$500 for a dyno tune?

[87blackroxi]

I stopped by a local speed shop on my lunch break today and asked how much it would be to tune the car and he told me it would be $500 :ugh . I almost S#!@ myself. Is this about how much a dyno tune costs? They said basically they retune/program the car. I work with people that swear by this place. What do y'all think? Is this worth it. Or am I better off going with a custom chip?

 

[bill81vette]

the fellow that is redoing the body on my 81,just put a dyno in this winter. he told me that he is charging $ 150.00 for three runs on the dyno..a lot of the drag race people from Lebanon Valley Dragway have already booked time witrh him b4 the season starts so they can get there cars ready to race...I plan on having it done after it is finished so I know where the engine is at for HP...

 

[bossvette]

Yes thats about right, Dyno time is $100 an Hour they will weld in a O2 sensor for the dyno's wide band(much more sensitive) O2 sensor and tune it over a period of a few days once they have the main fuel map correct they begin to work on the start up and enrichment curves. the start up can only be done when the car is dead cold so they usually let the car sit over night.
Unless you have major mods it would not be worth the money unless gas prices go so high that the fuel savings would pay for it.
Bring it to cruise-fest dyno day instead if you just want to see what you have

 

[87blackroxi]

Well, the major problem I am having is after i replaced the spark plugs (they were in really bad shape), the wires, distributor cap & rotor, fuel filter, and added the headers the car is having trouble idling at a stop while in gear. Everyone has told me, even the speedshop I went to for the $500 quote on tuning, that it takes a while for the ecm to learn the best economy for the car. But they said it can only relearn so much. The dyno tune supposedly goes above and beyond what the stock limits of the ecm are. So i pose the original question, Is $500 a good price. and is it more worthwhile than a custom chip?

 

[74bigblock]

You don't have enough done to your car to warrant a custom tune. You should have enough miles on it by the end of the week for it to have re-learned any changes due to an upgraded ignition and exhaust. I wouldn't go spend $500 on that until you rule out everything else.

Are you throwing any codes? What did you gap the plugs at?

 

[87blackroxi]

Well, I don't have a computer/programmer to check codes yet. But, the check engine light hasn't come on. The plugs were already gapped at factory recommended. The major problem is the idle. I will wait a week or so and see if there's any improvement.

So the custom tune isn't necessary yet? What about a custom chip?

 

[89vert]

Correct me if I'm wrong but I thought I read you had an idle problem before the headers and tune-up. If I am correct it could be the IAC is dirty and needs cleaning. For a cheap test run some injector cleaner thru the gas tank and see if that helps your idle. Seafoam thru the gas tank is probably the best bet. How is it idling now, rough idle or is it hunting?

 

[vetteboy86]

I doubt that the ecm is still trying to learn. Learn what, just from new plugs and wires. I think there is something more going on. What RPM does your car idle at?

 

[Vettefan87]

Yeah, what Craig and others said. When I swapped out the thermo master chip for the stock one the car idlled funny for about 5 seconds, then it was fine. I doubt the ECM takes that long to relearn itself. I wonder if you ran two bottles of Chevron with Techron with a full tank of good 93 octane gas if that wouldn't help any?

 

[Jeb]

If you didn't check the gap on those plugs, that's where I would start. All it takes is a little bump and that "factory" gap setting is history. PLUS, I doubt if they gapped them specifically for your installation, unless the stock L98 is the only engine they fit.

Take a moment and pull a couple of them and check the gap. I'd almost bet you'll find they're off a tad, maybe even more.

 

[vetteboy86]

Yeah, you have to gap the plugs. They usually write the gap on the boxes, when I buy them and then I gap them. Also two bottles of chevron techron will make the car run even better.

 

[SurfnSun]

FWIW I spent alot more than $500 on my dyno tune, but in the end it was worth it.

 

[74bigblock]

If you didnt check gap before install, I'd do that now. I just did my plugs and out of the box the gap ranged from 30 to 48!!!

 

[Mad-Mic]

thats about the same mods i have on mine 87 and i use the stock chip. i recently been having idling problems and cold start problems but i thought it was from a few codes popping up. no more codes but still same rough start but runs great now even when cold. idle is still alittle rough but i think that is because the car is now breathing better. i've had my mods for a year as it sits now and it has idles alittle more lumpy than it was when she was stock but then again i don't have mufflers and i feel the car now. a tune would smooth it out and will give you about 20 more rhwp but is 500 bucks worth it? there are chip tuners on this forum and another forum that can tune it for you if you get your shop to data log some info for them. i personally think my idle and cold start problems are from a dirty TB and the IAC is still alittle dirty. i didn't have any carb cleaner when ECSS (Tom) came over sunday and helped me with the codes. i think that will help the last remaining issues. gonna do a few more mods then back to the dyno myself before i start my tear down

upto you which way you wanna go but for dyno time it's usually 100-150 bucks for 1 hour or 3 pulls with A/F ratio printout. this don't include tuning.

 

[87blackroxi]

This weekend I put the carb cleaner in and it didn't make much of a difference in the idle. The car still hunts with the idle. I will try to pull the plugs out and check the gap on them tonight or tomorrow. Also Do you think cleaning the tb and iac? is something I should consider?

 

[74bigblock]

This weekend I put the carb cleaner in and it didn't make much of a difference in the idle. The car still hunts with the idle. I will try to pull the plugs out and check the gap on them tonight or tomorrow. Also Do you think cleaning the tb and iac? is something I should consider?

Couldn't hurt to clean them up... but I doubt it is the issue. My bets are on one of those plugs being gapped goofy. It doesnt take much at all to get them out of gap (just having them sit on their end in the box can close them up a bit more. ... and who knows where they have been before you bought them!

 

[larry bud]

These things idle like crap. I've had an 86 since 1992, and it idles properly about 1/3 of the time. It's just a terrible design.

 

[black_81_vette]

if its been doing this before plugs and ect,were installed there can be a few possabilities.First check the coil output you need a fat juicy spark to light a lean mixture to begin with.Two make tripple sure the intake gasket or runner gaskets are not leaking.3 if you still have the cold start injector hooked up they have been known to leak and cause all kinds of hell.Hope this helps and good luck

 

[black_81_vette]

Oh and one more thing check the wires make sure the firing order is right I put one on wrong once and chased my tail all day LOL!

 

[bossvette]

I had a problem with my idle once what had happened was the stop for the Throttle had bent over time which would not let the throttle butterfly open enough which in turn meant the IAC was open all the way and was not doing its job. Once I bent the tab and reset the base idle (I have aftermarket controller) it was fine. Do clean the throttlebody and IAC it will help.