Is there a chip for a 305 tbi? If there is? What kind of horsepower gains would I see?

 

yes there is. Hypertech has one. You have to buy a colder thermostate and fan switch for it. when all is done you gain anywhere up to 15hp or so. you can find it on summitracing.com

 

i got a 305 tbi. is it worth getting and will you feel any difference?

 

I have a '91 Caprice wagon with a 305 and got a chip for it from tbichips.com .

It gave me a substantial increase in the drivability of the car, which was the main thing I was after. With the stock chip the motor would feel strong on initial tip in but for about the next 1/4 throttle would feel like I was transformed back into my sisters old Pinto 4 cyl. station wagon.

The modded chip improved this substantially, the car is much nicer to drive. It also feels like it has more top end power. Not a ton, but enough to notice.

With the chip I have you have to run 91 octane and swap to a lower temp thermostat or it will knock.

After buying the chip I decided to get into chip programming so I will eventually be replacing it with a home grown one, but this chip was worth it, the car was a drag to drive with the stock chip. This is a California smog car, so it may be that I saw more improvement because of that, from what I understand the stock chip on the Cal cars is different.

Paul T.

 

there is also a website called tbichips.com they are way better than hypertech and they have a crap load of usefull info on the site

 

Ya, tbichips.com is where i will be getting mine from when I get it

 

I would not buy into EITHER one. Read the stickies here and learn how to burn your own. There is a plethora of information more here than on tbichips.com. IMO, its about the worse thing you could do to your car (mail order tuning in general). Think of it this way. Would you send your carb to someone to fine tune? I know I wouldn't.

 

I would if I didn't know how to tune it myself.

 

They are way overpriced and give you a seat of the pants feeling of extra power because he throws in extra timing to make it feel snappier, which is not necessarily a good thing.

Also, remember, when you say there's a lot of info on the tbichips site, he got ALL of his information from THIRDGEN.ORG he came here, learned how to tune his own chips and made a profit off others' knowledge. Keep that in mind.

 

It's sad really, but as PT Barnum said "There's a sucker born everyday" or somthin like that.

 

Extra fuel AND extra timing in my experience. The timing tends to make the engine responsive and the fuel covers the detonation. The vehicle would be MUCH faster with the correct timing and fuel. His tunes are a good way to make alot of noise and go no-where as well as knock the ring lands off the pistons.

 

I will let you guys know what I think when the chip gets here and I will have my mechanic take a thorough look on what exactly the chip does.

 

In case you didn't notice, the people here are already very familiar with his work. You won't be showing them anything they don't already know. Your chip will be inadequate, you can count on that. Unless your mechanic is well versed in TBI tuning he won't tell you anything you can't learn here, especially from a few of the people that have posted in this thread. I know, it sounds tempting, an off the shelf high performance chip custom built for you hot rodded TBI motor.

Fast355's point about not sending out a chip like not sending out a carburetor is that without the car attatched to it, it can't be properly tuned to the application. One can only guess in that situation. It has to be done first hand to be done properly. Otherwise you are wasting time and money. If you can find someone locally that can tune it in person (and maybe even on a dyno) that would at least be better than sending it out.

 

FWIW, I got a chip from Brian at TBIchips.com. I argued with the fine gents on this forum that it was going to be exactly what I needed for my daily driver 305.

I took it to a dyno shortly after installing it. The results were maybe another 5HP but my economy took a dump. The fuel/air measurement showed I was throwing twice the fuel I needed to into my intake. The only real benefit I saw was that the speed limiter was removed meaning I got to go over 115mph when I wanted (like never). I started wondering what the change in the fuel tables was doing to my engine's life span.

I removed it the following week.

I don't recommend this to anyone unless you get datalog to Brian and have him burn a customer chip for you. That wouldn't be the cookie cutter PROM.

Just sayin',

~C

 

The chip shouldn't be any harder on gas, I told him I wanted gas mileage to be the same, he said I should see a little improvement, but I will see when It gets here, what it does for me, then I will pass it on.

 

Quote: With the chip I have you have to run 91 octane and swap to a lower temp thermostat or it will knock.

this cant be right? I run a 180 therm and 89 octane in my car with 10.0/1 compression with no knock in logs. In fact I could run 87 octane if I wanted to. just run a diff spark table.

 

Yeah, the commercial chip went too far with advance, and I'm going to redo it, both the spark advance and the fueling. However the commercial chip was a step forward over the original chip and it was worth it as a first step. It will be a while before I can steal the time (I've got a business, a nagging ex-wife, and kids always late on their homework to deal with) to do a chip from scratch and in the mean time the car drives much better with the commercial chip, the stock chip made the car a pain to drive. With only a 305 in a big wagon the poor throttle response of the stock chip really sucked.

I haven't noticed any change in mileage with the commercial chip, the car actually gets better mileage than I expected, better than my '94 350 pickup.

Paul T.