924Board.org

PORSCHEV · Posted: Mon May 07, 2007 8:04 am Post subject: Throttle body Question

Forgive me if sounds like a Noob question..........

Ok...Here is a picture of my throttle body linkage. Today while messing with the timing/idle, I found the engine really came to life when the secondary butterfly would open. There doesn't seem to be any way of adjusting this so I wanted to experiment how the engine would perform if the butterfly opened sooner. Thats the reason for the tie-wrap

The results were Freakin AMAZING!! It felt like I just added 50 hp!

The car actually smoked the tires (P245's on the Rear).

The big question is can this hurt the engine in anyway? I assume it is just getting more air and that can't be a bad thing....

What would be the best perminant mod I could do to keep this level of performance?
_________________
1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

Min · Posted: Mon May 07, 2007 8:15 am Post subject: Re: Throttle body Question

Eturbo924 · Joined: 09 Nov 2002 Posts: 2212 Location: Londonderry NH

Can't see how it could hurt.

The reason for the two different openings is so that part throttle driving is a bit smoother.

Eric
_________________
1982 924
1992 968
2003 C4S
Parts Parts Parts and More parts.
E-mail me for parts you need!
Drive Fast!

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

The Audi (5000?) throttle body has a bigger 2nd butterfly and it opens sooner. It's a direct bolt-on replacement for a NA TB. When I fitted one to my car I couldn't believe the difference. Definite improvement.
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

I've got the Audi 5000 throttle body on my car too, great junk-yard purchase.
_________________
1987 951 - M193 Version for Japan

StienbargerR · Joined: 28 Oct 2005 Posts: 1362 Location: Richmond, IN

I think this has been discussed before, but how does the audi 5000 mod do in normal traffic? Is it touchy or ok? I think the throttle response is a bit poopy in my car, so this might be worth the conversion.

Ryan
_________________
1978 924 NA
-250lb lowering springs, Euro Pistons

PORSCHEV · Posted: Tue May 08, 2007 6:32 am Post subject:

Thats the only draw back of how it is now..very touchy at around 2000 rpm. You need to use a bit more force on the pedal....but then the car will lurch ahead because the pedal will jump the throttle open...just isn't smooth. I have already been looking on ebay for the audi 5000 TB...but no luck yet. What aother TB are the same as this...VW passat I read somewhere when doing a search.
_________________
1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

StienbargerR · Joined: 28 Oct 2005 Posts: 1362 Location: Richmond, IN

good to hear.

Ryan
_________________
1978 924 NA
-250lb lowering springs, Euro Pistons

Benino · Posted: Wed May 09, 2007 4:08 am Post subject:

About the zip tie modification: I'm not really a fan of that kind of "upgrade". all it does is change how fast you get to full throttle. Now you are going from 0 to full throttle in the first 1/2 of pedal travel. Does it really take that long to push the pedal all the way down? If you want to go fast just floor it. lol. you get the same result, and then you aren't sacrificing smoothness and driveability.

The Audi Throttle body is actually larger so you do get a larger opening at full throttle. This actually is an upgrade, although the gains are not very significant because as mentioned above the real bottleneck is the head.
_________________
1980 Porsche 924 N/A USA
1980 Porsche 924 turbo USA
1987 Porsche 944S USA

Eturbo924 · Joined: 09 Nov 2002 Posts: 2212 Location: Londonderry NH

There is no actual gain in performance with a larger throttle body. This was proven in the bolt on articles. I have these at my site and they are linked here on 924.org some where.

In combination with many other modifications it did seem to add some thing to mine but all alone it does nothing. In my case it also seems to rob the engine a bit if I floor it at low rpms... the opening is to large. At high rpms is the only place I can actually have it fully open and take advantage of it.

I have a ported and polished head, muti angle valve job, slightly hotter cam, header with 2.5 inch free flow exhaust with 944 turbo muffler. Also have a ported intake to match the throttle body and a cold air intake. All of this definately makes it quicker than your standard 924 and just as quick as American 931s. But that is not saying much since they are only rated at 9.3 sec to sixty and my car was just about that quick stock... believe it or not.

I ran many trial runs (yes with a hand held stop watch) that were always better than 10 sec to sixty when I was younger. So maybe my car was a bit stronger to start.

I ran against a 931 a few years ago on the highway and was able to stay with him quite easily. Of course his car looked no where as nice as mine so I am sure he was not making full power... but then again I did not need to use all I had. When I did I began to overtake him.

And no... he was not dragging an anchor

That said... I kind of got off target here. The throttle body alone will do nothing.
_________________
1982 924
1992 968
2003 C4S
Parts Parts Parts and More parts.
E-mail me for parts you need!
Drive Fast!

PORSCHEV · Posted: Wed May 09, 2007 6:41 am Post subject:

I guess I'll have to live with my imaginary power.

_________________
1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

NEMESIS · Posted: Wed May 09, 2007 8:23 pm Post subject:

Has anyone used the Weber "Big Bore" TB?

I bought a kit from them years ago when we had an NA car but never used it. It's a single butterfly arrangement so the throttle response should be much more aggressive.

Eturbo924 · Joined: 09 Nov 2002 Posts: 2212 Location: Londonderry NH

It is been tested and shown to do nothing.

There was a note in the article about a percieved feeling that the throttle response was better. Thus the same feeling that the original post was about. If you open every thing up faster the perception is that the engine is making more power. When all that is actually happening is that less foot travel makes for more air and fuel into the car.

Or... maybe PORSCHEV your car is different from all the rest

.

Read the articles. They make is all clear.
_________________
1982 924
1992 968
2003 C4S
Parts Parts Parts and More parts.
E-mail me for parts you need!
Drive Fast!