Basic tuning explanation?

[Racing944s]

Hi.
I have a 1984 944 I'm looking to tune. I know very little, but have good tech knowledge. WHERE do I get good solid basic tuning info to helpme get started? I'm interested in using a free program such as TunerPro/TunerPro RT.
I want to learn how to tune: be it a 944, CRX, InTegra or the like.
If anyone knows of some good material or would like to give an explanation, I would definately appreciate it. :-)

Matthew

[guru944]

Visit link:

DIY 944NA DME Tuning w/ TunerPro.

Pretty clear

Later.

[Racing944s]

Thanks!
This is good stuff.
Where I'm at in my tuning knowledge, I need a bit simpler form. Meaning, step by step thru what everything does. I'm aware and some what fimilar with the sensors and such, but need someone to explain what does what, and why. Also, where to go when a certain thing starts to happen; where to start with the whole process, can I raise the rev limit from say 6500, to 7? Haha, the simple stuff. This is something I'm very interested in ad nwant a solid base so when I got to tune my 944, I really what I'm doing.

All that said, is there materials out there like this, or do I need to find someone with knowledge like this and learn from them?

Thanks alot guru944.

Matthew

[flash968]

do you have about 10 years?

tuning an engine is not a simple task - while the actual steps are fairly simple, knowing what you are seeing and getting and then knowing what to do about it is a much more involved process - you can easily do a lot more harm than good

the writers of these programs assume that you already know what everything in the engine and control systems do and how they do it - they also assume that you have already got an idea of what you want the engine to do, and what is needed to get there

get some books on engine tuning - read - then go to the internet and get more - read more - read the shop manual

then, when you finally have a grasp of how things work, assume you are going to ruin your engine, and start playing

[guru944]

Matt;

A good book I recommend/came across years ago:

"How To Tune and Modify Engine Management Systems" ISBN 0-7603-1582-5 Motorbooks international (motorbooks.com) list for $29.95.

I use it for from time to time. Great source for beginners and intermediate tuners alike.

PM me when you get a chance. Grace and peace brother.

[hpaulb]

I get the feeling he's not talking about modifying the programing but rather just doing the simple things like done on a regular vehicle. These cars are almost completely self controled. Simple things like wear on the spark plugs, replace. Air filter, oil change. That's about it.

[flash968]

he said he wanted to use TunerPro, which is for the computer tuning - that is what led us to the recommendation to start with reading

[krystar]

yea basics of tuning should start with reading and understanding 4 stroke engine cycle. until recently, all u could adjust is cam timing, ignition timing and fuel. now with modern ecu's, there's variable lift systems and cam phasing systems, it gets alot more in depth.

and that's just NA engines. turbo's are whole another book.

[Racing944s]

Yeah, I mean like tuning with a computer. The stock HP for the NA 944 is like 147. I'd like to see that at about 170 on a dyno. Is this possible to gain that much from a stock setup? I saw pics of a graph of sorts from a tuning program; how do you make sense of it all?!

I'll check that book out.

I eventually want to build a 944 track car and race it here in VA and WV and surrounding areas.

[krystar]

crank horsepower may be rated at 147, but even original factort power measured at the wheel would have about 15% loss, so 125whp or so. asking for 170whp is a 36% increase in power. which frankly without forced induction or completely reworking the engine, just isn't going to happen.

[flash968]

i think the thing to remember and stay focused on here is that there is no short cut - tuning is not a simple matter, and not for the beginner

a lot of reading should be done before venturing into this area - a clear understanding that you are lucky to get a 10% increase in power from all tuning and bolt on components combined is definitely in order - to expect more than that without major modification is not realistic

[HondaDustR]

Exactly. The thing is, Porsche did alot of the homework, so it's not a matter of just throwing on a better intake or a bigger exhaust pipe. Everything, I mean every bit and piece on these motors is tuned to work together, so changing one or two things won't get much. That's not to say it can't be made better, it's just that it has to be done together and in the right balance to be productive, and then you'll only see maybe another 20 or 25hp max at the crank putting work into an early spec motor, and that's artificially large, since you can gain about 10-12hp just by going to the higher compression factory pistons from a '87 motor. I like tweeking easy things here and there to gain more power, too, but it's just already done on these. There have been a few very nice race motors built over the years that push a bit past the stock '87 spec 162hp, but the work required is very involved and consequently expensive. There are hotter cams out there (another one of my slight complaints with the stock 2.5L), and even a pretty cool programmable ignition controller that interfaces with a Ford distributorless ignition system that can be found cheap at any good wrecking yard (http://www.autosportlabs.com/ there is one user that had done alot of work with the megajolt on his 944), but stuff like that won't make alot of difference unless tuned to work together.

Here's a little secret you can share with your less educated car buddies...max dyno numbers are cool and all, but the real achievement is "area under the curve". Torque, being instantaneous twisting force at the crank, is kind of a gage of how efficiently the motor runs at a given speed, which alot of things affect, but fuel and ignition advance profiles have an especially large effect on. Horsepower is just another way of saying work per unit time, which you can increase by increasing the speed at which the same torque is able to be delivered, or by increasing the amount of torque produced at a given speed. Clever tuning can do both, and these motors respond well to it because Porsche tuned the part throttle fuel/ignition maps fairly conservatively so it could pass emissions standards in the US. The stock chip is downright boring compared to a good dyno tuned chip like the 944MAX. Max hp does not increase more than 1 or 2, to as much as 5 with a more open exhaust, but the torque increases as much as 10-12 ft-lb in the low end. Throttle response and overal engine character improve dramatically. It won't make it much faster off the line, but it will be much more fun to drive. There are a few good threads on custom tuning projects where people had very good results.

Now if you want something with a bit more attitude, the 16 valve 2.5L used in the 944S is naturally a much more rev happy motor with about 30 more hp to boot, and it will drop right in to any 944. That's still my dream setup right now, still retaining much of the torque and the character of the big 2.5 but with a little more of the raw "bat out of hell" kind of experience only a good built B18 type R motor can deliver. There's also always the most popular advice here...spend the money on suspension upgrades and good tires. You thought the 944 handles good now, well it's just the tip of the iceberg. Good luck with it!