Increase power

Traz

Original poster
Jan 10, 2018
134
Michigan
Hey guys just wondering if there's any bolt on power for the 4200. I'm already working on a turbo kit but wondering if there is anything else out there. From what I've gathered online the aftermarket support for it is minimal but some people have found some things. Anything helps. Thanks
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Get the PCM tuned.

You wont gain anything from intake or exhaust n such on these.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Headers might help a bit. Check on eBay. Not speaking from experience though. If my manifold ever cracks, I might go this route.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
WHY? The header only adds power w a tune and no proof it’s anything over a tune alone....
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Quite possible since the stock manifold doesn't look restrictive. Just going by experience with V8's.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Since they came out years ago we been waiting for some dyno to justify a header...either no tune to header/no tune or tuned before and after header. Seems to only be stock vs header with tune is available.
 
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I_Shoot_Back

Member
Feb 18, 2018
116
Ponoka
Stock headers might not be restrictive but a well designed header creates a negative pressure in the collector for the next pipe's exhaust.
I'm also very curious to hear about a let's say: cat delete,header,open intake and a tune and see how much it opens the engine up.
*edited from might not look restrictive to might not be restrictive*
 
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Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
The stock exhaust system is said to not be very restrictive.
 

Reprise

Lifetime VIP Donor
Supporting Donor
Member
Jul 22, 2015
2,724
The stock exhaust system is said to not be very restrictive.

I'd tend to agree with that (at least until it hits my muffler - that thing is so huge, I can't believe it wouldn't be restrictive in some fashion.)
When I go, I'm going to specify in my will that it serve as my casket...LOL

I was going to say there wasn't much in the way of catback support - but doing a quick search just now, it's more than 'nothing'. Even the I6 has some support (no clue on how well it works / bang for buck, since it looks to have a glasspack for a muffler)
 

littleblazer

Member
Jul 6, 2014
9,265
The only exhaust gains to really be had are going to the later model exhaust manifold from the early style. I believe the switch was 06 though so you're covered. Worth a couple IIRC... Turbo or stroker is the way to go granted I have never seen a stroker 4200 that I know of.
I'd tend to agree with that (at least until it hits my muffler - that thing is so huge, I can't believe it wouldn't be restrictive in some fashion.)
When I go, I'm going to specify in my will that it serve as my casket...LOL

I was going to say there wasn't much in the way of catback support - but doing a quick search just now, it's more than 'nothing'. Even the I6 has some support (no clue on how well it works / bang for buck, since it looks to have a glasspack for a muffler)
The big muffler isn't restrictive, Since the air space is so large it almost acts like it is dumping out the tail pipe. It is pretty much a double straight through tube though so it really won't present much if any restriction anyway. From tailpipe to manifold if you can pick up 10 horsepower by making it free flowing I'd be impressed. I suspect any performance increase would be in the fact that you removed about 50 lbs from the truck lol. It doesn't make enough power to be that restrictive. Add 100 hp to it then I'd say there are gains to be had.
 
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Reprise

Lifetime VIP Donor
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Jul 22, 2015
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Well, as it turns out, I *do* have a plan for I/H/E - I've got the TBSS intake in hand, and headers on the way. Last is a mild cam / lifters.
I might be closer to (but still not 'at') +100hp when all is finally done. Maybe port the heads a bit, as well.

Always wanted to have a blower set up - but now I'm starting to seriously think about turbo. That's next year, though.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Two different engines being discussed and mods and increases dont really crossover much.
 

02trailblazin

Member
Sep 25, 2019
35
Florida
Ur right motor cant breath with stock exhaust but also on the stroking a 4.2 thats pretty much what it is a 2jz stroked by gm and built the american way and with that being done all motor unlike the 2jzgtte

If i can find the article i read ill post it for principal that it truth but they fig a crank the size a 6.0l would use and a piston the size a 350 uses so less 2 cylinders and being straight is why iy vets the power gains
 

02trailblazin

Member
Sep 25, 2019
35
Florida
I do know that the 06 4.2 exhaust ports are alot smaller then the header gasket
From factory only because i went to match port it to the gasket with stock manifold and i couldnt believe how small the 2 -1 exhaust valve size port was compared to the factory gasket and header so after seeing that my decision to buy a turbo manifold kit an weld it up has been dismissed because the stock manifolds good enough similar to a top mount log manifold ive seen jus gonna have to build it back to were it has to set but heres some.proof in the pic are head with gasket then head with gasket and header with out gasket and then gasket ontop of head and the stock 3 bolt flange on header measures 2 1/2 in while the exhaust piping opens to 3 before the first resinator and continures to muffler so i think head porting on the exhaust valves will significantly give u the most bang for ur buck and then go with a tune and intake i wouldnt worry bout the intake runners tho it looks like theyve already ported them to handled the ve airmass from the size crank am piston they used to get the ci of a v8 hense the engine family class its given
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
but heres some.proof in the pic
No Pic

the stock 3 bolt flange on header measures 2 1/2 in while the exhaust piping opens to 3 before the first resinator and continures to muffler
The stock exhaust is not 3 inch. It is 2.75.

crank am piston they used to get the ci of a v8 hense the engine family class its given
These are not V8 cubic inch and not in the V8 class engine family. Hell they are smaller 6's than the 4.3; which was actually a 350 with 2 cylinders sliced off.
 

02trailblazin

Member
Sep 25, 2019
35
Florida
Heres the pics
 

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