Last Sunday my recent purchase (04 RCSB) had a its first major mod performed on it.

I had Whiteside Customs in McKinney, TX install a Maggie TVS 1900, Pacesetter ceramic coated LT headers with catless mid pipe. He also installed. installer tried to talk me into the more expensive KOOK's set up but the Pacesetters were more in my budget. I also had him install a Street Scene rollpan.

The truck was dyno'd yesterday on a Dynojet 248 and the numbers have me scratching my head a little.
Baseline numbers were:
170RWHP
157RWTQ
Those just seem pathetically low. Like 6 cylinder low. Don't most of these 4.8's put out around 220 or so RWHP?
Post blower numbers:
313RWHP
358RWTQ

My installer explained that this particular Dynojet consistently reads about 10-15HP lower than others and that my wheel/tire combo is responsible for another 20-30 HP loss.

Does this sound right?

At any rate I picked up 143RWHP and 201RWTQ. The Maggie TVS1900 more than doubled my TQ.
I don't have the graphs yet but when I do get them, I'll post them up.

I'm picking it up on Sunday morning and driving it home from McKinney back to MO. Sunday evening I'll post up some driving impressions and maybe take some video.

My goal is a solid 500RWHP.
Cam
Heads
Pulley swap
And perhaps a different Dyno ha ha.

Here's some pics:
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3rd or 4th gear pulls? 4ths is your 1 to 1 and will rear more power but becareful as my factory driveshaft let go in the interstate around 110-120mph.

Also my 4.8/5speed with JBA shorties and diablo tuner made 243hp/262tq on a Mustang dyno. (Also reads low)

http://youtu.be/iw86tqYgB2M

 

Sounds about right.


If they are big wheels then yes, they will absorb a lot of power.

A different dyno won't make you more power. Remember it's just a number, it's what the truck actually does that matters.




Post some pics of this thing!

 

I never had my 4.8 dynod before it got replaced with a 5.7, but the 4.8 sure felt like 170hp.

 

Awesome build. I'm following on SSS.com too. Look forward to updates.

 

Thanks for the comments.

I picked up my truck last night from Whiteside Customs in McKinney. It worked out better to do that instead of pick it up this morning.

I'm very pleased with how the steel Street Scene rollpan turned out. I plan on getting the flip down license plate kit and installing a hidden hitch.http://
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Now onto driving impressions. Mike at Whiteside said the truck was a little bit louder but not as loud as he thought it might be with the addition of catless LT's. Upon startup the difference was quite noticeable. All good though. I dig it. But I have my eye on the Corsa side exit catback. Have always loved the LT/Corsa combo on the LS motors.

Messed around with both a 2 dr M3 and a Challenger R/T today. Wife was cool and let me play. Not quite enough to take the M3 but I got the impression he was supremely annoyed that he had to work as hard he did to beat pickup lol. FTR, I have 320lbs of sand bags in my bed for winter along with about 80 lbs of luggage, my old mid pipe/cats, stock headers and stock fuel injectors, IM. So I was hauling about 460 lbs of crap. The Challenger R/T wasn't as quick as the Beemer so he lost to pickup. He asked me "what the hell I was running" at the next light. I just said it was a 4.8 with LT's and a tune LOL. You cannot hear the SC at all. He strongly disagreed. It was fun.

This truck operates as though its stock. Very smooth. I could have left the shifter in 5th all the way home. It's diesel like in that no downshifting on any hill is ever required. It seems to pull as hard in 5th as it used to in 3rd. From 65-70 acceleration is effortless in 5th gear. Drop it into 3rd and it finds 100mph in short order. The tone of the exhaust note intensifies quite a bit when the boost comes on under WOT.
It seems to be a little drony at around 68-70 under load but it wasn't too bad. I've heard/experienced bad drone before and this was doable. Frankly I'm surprised that the cat-less LT's along with the turndown after the Flowmaster doesn't produce more drone.

I thoroughly enjoyed my drive home.

 

The wheels are heavy 20's with huge rubber on them. My speedo reads 5MPH slower at freeway speeds. When the tires wear down, I'll replace them with a lighter wheel with smaller rubber. Should pick up some gains there. Also need to put in a posi/LSD rear end.

I know it's just a number. Just some tongue in cheek. I am overall VERY happy with the gains I picked up.

The pull was made in 4th. The dyno shop's printer was out of ink I guess. Am looking into seeing if the data was stored somewhere and can be printed out.

The 4.8 does not feel like a sub 300 c.i. V8 anymore. It feels like a big block now. Gobs of torque.
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So you're the one with the crazy 4.8 on youtube? That thing is insane. How much boost are you running or is that top secret?

 

It's not to crazy, but with a older setup I was up to 21-22psi and 50 shot on top. Now with larger BW turbo I'm make better power with less boost.

Your truck sounds strong though. As long as your tunes right it will last a long long time at that power level.

 

Thanks. I had a few backfires coming home from from TX running on 91/93 with ethanol. Since being home and filling up with ethanol free 91, I have not had any backfire issues. The truck seems to behave very close to stock. My idle might be set a tad too low as it dips down to about 400 RPM momentarily when I let off and come to a stop. So far it hasn't died but I almost feel like its going to. Perhaps it's just something to get used to.

My installer said there was certainly more power to gain but he'd rather me drive something reliable vs. coming back in a month with a grenaded motor because we pushed it too hard.

The truck now redlines at 6300 and is governed to 130 for my own protection. He told me to upgrade the driveshaft and then we can raise that if I want. Personally I don't see the need. It's a fun 0-100 rig.