How Critical Is A Dyno Tune After Top End Swap?

[Gunmonkey]

I'm putting a Trick Flow Street Burner HCI kit, 24# injectors & corresponding mass air, and MSD box in my 93 notch. Car has approx 125K miles, and runs clean and strong. It already has full exhaust, 3.55s, silencer removed, K&N filter, adjustable fuel regulator, and bigger fuel pump.

I've gotten the following conflicting info as to post-install tuning: A) it MUST be dyno tuned with a chip; B) it SHOULD work fine as long as timing is correct, but a dyno tune will definitely maximize the potential; C) dyno tune is a waste of money for relatively mild upgrades like this, and that the computer will adjust to the new combo on it's own.

Any clarification as to what's really necessary would be appreciated!

 

[A5literMan]

(B)...it will work fine with that mild combo. But to clean up the idle and maximize performance I would have it tuned. The tfs 1 cam can be slightly temperamental at idle i.e. Slight surge etc. Will the car run without a tune? Yep. Will it run better with one? Yep.

 

[mikestang63]

It depends. If you have an AOD then more than likely you will need a tune. Stick cars are not as tempermental. If you have an adjustable FPR and A/F gauge you can tune it yourself to a decent level and see how it drives. As Todd said, that's a pretty common build that should net around 275-300rwhp. I'm not a fan of 24# injectors- IMO they are too much for a stock setup but almost not enough for an H/CI setup. I normally go with 30# injectors so you are not maxing out the duty cycle on the injectors and also have some room to grow in HP.

That being said, most cars will benefit from a custom tune to help with overall driveability and increased performance. You can have them map out custom fuel and timing trims,. raise rev limiters, disable CEL codes if EGR or other emissions devices are removed, and even run E fans when you wire the proper pins on the EEC. A good dyno tune and chip will set you back anywhere from $300-700 depending on how much dyno time is needed. I would recommend a local tuner over a mail order- avoid BAMA tunes whatever you do.

 

[Gunmonkey]

Thanks for the info, guys. That makes a lot of sense. There's a tuner local to me, and he recommended a Diablosport, but it seems the foxbody unit has been discontinued, and I haven't seen a used one in the classifieds or on eBay. I'm waiting to hear back from him as to what good alternatives might be. If you have any recommendations, I'm all ears.

My car is a 5 spd, by the way.

 

[A5literMan]

Thanks for the info, guys. That makes a lot of sense. There's a tuner local to me, and he recommended a Diablosport, but it seems the foxbody unit has been discontinued, and I haven't seen a used one in the classifieds or on eBay. I'm waiting to hear back from him as to what good alternatives might be. If you have any recommendations, I'm all ears.

My car is a 5 spd, by the way.

Most tuners use a SCT chip. You can look into a megasquirt system. We even have a thread on here with downloadable tunes and Steve seems to know his chit on fine tuning it. You would actually be tuning it yourself and with that knowledge you shouldn't ever have to pay another tuner going forward with any build "upgrades". Long term it's a very feasible option. Good luck!

 

[Gunmonkey]

Great info. Thanks very much!

 

[a91what]

If interested in the MS system or want to see any info on it/see one in action, visit our help thread.

You can even download the tuning software and data log software for free! This will allow you to download our tunes and data logs and view them, check it out before you buy anything and see if it's for you.

http://www.stangnet.com/mustang-forums/threads/steves-megasquirt-tunerstudio-help-thread.888730/

 

[Gunmonkey]

Thanks all!

 

[stykthyn]

With the ease of stand alone software Im really shying away from dyno tuning for basic set ups.
10 years ago this stuff was difficult at best to muddle through, but now there's enough internet support that we can self tune in our garages for a little less than cost of a dyno session.

 

[Black1987]

With the ease of stand alone software Im really shying away from dyno tuning for basic set ups.
10 years ago this stuff was difficult at best to muddle through, but now there's enough internet support that we can self tune in our garages for a little less than cost of a dyno session.

Especially when you can buy these for on the fly tuning.

 

[a91what]

Especially when you can buy these for on the fly tuning.

On the fly tuning can be done anytime really. I just use my wb and (injector duty cycle vs map*rpm) scatter plots tuned correctly it should look like a straight line.

 

[bird_dog0347]

I just did basically what you're talking like 6 weeks ago... The idle and driveability sucked with the stock MAF and injectors so instead of buying the MAF, injectors, chip, and a tune which would have run me close to $1k I bought the MegaSquirt unit for $835ish and it fired right up with the base tune and ran even better than before. Now I get to play with it and get it closer and closer on my own, and when/if I go bigger on the mods and want a dyno tune I don't need a chip, they can just use what I have.

 

[Gunmonkey]

Thanks Bird Dog. I already have the injectors and calibrated MAF. I'm starting the install tomorrow, and I'll see how it goes in that configuration. I'll likely be looking for a tuning unit regardless, as I want to be able to fine tune it for best performance and drivability.