RAD951

be able to use autothority stage 2 chips with an aftermarket bigger turbo? Or is there a turbo that you can buy that will work with the autothority stage 2 chips with a 3 bar fuel regulator. My runs perfectly between lean and rich. But if I would add a turbo, the mixture would become lean. Can I compansate for that with more fuel by using a 3 bar fuel regulator or an AFR?

I know if I were to replace my k26 with a k27, my autothority stage 2 would not work because I would run lean on high rpms, and if I were to use it with a 3 bar fuel regulator, I would run rich at low rpms and good on high. So my question is, is there a turbo that will run more cfm of air through out the rpm band instead of just high rpms like the k27/6 ?????

Doc

RAD,

Good question, I wish I knew the answer, have you considered calling Autothority?

Frankly, I'm glad you asked the question since I was just about to do the same thing and hadn't even considered the issue of chip compatability.

Keep us posted, I'd sure like to know the answer.

ken louie

Doc and Rad I know that Autothority does make chips for the k27's. I currently have one in my car w/ APE MAF. I believe windward sell these chips however I have not been to their site recently.

Ken Louie

86 951
79 930

p.s. some people were call them stage III chips

Doc

So Ken, does that mean I would have to replace my existing Autothority Stage II chips AND do they only work with the K27 and not a Garrett?

What about the MAF, is that necessary too?

I'd rather buy new chips that pay for an MAF.

951and944S

Doc and Rad

You can keep your chips, get either turbo, just get a fuel controller like the ARC2 or the one Lindsey has along with a mixture (air/fuel) ratio display or gauge.

ARC2 is available from:

<a href="http://www.speedforceracing.com" target="_blank">Speed Force Racing</a> or <a href="http://www.huntleyracing.com" target="_blank">Huntley Racing</a>

other mixture control:

<a href="http://www.lindseyracing.com" target="_blank">Lindsey</a>

All three have air/fuel meters

Cheers

ken louie

Doc I believe you can just run chips and not get the maf. when I put my system together I had installed both the maf and k27 at the same time. I am sure you can run the garrett with out any problems with the k-27 chips. The problem I see is worth it just to buy chips. When for that kind of money you can purchase a piggy back system and be able to really fine tune your car.

Ken
86 951
79 930

RAD951

Thanks for the replies. The reason why I really asked this questions was because, I didn't want to change the chips on my car once again. I called autothority, and they a said k27 chips would run me $500 minus a $200 trade-in if I give them my stage 2 chips. I just wanted to see if I could save me $300, by using my stage 2 chips with turbo upgrade.

Thats why I was asking if there is a turbo that give me more power through out the rpm band instead of just the high rpms like the k27.

I was told that If I keep the stage 2 chips and add a 3bar fuel regulator with a k27, I would run rich on low rpms, but I would run ok at high rpms. And if I didn't use the 3bar regulator, I would run ok at low rpms, but lean at high.

I think its possible to run stage 2 chips with 3bar regulator, if you can find a turbo that generates more power throughout the rpm range instead of top end like the k27. I don't know if it exists, but if it does please let me know anyone? <img src="confused.gif" border="0">

Danno

Well, adjusting the FPR will shift your entire air-fuel ratio up and down across the board, but you can't change the shape of the curve. Here's what the resultant dyno chart will look like (thanks Dan Worley!):



This is the result of using chips mapped for a stock K26/6 turbo with a turbo that doesn't drop boost in the higher-RPMs. With higher-flow in the upper end, you'll have a lean situation there, even though the mid-range may still be correct.

And living with or putting up with a rich mid-range may not be the best thing for your or your car. You know about the fuel-washing-oil-off-the-cylinder-walls problem with too-rich a mixture. But the other thing too is that you'll be loosing a lot of mid-range power as well (and speed). A couple of years ago after I first put on my MAF kit and tuned it roughly with the ARM1 display, it looked OK to me. But a dyno-run showed I was overly rich at about 10.0:1. Dialing that back to a more optimal 12.0:1 gained me 70hp!

See here for a cheaper and better alternative to the MAF/ARC2 combo:

<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=18&t=001466" target="_blank">MAP sensor upgrade 1</a>

Doc

OK.. Call me stupid, slow, or just plain thick, however I don't see the value unless you're willing to through caution to the wind.

All I can see is one MASSIVE headache! It sounds like I'd have to be an engineer with a dyno at your disposal to be able to use ANY adjustable system properly.

DANNO's comment, " ...a dyno-run showed I was overly rich at about 10.0:1. Dialing that back to a more optimal 12.0:1 gained me 70hp!" only proves my point.

Sure he got a 70hp gain, but what if things had gone the OTHER way?! One wrong adjustment and I end up with a hole in my piston, or a rod through the block, etc. NO THANK YOU! <img src="graemlins/nono.gif" border="0" alt="[nono]" />

I've always felt the more you have to mess with the more likely you are to COMPLETELY screw EVERYTHING up. That's not a risk I want to take.

I'm not Steve Rustikov or Chris Cervelli (spelling?) and I don't want to worry about whether or not I got EVERYTHING right.

I'll take reliability over performance gains any day!

I’ll be real honest, I’m not too thrilled at the prospect of having to spend an additional $500+ for add-ons just to get an aftermarket turbo to work either. All of a sudden a $900 upgrade becomes $1500 to $2500.

I'd rather focus on decreasing my lap-times by improving my driving skills. Personally I’m just not at that stage yet where I'm wringing every last bit out of the car and I don’t want to mask any bad driving habits with horsepower. (ANYONE can put their foot down in a straight line!)

Somebody PLEASE prove me wrong! There’s got to be a way to get 350 (RELIABLE) rwph without spending a fortune. <img src="graemlins/soapbox.gif" border="0" alt="[soapbox]" />

(Sorry for the long rant.)

Russ Murphy

Correct me if I'm wrong, but the most reliable configuration for our cars is the way they left the factory. You want 84% more rwhp than stock, but you don't think you should have to make comprehensive modifications to get there. You know, like software that matches the altered parameters of your car's engine/turbo. If you want to wring almost twice the stock hp out of the car your're going to have to dial it in (or take it to somebody who'll dial it in).

Danno

"however I don't see the value unless you're willing to through caution to the wind."

I think it's really throwing caution to the wind to use a set of chips that are marginally programmed for a K26/6 turbo to begin with, and pairing that up with a completely different turbo with a completely different flow-pattern. As you can see in the chart above, the air-fuel mixture is far, far from ideal.

Sorry, I didn't make the later parts of my assertion clear enough. The first was that using Autothority Stg.2 chips programmed for a K26/6 will not be even close enough for a K27 turbo no matter what you do (much less a Garret). The second point is that obtaining some way of adjusting your air-fuel ratio is crucial to tuning. This means dyno time at a minimum, and custom chip-burning.

" but what if things had gone the OTHER way?! One wrong adjustment and I end up with a hole in my piston, or a rod through the block, etc."

My third point was that an immediately adjustable computer may be a better alternative to custom chip-burning, but it DOESN'T obviate the need for dyno-tuning.

"Somebody PLEASE prove me wrong! There’s got to be a way to get 350 (RELIABLE) rwph "

Here's what dyno-tuning will do for you:



A perfectly flat air-fuel ratio curve at the most optimum mix. This provides the MOST reliability by far as well as the most power.

That's my position, you HAVE to dial in an optimized air-fuel curve for YOUR particular configuration. How you accomplish this is up to you, be it custom-chips (not off the shelf) or an adjustable computer unit.

Doc

Russ, thanks for the input. I realize there are alterations to be made when increasing performance, however there are varying degrees.

The factory setup was based on many factors that don't apply to racing such as cheap gas, drivability in bumper-to-bumper traffic, emissions, mileage, etc.

What I'm looking for is a compromise that will get a moderate increase (we're not talking 600+ HP) without having to get a degree in engineering or spend a lot of dyno time tuning it.

Most guys like Huntley and Powerhaus push the ARM systems because it means lots of $$$ to them in additional parts and labor (as well as the ARM itself), not to mention continual upkeep.

Most club racers will tell you the *track cars* those guys build suffer from reliability issues and it's often due to the engine management systems. (Old racing truism- to finish first, you must first finish. ...and I'd rather finish last than not at all!)

I KNOW there HAS to be means available without going to an adjustable engine management system and I'm really only interested in people who can help with that. If it can’t be done, I'll stick with stock.

Danno

"I KNOW there HAS to be means available without going to an adjustable engine management system and I'm really only interested in people who can help with that. "

Ok, here's the miminum that you can do:

1. Go to the Mustang Ranch in Santa Clara after you install ALL your upgrades and do a dyno run (it will look like the first chart above).

2. Send the chart to Autothority and tell them your configuration and the version of chips you have. Tell them you want a set of custom chips burned to give you the air-fuel ratio found in the second chart above.

That's it! You'll have a perfectly optimized set of chips for your car. Perfect air-fuel ratio under full-load for the most reliabilty and power.

An alternative to #2 above would be to have some of the other folks who can custom-burn chips do it for you, like aka951 or TT.

Doc

DANNO... Once again, thanks for the input! Frankly that sounds a bit more reasonalbe. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Doc

Another quick question. Does anyone know of a turbo + chipset combo anyone sells?