[remops]

I started this project over a year ago and all along I was thinking I could use my stock crossmember. Now that I near the install I start to have doubts. Will it work with a single exhaust?

 

[oldeerslayer]

The only difference in the 30mm LS style trans mounts location and the earlier 298mm transmission isn't the actual location of the mount. It's in the same place, but the bellhousing on the LS version of the 4l60E is .400" longer. So when measuring from the front of the trans it will measure 13/32" closer to the front on the pre LS transmission. The distance to the rear remains the same. An LS engine with an LS transmission should line up exactly as it did before the swap. If you run an LS engine with the 4.3 transmission you'll need a spacer to correct for that .400". Which you probably already have to bolt them together correctly. Along with a pilot hub adapter and different flexplate and torque converter. It's because the LS block is shorter and the matching trans uses different input shafts.

4L60E (1996 and Later)
Bellhousing pattern - Chevrolet (removable)

Style​	A​	B​	C​	D​	E​
All (except Corvette and LS1)​	30 3/4 in.​	21 3/4 in.​	23 3/16 in.​	3 3/4 in.​	18 1/4 in.​
Corvette transaxle​	​	​	​	N/A​	N/A​
LS1 Style (1998 and Later)​	31 5/32 in.​	21 3/4 in.​	23 19/32 in.​	3 3/4 in.​	18 1/4 in.​

 

[remops]

Good Info that's what my understanding was before I had doubts. All these guys using aftermarket crossmembers got me thinking that I needed to buy something else but most were 2.2 trucks and dual exhaust setups. Being a 2dr blazer it is not practical and in some ways not safe to run dual exhaust. IE drivers side to close to gas tank. Now I just need to settle on a good quite single exhaust setup. Open for suggestions.

Thanks

 

[bk2life]

dual exhaust setups.

people always think they need dual exhaust for performance.
if youre under 500hp a simple 2.5 single exhaust will be more than adequate.
over 500hp step up to 3 inch.
600 hp use 4 inch
800 use 5 inch
1500 and more, start getting into 4 or 5 inch inch duals

 

[Tranzman]

Good Info that's what my understanding was before I had doubts. All these guys using aftermarket crossmembers got me thinking that I needed to buy something else but most were 2.2 trucks and dual exhaust setups. Being a 2dr blazer it is not practical and in some ways not safe to run dual exhaust. IE drivers side to close to gas tank. Now I just need to settle on a good quite single exhaust setup. Open for suggestions.

Thanks

I'm running a single exhaust on my LS10 swap.
Exhaust

• Custom built By Jeff @ Robs Auto (Cost was $900)
• 2-1/2” inlet 3”outlet Y-Pipe
• 3” Super Cat
• 3” inlet/dual 2-1/2” outlet Turbo muffler (I wish I had gone to a stock-ish muffler)
• 2-1/2” tailpipes with turn downs @ rear of bed.
• 2-Denso 234-4650 Upstream sensors (2004 Trailblazer 5.3L)
• 1-Denso 234-4647 Downstream sensor (2004 Trailblazer 5.3L)

 

[remops]

Stock-ish muffler ? To loud I take it? I read a thread where Philnix used a magnaflow and the finish off with a Spin Tech. I was toeing with the idea of something like that. Basically a resonator at the end of the system. Said it was quite. Also thought about the stock fullsize truck muffler.

 

[Tranzman]

Stock-ish muffler ? To loud I take it? I read a thread where Philnix used a magnaflow and the finish off with a Spin Tech. I was toeing with the idea of something like that. Basically a resonator at the end of the system. Said it was quite. Also thought about the stock fullsize truck muffler.

Yes it is louder than I expected, right now it will be ok . After driving a while I may change my mind and have a couple of resonators put on. the thing that's bugging me more is the noise from the valve train coming through the dash...

 

[jslezak83]

Blazers are tough. All that interior volume likes to resonate. I’d say find the biggest muffler you can fit to quiet it down some. Corsa is supposed to be real nice, but they don’t sell just the mufflers anymore.

 

[jslezak83]

the thing that's bugging me more is the noise from the valve train coming through the dash...

I just reread this, and it made me think. A friend of mine bought a 5.3L swapped Blazer with what looks like CPW motor mounts. The NVH was really surprising, and has me rethinking my motor mounts. Is this part of your issue?

 

[Tranzman]

I just reread this, and it made me think. A friend of mine bought a 5.3L swapped Blazer with what looks like CPW motor mounts. The NVH was really surprising, and has me rethinking my motor mounts. Is this part of your issue?

I'm using Holley mounts pads and 2002 Camaro Motor Mounts. Steering wheel is smooth as glass so it's not a vibration thing. What is the acronym NVH?? I'm not familiar with that.
I have only driven it to and from the exhaust shop. It just seems very noisy from behind the dash board. It seems like valve train noise.
I have some Idle tuning to do before I can drive it more. Once it reaches about 150 or so it starts dying out as you pull up to stops. I have it commanded to idle at 750rpm. I think the Idle airflow or VE tables are wrong for the cam. I'm running DBW and all the tuning info & video's are geared toward DBC systems.

 

[oldeerslayer]

I'm far from an expert on these things, but I don't understand how DBW would effect the tune. The timing and fuel tables would be the same, wouldn't they?
My LS4 GXP and 2500 HD LQ4 have no noticeable valve train noise. Haven't had my LQ9 S10 running long enough to tell, yet.

 

[Tranzman]

I'm far from an expert on these things, but I don't understand how DBW would effect the tune. The timing and fuel tables would be the same, wouldn't they?
My LS4 GXP and 2500 HD LQ4 have no noticeable valve train noise. Haven't had my LQ9 S10 running long enough to tell, yet.

I'm no expert either. It doesn't effect the tune per say, just some of the parameters on the how you go about it. For example DBC has an IAC motor, DBW does not. So how you go about the tuning parameters is slightly different. Some of the data logging uses different channels too.
it's like everything else when you get started. You read a lot, watch a lot of video's find conflicting information and don't know what to do or where to start. So you read/watch even more to find out what is crap and finally come to a place where you believe you can start. Some of the crap is because you don't understand or comprehend what you just read or saw yet...

 

[Life is a Enigma]

A friend of mine, a GM mechanic explained the differences between drive-by cable and drive by wire. He said think of it like a stick shift. drive by cable when you put it to the floor It takes about a second for the ECM to catch up and optimize the air/fuel ratio by RPM so its like shifting from second to fourth gear for about a second you get some lag before it catches up. The drive by wire its like a steady shift through the gears. The plate only opens as fast as the RPMs climb to optimize the air/fuel ratio with RPM. It still opens fast but not as fast as most people would like it to be. But you can go into the settings in HP tuners and change how fast the throttle plate opens for a faster response.

 

[jslezak83]

NVH = Noise Vibration Harshness. On my buddies Blazer, the steering wheel and dash have a buzz to it. I don’t know if it has poly body mounts too, but I know for a fact that I couldn’t deal with that. I may have to reassess the use of poly motor mounts.

 

[Harley]

I'm using Holley mounts pads and 2002 Camaro Motor Mounts. Steering wheel is smooth as glass so it's not a vibration thing. What is the acronym NVH?? I'm not familiar with that.
I have only driven it to and from the exhaust shop. It just seems very noisy from behind the dash board. It seems like valve train noise.
I have some Idle tuning to do before I can drive it more. Once it reaches about 150 or so it starts dying out as you pull up to stops. I have it commanded to idle at 750rpm. I think the Idle airflow or VE tables are wrong for the cam. I'm running DBW and all the tuning info & video's are geared toward DBC systems.

I had the same issue on my Blazer when I first got it on the road. I was originally using a base tune from an automatic - my truck is a manual - so there were some tables that were expecting a torque converter causing me some grief. Once I switched to a manual base tune it made a huge difference.

I'm a big proponent of getting the correct base segments loaded into the PCM before performing any tuning. I'm not sure if you've looked into segment swapping, but it essentially allows you to grab the exact engine, trans, vehicle, etc from the factory tune files and merge them into one. On my Blazer I started with a 2003 Blazer, merged it with a L59 5.3 from a truck and a Z06 T56 segment. Fixed a bunch of issues including the idle dying at stops. There are lots of tables to deal and even some hidden the segments include everything.

 

[Tranzman]

I had the same issue on my Blazer when I first got it on the road. I was originally using a base tune from an automatic - my truck is a manual - so there were some tables that were expecting a torque converter causing me some grief. Once I switched to a manual base tune it made a huge difference.

I'm a big proponent of getting the correct base segments loaded into the PCM before performing any tuning. I'm not sure if you've looked into segment swapping, but it essentially allows you to grab the exact engine, trans, vehicle, etc from the factory tune files and merge them into one. On my Blazer I started with a 2003 Blazer, merged it with a L59 5.3 from a truck and a Z06 T56 segment. Fixed a bunch of issues including the idle dying at stops. There are lots of tables to deal and even some hidden the segments include everything.

I'm running a LM4 block & crank with gen 4 flat top pistons. 243 heads on top, esentially making it an L33 engine assembly. The tune file is from a 2005 Silverado L33. i tried to match things to the best if my knowlwdge at the time. Tuning was not in my knowlege base at that time. I'm still a novice & learning...

 

[oldeerslayer]

Yup, no one mentions that you need to buy HPT to do a swap and I suppose you can get by w/o it, but seems like a lot of folks end up going that route eventually. I di and have ended up using it on my 377 L31 ZR2 before I even finished the LQ9 truck. Had some cold start and speedo issues. Actually haven't spent the $100 to license if for the LQ9 yet.

 

[bk2life]

I have some Idle tuning to do before I can drive it more.
Once it reaches about 150 or so it starts dying out as you pull up to stops.
I have it commanded to idle at 750rpm.
I think the Idle airflow or VE tables are wrong for the cam.

start with the idle tuning (Base Running Airflow) in park and drive from dead cold to 210 degrees. It takes 2 days to do that correctly. Alice took 14 minutes to go from 42 degrees to 210. Clifford (a basically stock truck) took 18 mins.
after you get that info, youll need to do VE tuning. without a wide band it takes about 30 mins or so to do everything under 4k rpms.
after that you have to do MAF tuning, also about 30 mins.
all of this is done under 4k rpms because it cant hit PE mode at all..this of course is without a wideband telling your AFR.
Once maf is done, then you need to recheck BRA and VE.
That should get your commanded idle to work as its supposed to. BUT, the surging and or dying at 'stops' is throttle cracker. you will need to add some air. There is no formula, this is trial and error.
This will get you up and running well. But anything that commands PE will be a guess, as o2s turn off and the computer relies on what's stored to give you fuel at full power.
So, without a wideband in the exhaust to show AFRs, you could be lean, rich, no one knows, because you're running off whatever GM has programmed for the vehicle the PCM came from.
You can dial in your cruise, stop light to stop light action, and everything under 4k rpms to be perfect. Then get it to a dyno and have your WOT and everything else tuned. Or by a wideband, and dial it in your self.

 

[Tranzman]

start with the idle tuning (Base Running Airflow) in park and drive from dead cold to 210 degrees. It takes 2 days to do that correctly. Alice took 14 minutes to go from 42 degrees to 210. Clifford (a basically stock truck) took 18 mins.
after you get that info, youll need to do VE tuning. without a wide band it takes about 30 mins or so to do everything under 4k rpms.
after that you have to do MAF tuning, also about 30 mins.
all of this is done under 4k rpms because it cant hit PE mode at all..this of course is without a wideband telling your AFR.
Once maf is done, then you need to recheck BRA and VE.
That should get your commanded idle to work as its supposed to. BUT, the surging and or dying at 'stops' is throttle cracker. you will need to add some air. There is no formula, this is trial and error.
This will get you up and running well. But anything that commands PE will be a guess, as o2s turn off and the computer relies on what's stored to give you fuel at full power.
So, without a wideband in the exhaust to show AFRs, you could be lean, rich, no one knows, because you're running off whatever GM has programmed for the vehicle the PCM came from.
You can dial in your cruise, stop light to stop light action, and everything under 4k rpms to be perfect. Then get it to a dyno and have your WOT and everything else tuned. Or by a wideband, and dial it in your self.

Yep I was told log 2 cold starts to warm up and use that data to configure the P/N idle, the do 2 in drive and use that data. do 2 warm to running temp under 2000rpm. Then you can go for the VE tuning.
I found a good idle tune how to from the HPtuners web site. its old and geared toward DBC.

Idle Tuning How-To & Guide (w/pictures)

IDLE TUNING Foreword by Rinkrat456: This article is literally copied and pasted from Krambo's Silverado SS page. He is an HPTuners member on this site. I take ABSOLUTELY ZERO CREDIT for the length of material you're about to read, however I have made a few comments in-text that you can see...

forum.hptuners.com

 

[oldeerslayer]

The steps listed above need to be a sticky in both V8 sections. Actually all engine sections since the info applies to all tunable vehicles. (98+)
Or better yet start a tuning section.