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Cryptic
01-24-2010, 11:53 PM
I've got a bare long block 427 LS3 with the 58 tooth reluctor wheel. I'm trying to decide what is the best (or maybe cost effective) path to take.

The RX7 already has a throttle pedal that has a cable that works for cable driven throttle bodies. I think I would like to stay with a cable setup (unless there's some compelling reasons not too). I understand that to switch from DBW to Cable, the wiring harness will need to be modified by adding TPS and IAC connectors and removing the DBW Throttle Body connector.

Is the rest easily handled by the tuner?
Is this just a flash change?

I'm looking for suggestions where to purchase the wiring harness & ecm. I didn't see on Painless (http://www.painlessperformance.com/webcatalog/largeview.php?SearchField=60524) a specific harness for a cable driven conversion. I'm pretty sure this has been done before.

Or should I forget the whole idea and just go with DBW and get a new throttle pedal and slightly more costly TB.

*awaits BADLS1 reply*

BAD LS1
01-25-2010, 06:19 AM
Well there there is some uncertainty about using a PCM that is meant for ETC already and converting back to cable control... I know it can be converted from cable to ETC easily using an LS1 PCM. Im not sure that a Painless pcm would use an LS2 style pcm that i could actually access, but then again that's ETC only too.

Easiest way i could see it is a LS1 style PCM and harness, with an LS2 conversion to extend the map, cam and knock sensor harness. Hopefully the shortblock has a 1x cam sensor reluctor? (1 C shaped ring on the big cam gear, 4x: 4 bumps on the cam gear)If its 4x then you will have to change the cam gear. One could use a lingenfelter 58x to 24x converter box then use a cable throttle body. If you use a complete L76 or LS3 intake you will need EV1 to EV6 adapters for the injectors too if an LS1 harness is used.

Really the only benefit is being able to ditch the cable in favor of aesthetics.

SLOWC5
01-25-2010, 10:43 AM
www.currentperformance.com

Cryptic
01-25-2010, 01:33 PM
I haven't looked but I think it's reasonable to assume that I have the 4x cam sensor for the 58x reluctor wheel. According to the build sheet, that's what's in there.

I was hoping to run the FAST 102mm Big Mouth Throttle body and intake, but that's sold only as cable driven. No DBW version available.

So to clarify, to get cable throttle body to work, I would need:

GM 1997 - 2004 LS1 LS6 Fuel Injection Harness Mechanical Throttle Body - P/N 60508 (or equiv) (http://www.painlessperformance.com/webcatalog/largeview.php?SearchField=60508)

lingenfelter 58x to 24x converter box part No. 1L460065397, $254

Injector Connector Conversion Adapter Harness LS1 to LS2-EV6 USCAR (http://www.lingenfelter.com/mm5/merchant.mvc?Screen=PROD&Store_Code=LPE&Product_Code=CE-109076&Category_Code=C162) Part Number: CE-109076 Price: $62.95

GM LS1 Knock Sensor & Cam Sensor Adapter Harness - Allows Easy Upgrade to LS2/LS3/LS7 Engine (http://www.lingenfelter.com/mm5/merchant.mvc?Screen=PROD&Store_Code=LPE&Product_Code=CE-109081&Category_Code=C162) Part Number: CE-109081 Price: $54.95

27" MAP sensor extension harnes (http://store.katechengines.com/shared/StoreFront/product_detail.asp?RowID=19&CS=katech&All=)s SKU: KAT-4751 List: $33.95

and possibly ???:
LS2/LS7 90mm throttle body on LS1/LS6 - Throttle Body Adapter Harness (http://store.katechengines.com/shared/StoreFront/default.asp?CS=katech&StoreType=BtoC&Count1=492168605&Count2=409309029) SKU:KAT-4752 List: $50.00

So do I loose any functionality running a LS1 PCM over a LS3 (E38)??

I can't believe their isn't a easier solution to convert LS3 to Cable driven and retain a 58X reluctor. Why go backwards?

Cryptic
01-25-2010, 02:19 PM
Taken from KaTech - 90mm Cable Throttle Body LS2/LS3/LS7/L92/L76 (http://store.katechengines.com/shared/StoreFront/default.asp?CS=katech&StoreType=BtoC&Count1=355892360&Count2=273032784&ProductID=36&Target=products.asp)




Install a FAST 90mm, LS2 or LS7 intake in any car
Does not include IAC, TPS or cable retainer bracket


That says to me that all I should need IAC, TPS sensor on the throttle body, and a cable retainer bracket.

F.A.S.T. has that (Fast Big Mouth 102mm TB w/TPS) (http://www.compperformancegroupstores.com/store/merchant.mvc?Store_Code=FS&Screen=PROD&Product_Code=54103)

I guess I don't understand how the IAC and TPS is then wired to a LS3 harness. This is the big mystery. Did I just prove to myself that this isn't possible?

BAD LS1
01-25-2010, 02:55 PM
Taken from KaTech - 90mm Cable Throttle Body LS2/LS3/LS7/L92/L76 (http://store.katechengines.com/shared/StoreFront/default.asp?CS=katech&StoreType=BtoC&Count1=355892360&Count2=273032784&ProductID=36&Target=products.asp)



That says to me that all I should need IAC, TPS sensor on the throttle body, and a cable retainer bracket.

F.A.S.T. has that (Fast Big Mouth 102mm TB w/TPS) (http://www.compperformancegroupstores.com/store/merchant.mvc?Store_Code=FS&Screen=PROD&Product_Code=54103)

I guess I don't understand how the IAC and TPS is then wired to a LS3 harness. This is the big mystery. Did I just prove to myself that this isn't possible?

I cant see it working either, the IAC is the TAC motor in the ETC and there would be a reostat for a TPS like a conventional one could tap into at least.

Your above list covers everything i can think of, but the LS1 f-body style harness will have TPS and IAC provisions already in place, the LS6 vette will not. The only thing i can see extra is the 1X cam gear kit from lingenfeltcher.

The E38 pcm has a processor thats twice as fast and can do more, but the plain ole f-body LS1 PCM is plenty fast and has tons of adjustabilty so i dont see a better way to do it while still maintaining a cable throttle.

If you want to save the extra cost of the 58x-24x converter, one could buy a 24x wheel for $15 and pull the crank and swap out the wheels provided they didnt WELD the reluctor on. I have a jig for reinstalling those.

Prince Valiant
01-25-2010, 04:56 PM
Man, SO much more complicated "what size carb should I buy" questions of old, lol...