Sounds good but it went upside down for a second there. 
What are you using for tuning software?
What are you using for tuning software?
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
sas on 2003 2500hd
- Thread starter rob h
- Start date
I went inside to show the gauges but it didn't work out. too well sorry..That's why i said its poor quality, there was alot of things going on in town so there was alot of noise. I had to get close when taking the video, i will get a new one once i have it tuned properly. This did show the 2 most important things tho, sound and the motor running. The lifters are a little loud, if that doesn't calm down i will need to adjust push rod length. If you took notice the air fuel gauge is blank' its lean at idle and pretty good everywhere else. I have blackbear performance for tuning, its with efi live and uses an auto-cal. I connect it to my 0bd2 port and take a log of it then hook it to my laptop and send it to him. Then they send up dates and changes, back and forth till its all good. I watch all the gauges and make sure everythings ok each time, also the autocal shows most of the parameters.
Oh okay, I didn't know if you were tuning it yourself or not. I've heard plenty of good things about Blackbear.
No tuning myself yet anyway, i'm leaving it to the experts. The auto-cal package came with the supercharger when i ordered it. Its way better than a canned tune, wouldn't run like it does with one of those. They do a really good job, sometimes they are really busy but always pull thru. I'm glad this job went well so far, i can't wait till i can really step on it and see how well the cam does. To me it really sounds good, still need idle and afr adjustments so the tone might change some. I'm now running the smallest blower pulley and the biggest crank pulley for this setup, it will do 13-14 psi but i won't keep it up that high.
Here's a better video
I ran into a few small problems. The ls3 90 mm throttle body can't handle the airflow and it gets blown shut, causing reduced engine power and a p1515 code. I had to swap it out with a 90 mm ls2 throttle body. The ls2 and ls3 look the same except the ls3 has a gold blade and the ls2 has a silver blade. The ls2 motors alot stronger too, since that swap the code or rep mode hasn't come back. I put new front o2 sensors in and one reads pretty bad, the truck ran when i started it like an old truck with a carb until warmed up. I put an old one back in and its runs fine...that sucked. I'm also still tuning with my data log fixing the fine details, the wideband under boost shows about perfect in the 11s and idle i see high 15s. That needs to be adjusted to at least low 15s to be right. Also had to adjust the fuel pressure to base of 58 like stock, under boost its in the 60s. Here are a few pics, both throttle bodies, new 90 mm installed, the stock regulator block off plate and the new regulator hidden behind the supercharger.
Last edited:
I didn't realize the LS2 throttle body was a 4 bolt pattern. Also didn't realize that you could overpower the throttle body motor. 
Now this is an ls2 car throttle body for an 05-08 z06 or 05-09 g8... gm part # 12570790. These open different and need the xlink adapter that i used in a previous post to open all the way and work perfect. What happened is now with the cam and with more air flow the pedal says open but on the other end its blown shut. Putting the pcm in reduced engine power, which sucks but now it's fixed. Part of the ls3 being blown shut is the way it opens and shouldn't be used in forced air applications.( wish I would of known) The stock trucks throttle body is totally different and 3 bolt, what helps Is my supercharger is 4 bolt too so no adapter is needed.
Last edited:
So only GenIII trucks were 3 bolt throttle bodies? I thought all GenIIIs were 3 bolt. Then all GenIVs were 4 bolt?
They use the same style supercharger inlet on the tvs1900-2300 for many years of cars and trucks, Being 4 bolt with a 3 bolt adapter plate just makes it easier for them. For the trucks that sounds right being 99-06 3 bolt and 07 up 4 bolt. Also drive by cable from 99-02 since the 03 up is by wire. The cars were about the same, certain years stayed by wire until 04. Also 3 to 4 bolt in some years longer than others, The silver blade throttle body like i said only certain cars had them, i'd imagine that's why they are 400, plus dollars. From the dealer my ls3 was 160.00 new in the box, the ls2 is 487. Thats crazy and i would not pay that, i found a new one in the box on ebay from a gm dealer for 375. If it didn't make such a huge differance i would of put the stock truck 78 mm back on. This mod i only did with the 90 mm since that's the size of my inlet, if it was bigger i would of bought a 100 mm. This mod was also proven to make a power/torque improvement to justify the cost. I'm also thinking of sending it out to get ported, i did see proof of 8-13 hp with just doing that.
What about aftermarket 90mm throttles? Would they be cheaper than the LS2?
I had the 90mm on my LS3 Camaro ported and maybe it made 5hp more. But it made a noticeable gain in throttle response, enough I'd say it's worth it. I ended up swapping on a stock one before I traded it in and put the ported one on my 6.2 L9H truck.
I'm betting with forced induction it'd make a bigger difference though.
I had the 90mm on my LS3 Camaro ported and maybe it made 5hp more. But it made a noticeable gain in throttle response, enough I'd say it's worth it. I ended up swapping on a stock one before I traded it in and put the ported one on my 6.2 L9H truck.
I'm betting with forced induction it'd make a bigger difference though.
I was told by a friend that is a mechanic at the local gm dealer for years to stay away from the aftermarket stuff, they are nothing but problems. I was going to buy one of those since they are way cheaper and look pretty close. I'm not really sure why the ls2 is alot more money but 250 plus more is alot more cash. It was worth it tho i guess since i have no problems now, I was wondering about porting and would it be worth it to have done. I might give it a try, every little helps..lol. Who did the porting on yours. .? I searched today . I found 2 places that cnc machine them and flow test them. Both places are around 150.00. To do that i will put the ls3 back on and ship mine out to skip the core charge fee and just pay shipping.
Remember being forced air like the magnuson, lsa or Whipple the ls3 is not ideal at all. It has something to do with the pd blowers. The external mounted blowers like procharged don't seem to have the problem. The throttle response and the torque differance is what makes the 90 compared to stock shine. The 90 on your 6.2 truck would only really benefit if the intake inlet supports it, i would imagine its fine since its a bigger motor. Exactly like you said tho the bigger throttle body works perfect with forced air. That 6.2 truck probably runs really good, there must be 10 new trucks at work and they are all 5.3s.
For example....I have a friend with a 2012 white camaro, 2 ss, 6.2. Its now bored to a 7.0 litre with twin turbos behind the rear bumper. Was just dynoed at 800hp, that car is fun but a hand full. he runs the ls3 throttle body and has no problems at all.
Remember being forced air like the magnuson, lsa or Whipple the ls3 is not ideal at all. It has something to do with the pd blowers. The external mounted blowers like procharged don't seem to have the problem. The throttle response and the torque differance is what makes the 90 compared to stock shine. The 90 on your 6.2 truck would only really benefit if the intake inlet supports it, i would imagine its fine since its a bigger motor. Exactly like you said tho the bigger throttle body works perfect with forced air. That 6.2 truck probably runs really good, there must be 10 new trucks at work and they are all 5.3s.
For example....I have a friend with a 2012 white camaro, 2 ss, 6.2. Its now bored to a 7.0 litre with twin turbos behind the rear bumper. Was just dynoed at 800hp, that car is fun but a hand full. he runs the ls3 throttle body and has no problems at all.
Last edited:
The guy who dyno tuned the Camaro did the porting. He did it by hand with a carbide bit on a Rotary tool and a round file. Probably had it done in 15 minutes lol.
The truck 6.2s got 87mm throttle bodies from the factory. The intake throat is actually bigger than that and a 90mm is a direct bolt on. Well except for the stepper motor sticks out on the LS3 and interferes with the factory intake tube with all the baffles and noise canceling chambers but come on who actually runs that restrictive pos.
The '09-'13 6.2L trucks are great. VVT without the AFM, best of both worlds. I'm planning on a mild VVT cam for it actually.
But stock for stock way faster than the 5.3L and didn't get that much worse for mileage. The factory tune is so lean and lazy though.
That's nice that the 90mm is a direct bolt on and the intakes set up for it. The newer truck have a higher hp stock too which helps a ton. Mines only 300 stock, I bet that 6.2 is probably 400 or more. If u don't mind me asking who did your tune and porting..? Does he have a Web site..?
A cammed 6.2 you would prob be like 450 hp tuned which would be awesome. It sucks tho is to do a cam in the ls it's not too cheap. I think with all the stuff I bought I prob have 2k into that part of my build. That's not being cheap about it and buying big name parts that have a good rep.
http://slowhawkperformance.com
This is the shop that did the tuning to all my LS vehicles including the porting on the throttle body. He mostly works in house on stuff, I'm not sure if he does mail order stuff. Don is the guy who runs the place but is hard to get on the phone, I'd recommend emailing.
The L9H in my truck is rated at 408hp stock (at the crank). I never dynoed mine but Similar trucks to mine with the same mods were making 365-375 rwhp. Dyno sheets on the cam I want put it at 450-460 rwhp. That'll be enough to keep me happy for a while. I'll have to save up some cash though.
I sent an email, Don got right back to me within an hour, he said 75.00 he ports them for. That's the cheapest so far, how good does it look done by hand..? If they look good and work good I'll send it to him, it's the closest too
The porting job was great. I don't see a reason to spend double for the same thing.
Here's a pic. Stock 87mm vs the ported 90mm:
That looks great. Thank you for all the info on this, every bit of hp/torque/throttle response i can get helps a ton. He's on vacation this week so that will give me a chance to get it off and boxed up to ship to him. Hopefully he has a decent turn around after he gets it. Seems like a good guy from the few emails he sent,
Stock 87mm,,,huh,,, mine i'm pretty sure had a 78 mm, huge differance of almost 1/2 an inch bigger than stock.
Stock 87mm,,,huh,,, mine i'm pretty sure had a 78 mm, huge differance of almost 1/2 an inch bigger than stock.
That's good to hear that he's hooking you up. Let me know how it goes.
Will do, ill get it off this weekend after the bloomsburg offroad jamboree. I'm also going to start plumbing my alky control kit.
