems. The 1990/1991 Vettes were "plug and play" computers so I guess that its hard to screw them up with this PROM. If the previous owner had spent a grand on new injectors instead of the Hypertech stuff and mufflers, he would still be driving the car. That tells you something. Maybe its better to put that $1000 aside in case something bad happens.

 

I have a 1990 Vert auto also.Had the performance chip and all it did was to fail the emissions test. You cant really do much of anything to a 19-91 stock as this is the dreaded "SPEED DENSITY" set up and not the MAF system of previous years. You would need a great tuner who knows his stuff with the speed density system. About the only thing you can do is throw in a set of rear gears and even that will cause some minor emissions problems. Went from 2.73's to 3.54's and they are great SOTP feel.Had to change back to a basically stock exhaust system also due to emissions here in Ontario,Canada. Very strict testing here.
Bill

 

Couple of things. You may want to check on that thermostat. The general idea being that 160 actually allows the car to run too cold, thereby increasing wear.

Now for the scary one. I've pulled the program off of one of those chips for a 93. I did a complete comparison with the factory program and found 2 differences. 1, the fan temps were adjusted for a lower thermostat. 2, the rev limiter was set to 10,000 RPMs! Theoretically never a problem, but the first time your automatic transmission fails to shift properly and you're not paying attention, bye bye motor! This isn't a huge deal on a TPI because they really don't rev all that quickly above the shift point, they just don't have the air. An LT1 on the other hand will scream past the rev limiter quite quickly.

If it were me, I'd put a factory thermostat back in it, and sell the hypertech chip on e-bay. Somebody will buy it!

 

My 1990 passed emissions testing here in Virginia. Actually, it fared pretty well. I attributed that to new injectors and EGR valve as my 1991 had real trouble passing emissions until multiple injectors went haywire (shorted thanks to the ethanol in our gas) and forced me to replace them all.

 

What's wrong with speed density?

 

I'm also wondering that.

 

This is old school cheating stuff I used to do before tuning became widespread.
With the stock chip in, stuff in a 160-180 T-stat, drop the fan on-off temps, bump the base timing to 8-12 degs and raise fuel psi to 48-51with vac line hooked up. Run 93octane.
Years ago I was at the track, a guy with a whole bunch of stuff done to his vette (tpis level 5 prom) was running and was mad that his car wouldnt go faster with his high dollar chip. I gave him these tips and he picked up around 7tenths in the quarter mile. He did have quite a few mods also. I've picked up 3-4 tenths on a stockish car.
Tuning has come a long way since the old days sooo I recomend a custom tune.

 

I still have the PO's receipt for the thermostat so I will check with the vendor he bought it from (the receipt has their part number on it). For what its worth, the heat works great in the car. Warms up quickly but that probably would be true with either thermostat. I would not mind losing the Hypertech chip and coil. Replacing the coil is not a problem. However, I am not sure how to go about purchasing a used OEM chip. Are all the 1990s the same? Does it matter if its from a auto or stick? Can I use a 1991 EPROM if I located one. Are there numbers on the chip I should be looking for? If I did find one, what do you believe would be a reasonable price?

 

I just got off the phone with Summit Racing (where the PO bought the thermostat). They said that the Hypertech thermostat in my Vette -- the HYP-1018 -- is a 180 degree thermostat. The part number for the 160 degree thermostat is HYP-1000.

 

The MAF sensor adjusts for air intake...exhaust etc. and works well for adjusting and add ons. I had a 1988 Formula 350 Firebird for 19 years and did a lot of changes and had no problems with emissions. So when I got the 1990 Vette; I tried the same tweaks...big time problems with emissions. When I researched why; it seems that SDensity does not adjust to changes like MAF. It runs from predetermined calabrations from the MAP and MAT sensors for example and cannot tell the change in air intake flow or relocating the MAT sensor to a cooler area.. Once I changed back to near stock; I passed E-test.Im retired and do not want to chase the extra horsepower any more...just want to cruise. You need a tuner who knows his stuff to tweak SD proms. This is just my personal experience with MAF and SD.
Bill

 

It does take a little more time to tune a speed density car but it's a very proven system.

 

I just got a performance chip for my 2009 corvette form a company called powertune on amazon. I was not expecting much when I bought it and it's just ok, no crazy increase in HP but it does give it more pep. If you want a little more kick then I'd recommend it but don't expect to gain a ton of hp. The company also put together reviews on their site from customers. Some just talking about it and some doing 0-60 tests with and without it. powertune performance chip review