I am looking for some information on NorthStar engine swaps and tuning.
The engine is from a 2005 Bonneville GXP. Which I understand is not tuning-friendly. I've seen some references to N* engines run off of LSx PCMs, but nothing like a build thread.
The goal is to have the engine run independent of the auto trans as if it were hooked up to a manual trans, and have the ability to tune. There would be the possibility of boost if everything else can be worked out.
The other issue with lack of tuning means I have to find a way around the security system, which means determining what all the PCM has to be able to communicate with and getting those modules and anything they need to power on and communicate so the PCM doesn't go into a limp mode / no-run mode. I would much rather avoid such a mess of wiring and modules if possible.
I should mention I'm not doing a Fiero build and have worked out most of the other details for my swap other than the PCM/security/tuning.
The only person I know who does LS4 swaps near me is FieroKing. I don't quite understand your relation of the question to northstars, since the engine is from a GXP, but that is not my area of expertise. I'd PM Fieroking, or go to his website, and shoot him an email. He is the nicest, very helpful, and knowledgeable. I'd imagine that tuning these 5.3 LS4s wouldn't be much different than any other 3800 swap using the factory pcm.
Question - Respectfully, why would you not want the PCM to control both the transmission an engine? Having one programmable controller control both makes more sense to me, but who knows depending on your swap.
I don't quite understand your relation of the question to northstars, since the engine is from a GXP
-Mitch
EDIT: Welcome to the Forum.
Because the gxp's came with cadillac northstars. The best knowledge I've found is on this forum. Since I don't have that generation northstar I wont be much help on the electrical bypass'. Best of luck, more guys will chime in.
Theres MegaSquirt. Pretty sure it could run an 05 N*but it is completely DIY as far as tuning goes.
Chrfab sells a couple stand alone fuel systems designed for the northstar... More so than mega squirt. The problems that will arise are the vvt, security and such. He'd have to phone chrfab to see if their stand alones have been proven on 00+ engines. I know they were going to do it, not sure if they have yet or not.
I've personally ordered from chrfab, and have their old stand alone un as well as some other goodies. I wouldn't hesitate to call them again.
Because the gxp's came with cadillac northstars. The best knowledge I've found is on this forum. Since I don't have that generation northstar I wont be much help on the electrical bypass'. Best of luck, more guys will chime in.
Is that every gxp? I though bonnevilles had the N*, and the GXP had the 5.3L LS4 V8....
EDIT: Nevermind, I re-read the op. Bonneville GXP, if it was from a Grand Prix, that would be the ls4... by mistake
[This message has been edited by mitchjl22 (edited 02-03-2014).]
I am looking for some information on NorthStar engine swaps and tuning.
The engine is from a 2005 Bonneville GXP. Which I understand is not tuning-friendly. I've seen some references to N* engines run off of LSx PCMs, but nothing like a build thread.
The goal is to have the engine run independent of the auto trans as if it were hooked up to a manual trans, and have the ability to tune. There would be the possibility of boost if everything else can be worked out.
The other issue with lack of tuning means I have to find a way around the security system, which means determining what all the PCM has to be able to communicate with and getting those modules and anything they need to power on and communicate so the PCM doesn't go into a limp mode / no-run mode. I would much rather avoid such a mess of wiring and modules if possible.
I should mention I'm not doing a Fiero build and have worked out most of the other details for my swap other than the PCM/security/tuning.
I *think* the 2005 cars used the 58x trigger wheel, in which case the PCM can be tuned. You'll want to verify that your engine has the 58x wheel vice the earlier 24x wheel.
Do you want to run the automatic transmission separately controlled or do you want to run a manual?
The LS1 PCM with Shelby program only applies to '99 and older Northstar engines.
Don't worry about VVT. The front wheel drive Northstars never received VVT.
Swap is a '84 GMC K2500, trans is the 700-r4 with the FWD bellhousing and the 4WD output shaft. Mechanically it's bolt-in. No going for any speed records with this one, but the current motor only has ~230hp and is carbureted and just not a good DD anymore.
I'm running a Delphi MEFI 4b on my 2000 STS motor. I know my '00 has a different crank trigger wheel, and apparently different sensor placement, but the MEFI can use a 58x signal.
On another note, why can't the '00-'03 motors use an LS1 ECM/coils if they both have 24x crank and 1x cam sensors?
Swap is a '84 GMC K2500, trans is the 700-r4 with the FWD bellhousing and the 4WD output shaft. Mechanically it's bolt-in. No going for any speed records with this one, but the current motor only has ~230hp and is carbureted and just not a good DD anymore.
If you already have the engine, sell it, you are probably going to run into issues with the oil pan and have to fab mounts, the bigger issue, performance, I own an '04 SRX, yeah it's rated at 320 hp, at 6500 rpm . It makes almost no low end torque, a total DOG off the line. I can't imagine a worse V-8 to put in a 3/4 ton 4X4 truck, you will be VERY disapointed with the results of the swap your planning. My SRX doesn't "wake up" until about 3500 rpm
I'm not trying to be a "Debbie downer", just being realistic. Do yourself a favor and get an LS based engine, 5.3's are quite reasonable these days.
I'm running a Delphi MEFI 4b on my 2000 STS motor. I know my '00 has a different crank trigger wheel, and apparently different sensor placement, but the MEFI can use a 58x signal.
On another note, why can't the '00-'03 motors use an LS1 ECM/coils if they both have 24x crank and 1x cam sensors?
I forgot about the MEFI's. The LS1 and '00 Northstar wheels are different. Each is pulse width encoded so that the ECM knows which quadrant of the cycle it's in, but they're encoded DIFFERENTLY. I have no idea why GM did it that way.
quote
Originally posted by motoracer838:
If you already have the engine, sell it, you are probably going to run into issues with the oil pan and have to fab mounts, the bigger issue, performance, I own an '04 SRX, yeah it's rated at 320 hp, at 6500 rpm . It makes almost no low end torque, a total DOG off the line. I can't imagine a worse V-8 to put in a 3/4 ton 4X4 truck, you will be VERY disapointed with the results of the swap your planning. My SRX doesn't "wake up" until about 3500 rpm
I'm not trying to be a "Debbie downer", just being realistic. Do yourself a favor and get an LS based engine, 5.3's are quite reasonable these days.
Joe
What gears does the SRX have?
I find it interesting that you characterize it as not having much low end torque. I find my L37 has PLENTY for my Fiero, and will accelerate uphill in 5th from 1000 RPM. While a 4.6 liter engine just won't make as much torque as a 5.3 liter engine, and it definitely comes up on the cam around 3000 RPM, I would hardly say it's gutless.
The LH2 VVT engines are supposed to combine the low end torque of the LD8 engines with the top end power of the L37 engines.
Will I'll have to check on the gear ratio for my SRX. I'm sure your Northstar is great in your Fiero, I'm looking forward to getting mine running. Iet's be realistic, my SRX is probably about 5,000lbs, and your engine isn't exactly stock, I stand by my comments that it would be a disappointing swap in a 3/4ton 4X4. Why fight an uphill battle?
I will qualify my statements by adding that I've "heard" that Cadillac had reprogramed the ecm in the SRX to keep the transfer case alive, there does seem to be an issue with chains in these, I have not seen anything to substantiate the reprograming. Even so, I can think of much more suitible engines for his truck.
Will I'll have to check on the gear ratio for my SRX. I'm sure your Northstar is great in your Fiero, I'm looking forward to getting mine running. Iet's be realistic, my SRX is probably about 5,000lbs, and your engine isn't exactly stock, I stand by my comments that it would be a disappointing swap in a 3/4ton 4X4. Why fight an uphill battle?
I will qualify my statements by adding that I've "heard" that Cadillac had reprogramed the ecm in the SRX to keep the transfer case alive, there does seem to be an issue with chains in these, I have not seen anything to substantiate the reprograming. Even so, I can think of much more suitible engines for his truck.
Joe
There are some on demand AWD systems that can be "fragile" if they have to transmit a lot of power at a high duty cycle. The old Versatrak system in '90's minivans was like that. I don't know if that applies to the SRX or not. I don't know much specifically about Caddy's longi AWD hardware, other than that it is right hand drop when all of GM's AWD trucks and truck based SUV's use left hand drop. Its durability may be compromised for packaging.
Have you driven a RWD STS with the LH2?
BMW builds the X5 with 4.4 liter V8's and the LH2 makes at least as much low end torque as the M62B44.
There are some on demand AWD systems that can be "fragile" if they have to transmit a lot of power at a high duty cycle. The old Versatrak system in '90's minivans was like that. I don't know if that applies to the SRX or not. I don't know much specifically about Caddy's longi AWD hardware, other than that it is right hand drop when all of GM's AWD trucks and truck based SUV's use left hand drop. Its durability may be compromised for packaging.
Have you driven a RWD STS with the LH2?
BMW builds the X5 with 4.4 liter V8's and the LH2 makes at least as much low end torque as the M62B44.
When I bought my SRX I was looking for a rwd version, (if the Nstar gives me any trouble, I'll tear it and the awd out and create an SRX-V ) the one I wound up with awd and all, was a low mile car that was in my price range. LH2 is the engine in both rwd and awd SRX's, I wish I had driven one in rwd before buying this one. The trans is a 5L50e, Cadillac upgraded the SRX to a 6L80e in '07, Chain stretch is a known problem on the transfer case, soo... it's not hard to believe that the ecm "may" have been retuned to "soften" the bottom end. Once I get past about 3500 rpm the thing is downright fast, there is a defiant Dr Jekyll / Mr Hyde thing going on under the hood. it has suprised a couple of people.
Getting back to the op, (sorry for the hijack) I still think he'd be happier with a bigger engine with more low end. The Northstar may be Cadillac's signature engine, going so far as to use it in the short lived XRL, but rely on the LS series in their big suv's.
. It makes almost no low end torque, a total DOG off the line. I can't imagine a worse V-8 to put in a 3/4 ton 4X4 truck, you will be VERY disapointed with the results of the swap your planning. My SRX doesn't "wake up" until about 3500 rpm
) the one I wound up with awd and all, was a low mile car that was in my price range. LH2 is the engine in both rwd and awd SRX's, I wish I had driven one in rwd before buying this one. The trans is a 5L50e, Cadillac upgraded the SRX to a 6L80e in '07, Chain stretch is a known problem on the transfer case, soo... it's not hard to believe that the ecm "may" have been retuned to "soften" the bottom end. Once I get past about 3500 rpm the thing is downright fast, there is a defiant Dr Jekyll / Mr Hyde thing going on under the hood. it has suprised a couple of people.
