GFallen

With the Maggie installed for about 1k I now am getting "reduced engine power" in the display. I was told and did a little research that I'm probably gonna need a new throttle body. I saw a guy on ebay selling ls7 which he states have stronger "motors" and hold-up to the extra air flow when supercharged. My question is does anyone know if my stock throttle body can be "saved" with a port and polish or should I buy a new ls2 or go with the ls7? and if I bought the ls7 would I need a new tune? thanks

DMM

The LS7 and LS3 open in reverse from the LS2 and will cause issues that cannot be corrected unless all of the DBW tables are changed...which can brick the PCM.

Check the connector and harness carefully as this code is usually set by a bad connection etc that causes one of the three tables to read low on voltage. Could be the TB or pedal assembly, but is usually a connection issue somewhere. Same thing happens to my truck now and then. Since your harness was extended, i would give it a tug and see if anything changes.

FuzzyLog1c

iTrader: (4)

Based on your last couple of posts, I think you need to slow down before you mess up your car. You need to get a OBD2 scanner on the car to figure out what exactly is going on.

The LS7 TB opens the opposite direction that the LS2 TB does. It won't work, and there's no workaround. Not for lack of trying--anyone who could manage that would make a mint, since the LS2 TB is rare and expensive.

Edit: DMM beat me to the punch.

vmapper

iTrader: (8)

You need to determine which codes are thrown putting you in REP

You could simply be triggering P0068 which is the ECM determining the maximum airflow the ETC should be passing at a certain Throttle position and RPM.
You are Forced Induction... its possible.

Or its the throttle, or a few other things as the above two have mentioned. Wiring is another very possible issue... hence why you need to narrow it down, to confirm, by getting which codes were thrown.

Ill say it, others will dispute, but it just means they dont understand the entire ECM picture.
ANY THROTTLE SIZE CHANGE REQUIRES A RE-TUNE. Its the PROPER WAY, as its not just idle affected. its all TPS postions at all rpms.

etcts-v

I installed a LS2 on my LS6 a week ago, car's running but obviously not optimum as there is a rough idle when I first start up. In a few weeks I'm going to purchase a Fast 90 or 102 to compliment followed by a 2nd tune, what part of the maps should I make sure to have my tuner modify for the LS2 throttle body when I take it in for tune next month?

I did through a P0068 code the other day with the setup, but at least the car can drive where as with the LS6 ported intake I was dead in the water with instant reduced power mode!

2nd question, I've been considering purchasing EFI Live or HP tuners (been studying up on how to tune with a few books). Question is the car has already been dyno tuned, is it relatively easy to make changes for the LS2 throttle body and Fast intake on top of the tune he already did? I would rather spend the $500 on HP tuners than a 2nd dyno tune!!

DMM

To the last...the TB scaler needs to be corrected in your tune, easily done with HP or EFI. Google "LS2 TB scaler setting". With any tuning Software you will need a wideband, so you are looking at about $800 all told. I would start a new thread regarding this rather than muddy this thread. Sorry OP, back on topic.

etcts-v

Was trying to get CTSVMAPPERS opinion which is why I snagged the opportunity to ask.

Sorry for thread jacking...

vmapper

iTrader: (8)

Here is a simple worksheet download to determine the value for the 04-05 ECM.
so, 90mm LS2 throttle will have a physical size value in the ETC Scalar of 0.0192. This allows the ecm to use the correct 'stepping' of the motor and know how much air will flow.
You can see, once you hand port, your values will not be exact, and the variance will be burned in either tuning the injector tables and or MAF/VE tables along with Idle tables. (RAF).

Muddied thread a bit further.

scatillac

iTrader: (12)

There are actually 2 LS7 throttle bodies, the early one, which is valid through, I believe, the '07 model year. It can be identified by it's aluminum-colored throttle blade, moreover, it's the same PN as an LS2 throttle body and is also compatible with the LS6 ECM through an adapter harness or a plug change and minor rewiring, and of course, a re-tune.

The late LS3/7 throttle body can be easily identified by it's brass-colored throttle blade. It also has a different plug for the electronics.