t.p.

My lil' bro just bought an '85 Carrera coupe. He wants to upgrade the airflow meter to a mass air flow, change the chip, and add one of those cone filters. (He's already put a cat-bypass on.) Are these mods worthwhile?
His b-day's coming up, and I want to get him a chip. What's the scoop on all the different ones out there?

Peter Kelly

If he is going to do Mass air flow, then he needs to get the chip with the air flow meter. I have the autothority kit on my 89, and it dynos at 210 rear wheel HP, which translates to something around 245 engine HP, which to me was a worthwhile improvement over stoc (217 engine HP)

The difference is very noticable driver the car before and after the change.

Jgordon

Peter, did you put in a mass air flow as well? What other mods have you made?
And lastly, if you have made other mods, do you think it's worth getting a chip alone?

Thanks, I appreciate any advice you can offer.

Jared

Cary E

Here's where I'd go first ............

<a href="http://www.rennsportsystems.com/~porsche/" target="_blank">www.rennsportsystems.com/~porsche/</a>

They are not one size fits all.............

Tony'z911

Peter- I'd be interested in more info. on the kit that you have!
I have an Autothority chip, cat by-pass, and a bore-honed intake manifold for better and more even air flow. I believe I'm running around 225 hp w/ these mods although the engine is pretty old (135k miles) so it might only be good for pumping out 220. I've driven a stock '86 Carrear and I could definetly tell the difference in my car! Also- instructors are usually very impressed by how hard the car pulls down the straights at the track.
I'd like to think it's my great driving skill that rockets me out of the corners that much faster than the other guys and helps give my car the faster speed down the straights, but I'm sure the mods do most of the work.
-T

TC_SJ

The guy in Autothority said :

The kit (Mas Flow Sensor / High performance air filter / Chip) will gain at least 38HP and 42 ft torque,this kit cost aroubf $2000.

they also sell the High performance chip, this will gain about 16HP and 18 ft torque , cost only
$395

Have any one has this mod and truly got the gain as Autothoity claim

Thanks
TC_SJ

t.p.

i received an email from someone who researched all of the available chips (actually purchase all of them and ended up going to a custom programmed chip), and he said the autothority one is best. I think autothority now claims revisions to the chip making it good for 21 hp.

Peter Kelly

OK here are all the details on my engine mods:

- Autothority mass air kit with cone (not K&N) filter. Chip that came with autothority kit, slightly tweaked (by me)

- B & B cat bypass.

- GHL single outlet muffer.

- Magnacore wires

Thats it. Rest of the engine is bone stock. Car has 211 rear wheel HP (dynojet numbers) and it hauls *** compared to stock.

If you figure 15 % powertrain loss (it is probably more like 18 %) this gives engine HP of 248, which is 31 more than stock.

TC_SJ

So this statement from the Autothority Tech Ref is incorrect ????

The kit (Mas Flow Sensor / High performance air filter / Chip) will gain at least 38HP and 42 ft torque

I assume with cat by pass, B&B and GHL muffler.

Peter car will gain more than 40HP

Willie

Peter: What do you mean by "slightly tweaked by me"?

agent325

is there a signifacant power gain from only adding a chip?

Peter Kelly

Willie:

As received the chip had a rev limit of 7060 in it, which I think is too high for stock 3.2 rod bolts, so I hacked the ROM, turning it down to 6800.

Also as installed, the motor ran too rich (11.5:1 air fuel ratio) above 5500 RPM or so, so I leaned out that part of the full throttle map a little.

Re: chip only mods, I think the benefit would be small, maybe 15 hp.

As far as actual engine HP gains, you can't exactly correlate wheel HP from dynojet to engine HP on brake dyno cuz you don't know exact numbers for power train losses.

For example, 211 RWHP (rear wheel hp) at 15 % power train loss = 248 engine hp - 217 stock = 31 hp gain

OR,

211 RWHP (rear wheel hp) at 18 % power train loss = 257 engine hp - 217 stock = 40 hp gain.

So you see, this is all just a numbers game unless you take the engine out of the car, dyno it, make the mods, dyno it again. Then you will know true engine HP gain.

A good point of compare would be a dynojet run on a bone stock 87-89 3.2

One more point, peak HP is just a number and does not define how much faster your car will be on track. With the mods I made, I have higher peak torque and HP, but much more importantly, the HP curve at 85 % of peak is much wider than stock, as published in my owners manual.


The statement that the mass air flow gives you 38 hp on a 3.2 is in the ball park, probalby a little optimistic.

druck

Mass Air flow sensor conversion,cat tube, free flow muffler, high temp wires that conduct SLIGHTLY better spark and you think you're getting 40+ hp and 40+flbs am I getting this right? Please dont takes this the wrong way, but you guys are out of your minds. Marketing has really got all of you. Realize that the 3.6 with 11:1 compression twin plug, allowing substantially more agressive ignition curve gives you 250. Wake up guys stop wasting your money.
d.

Herb E.

t.p.-

See my post from 11-06-01 on 'Mass Air Performance'....I did the conversion and for the money was less than satisfied. I used a G-tech Pro, to measure HP differences, as well as my 'feel' driving the car. I put in the Authority chip and mass flow, and Dansk cat bypass + muffler. I did a phased comparison with the bypass/muffler first, then adding the MAF/chip later. My feeling is the MAF adds only 10-11 HPs (rear wheel) on top of a cat bypass/muffler upgrade which added 5-6 HPs. Some folks may have had better luck, but for my money, ....get a chip and maybe the exhaust upgrade and save yourself some cash.

Stephen Masraum

Don't bother with just a chip unless you are getting the chip to adjust for other more major mods to breathing in or out. It's a waste of money. Another thing, it seems Porsche got more aggressive with their mapping in '87, so the '84-86 cars will show a little improvement while the later cars will show less.
A chip properly matched to a better intake ("hotwire" MAF, manifold, etc...) and a better exhaust will do you some good, but a chip by itself is not going to do much for you except get your car that much closer to detonation territory on those hot days and/or times when you don't get good gas. Chips work the most magic on cars where the factory has been very conservative for various reasons (Porsche is not very conservative) or turbo charged motors where the comp controls the boost. Otherwise they are a good way to get your money.