When to safely drop pulley size?

**2007GPGTSC** · 11-20-2013

Applicaion :

2007
Pontiac
GP GT S/C
100k mileage

Mods:
Intake
NGK TR55's
ZZP 10+mm wires
180* Tstat
ZZP 3" Cat'd DP
ZZP Plog - I made this choice budget wise because I am not building a track car simply a budget DD with some cojones

I know this post has probably been answered somewhere on the 100+ pages of forum info - although I would like some new input.

Just needs some facts no hating, just hard facts of what else I need to do to safely drop to a 3.6 pulley or lower while minimizing KR obviously - I know the gain will not be jaw dropping just want my DD to run purdy.

Keep in mind I have never scanned for KR and have no idea what it may be registering. Honestly I have no idea how to scan for KR with out an aftermarket gauge ect. quite frankly I have no desire to put an aftermarket cluster in. How shall I check for KR with out doing so ?

Thanks for your input !

**WolvesSoulZ** · 11-20-2013

Torque pro on your android phone to monitor on a budget/know where you are. It's a bit slower than a gauge, but it takes its data from the same source.

**2007GPGTSC** · 11-20-2013

Any idea which adapter would work on grand prixs?

**coolone** · 11-20-2013

OBD2 Bluetooth Adapter available on fleabay... $15-20... Torque Pro Android App $5... And you can read KR. 3.6 "shouldn't" be a problem... But measure knock before drop. You can't tune anything so if you drop and see KR, then you've got to pulley back up.

**2007GPGTSC** · 11-20-2013

Just out a curiosity what would the net gain be from dropping from a 3.8 pulley to a 3.6 pulley is the gain worth is? debatable? like I said I am not expecting jaw dropping 20+whp maybe a 3-6 whp gain would make me happy. How much would boost increase .5psi-1psi realistically ?

**ntreftz** · 11-20-2013

I use this one on my GTP
http://www.ebay.com/itm/Mini-ELM327-...item2eca27c2ee
I scan KR, Intake Air Temp, Boost<not true psi but close>, rpm, speed<no HUD> and Coolant temp. Refresh rate turned up, its fairly fast
make sure you upload all the PIDs from the setting menu

**darkhorizon** · 11-20-2013

10whp per .1 pulley drop is a good rule of thumb.

**Bio248** · 11-20-2013

Originally Posted by darkhorizon

10whp per .1 pulley drop is a good rule of thumb.

if everything is running accordingly, that is.

**blueguy** · 11-20-2013

negative results with knock.

Wheeeee, possibilities.

**2007GPGTSC** · 11-20-2013

Well I plan to do anything I can to minimize KR while still throwing some tasteful mods on her

**blueguy** · 11-20-2013

Just tune it and put in some poly mounts/shift kit.

Leave the stock pulley.

That'll really wake the car up.

Also, do the vent mod that most 04+ guys do...and toss an aeroforce gauge in there.

I'd have it read KR and something else.

**2007GPGTSC** · 11-20-2013

How hard is the install of an Aeroforce Scan gauge ? Never installed aftermarket gauges before ?

**sseilmnop** · 11-20-2013

Originally Posted by 2007GPGTSC

How hard is the install of an Aeroforce Scan gauge ? Never installed aftermarket gauges before ?

Plugs in to the OBD2 connector under dash. You just have to mount it.

**tomtom123** · 11-20-2013

How do you get the Torque App to read KR?

**blueguy** · 11-20-2013

Originally Posted by tomtom123

How do you get the Torque App to read KR?

You read.

**tomtom123** · 11-20-2013

Clever. Anyways, how do I see the level of KR using the Torque app?

Edit: Nevermind, I found it.

**GrandPrix06GT** · 11-20-2013

Aeroforce vent guage how to..
http://www.gpona.com/forums/04-08-gr...ls-t24978.html

and you should have all the chrome interior already seeing your an 07 GT like my 06 GT had it prior.

**blueguy** · 11-20-2013

Originally Posted by tomtom123

Clever. Anyways, how do I see the level of KR using the Torque app?

I wasn't kidding, start your own thread, quit cluttering up this one.

It's been covered numerous times if you just looked.

Mr. Clever.

**tomtom123** · 11-20-2013

Never said you were kidding. Just wanted a quick response which I feel would have been easy enough without smart replies. Not too hard to just point someone in the right direction. And to the original poster, sorry for cluttering up your thread with my pointless question. My apologies.

Mr. Clutter.

**savage93** · 11-21-2013

Originally Posted by 2007GPGTSC

Applicaion :

2007
Pontiac
GP GT S/C
100k mileage

Mods:
Intake
NGK TR55's
ZZP 10+mm wires
180* Tstat
ZZP 3" Cat'd DP
ZZP Plog - I made this choice budget wise because I am not building a track car simply a budget DD with some cojones

I know this post has probably been answered somewhere on the 100+ pages of forum info - although I would like some new input.

Just needs some facts no hating, just hard facts of what else I need to do to safely drop to a 3.6 pulley or lower while minimizing KR obviously - I know the gain will not be jaw dropping just want my DD to run purdy.

Keep in mind I have never scanned for KR and have no idea what it may be registering. Honestly I have no idea how to scan for KR with out an aftermarket gauge ect. quite frankly I have no desire to put an aftermarket cluster in. How shall I check for KR with out doing so ?

Thanks for your input !

I have similar mods plus a tune from Overkill and I run a 3.5" on my 2007 GT with no knock. I however do have 94 octane and an in car tune.