Engine/Transmission (1998.5 - 2002) ats exhaust manifold performance??

[RAndrae]

Has any one dynoed or seen definate results from an ATS manifold either on a 12 or 24 valve. lower exhaust temp-- faster spool up-- more power?????? thanks

 

[Chipstien]

It would be a waste of money to buy a ATS manifold for the performance gains. However, if you crack the factory manifold then it would be stupid "not" to get an ATS to replace it.

 

[fox]

I just finished my ATS pulse manifold install last week.

I am sure it spools quicker. See my sig . I have had some heavy smoke off of the line and had to drive real easy to keep the smoke down. I even tried a hx35-14. It would spool quicker but quickly got hot and the kool down was long. Went back to the hx40 and will live with the little smoke I have on a quick take off. I just drive around it. The 40 will stay. It does feel a little more powerful but I did not dyno it.

My opinion, if you need DD II injectors you are in need of more air/better air.

 

[RonA]

I just installed an ATS manifold on my motor. I had it ported by Dave Miller(hdm48). I recommend having it ported if your looking for egt reduction(or hp).

RonA

 

[Mad Bomber]

Porting

Originally posted by RonA

I just installed an ATS manifold on my motor. I had it ported by Dave Miller(hdm48). I recommend having it ported if your looking for egt reduction(or hp).

RonA

Dave does a wonderful job. He also did the turbo too.

 

[favord]

FWIW, I installed the ATS manifold and like others can't keep the supplied bolts tight on the thing - especially 1 & 2. Lost one all together now. Called ATS and was recommended to go back to using 8 of the OEM bolts/bushings on 1, 2, 5, and 6 where there is enough room to do so and use the hex heads they supplied on 3 and 4 where there is no room for the bolts/bushings. Of course I've already tossed my old cracked manifold - bolts and all - so will go buy new ones and give this a try.



Haven't noticed a thing in terms of EGT's or spool up.

 

[rblomquist]

First off I totally agree with the above post reference not buying if your stocker is not cracked yet. Although the ATS is an excellent design and does flow better [IMO] it's not worth the coin if you still have a functional manifold in the truck.



As for studs backing out.....



The shop I had install mine asked if I wanted to put their "special" washers on the studs during install. They swore they hadn't had 1 truck come back because of loose or missing studs while using them.



I've had mine on since last november and not a one has come loose yet. Before I was having the stock studs loosen up all the time. What they use is a kind of flat washer that is made to go in a pair that "lock" together by means of a notch in each washer.



I don't know why it works so well but I can tell you is that they work.

 

[fox]

I have had my Pulse manifold on now for a week. Just got done checking it and all bolts are tight.

I used double washers and Blue Locktite.

With my truck I believe there is a performance improvement. Definately less smoke issues.

Wish I had dyno'd it!

 

[Gary - K7GLD]

Wonder why no one drills the manifold bolt heads, and then safety-wire them to keep them from backing out?

 

[RonA]

Gary.

I'll take a picture of mine and show these some of these young guys how to do that. I use to own a Dunstall Norton motorcycle. You could not survive without safety wire.

RonA

 

[rblomquist]

Originally posted by Gary - KJ6Q

Wonder why no one drills the manifold bolt heads, and then safety-wire them to keep them from backing out?

I was going to do that but so far no backing out with the double locking washers.

 

[Gary - K7GLD]

Like to see that Ron - it's a common aviation practice - it's REAL embarrassing to have parts falling off yer plane at 20,000 feet and 300 mph...

 

[OTRPU]

Hey guys, I gotta theory as to why the bolts back out. First was told was because the supplied new bolts were too long and bottomed out and this is why they backed out. So on my new engine my DOC used the really expensive thick gasket. Was supposed to solve my backing out problem. Well, I just looked in the engine bay and #5 top bolt was backed almost all the way out. I'm wondering if those having the backout bolt problem are like me and have the PAC brake? Or really any exhuast brake would probably do the same thing. I run alot of mountains with trailers, hence I'm constantly using the exhaust brake. Think there's anything to the idea that the increased backpressure is actually causing the bolts to unscrew? I had mine crossdrilled months ago, when they redid the engine they figured the thicker gasket had solved the problem. I'm safety wiring mine again. On the road the big problem is when the bolts back out, makes a big leak in the exhaust system, filling the engine compartment with soot. . . then that fabulous AFE filter just sucks in and traps all the soot. Tain't long affore the engine is trying to suck the AFE into the intake. Wasn't any sign of plugging, in fact just had the filter serviced before I left last trip, thing is totally plugged now, and I'm loaded. . . sitting in Lodi, CA Flying J restarting my hours again. Can't drop the trailer and go get it serviced, can't go another foot or chance the dam thing imploding. Need a diesel wrench that is close to Lodi, CA. . . fast. Wondered where my boost went and why EGT's were a climbing much more rapidly. I've been climbing hills at 45 MPH to keep the temps in range.



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Cheers,

Steve J

 

[rweis]

If you do a search, you will see what I did.



EXPENSIVE!, but works very well.



RustyJC has the answer. He KNOWS what is happening, and how to fix it. He is in a business that has the same problems of fastener elasticity etc.



I have checked the torque on mine once and will again in about another month. Last check was exactely where it was suppose to be.



I run an exhaust brake as well and tow a 13k 5er about twice a month. Pre EGT's are generally around 1000* - 1250* (1250* I get my foot out of the go pedal)



Towing heavy really is not the issue, an exhaust brake is not the issue. Understanding metal stud or bolt elastic and plastic properties is the answer and at least one solution is in the threads.



Bob Weis

 

[Gary - K7GLD]

Sure seems to me that STOUT lockwashers to maintain tension, combined with safety wiring would do the job pretty easily and cheaply...



But I'm just a farm kid/shadetree mechanic out here in the sticks...

 

[rweis]

Gary,



I tried the lock washer approach. The temps took the tension out of the lock washers in about a week.



Maybe a higher temp resistant lock washer or something.



I saw the problem is the ATS bolt goes plastic and can't return to its orgional length.



I think the OEM bolt and sleeve can because of it's longer length and the sleeve absorbes some of the heat so the bolt does not have to stretch as far and can remain elastic. The idea of using the OEM bolts where you can is probably a good idea. I would safety wire them though or use the OEM ss keepers on them like they do OEM.



Since the ATS boss is thicker it probably will grow a little more, but the orgional bolt might be able to handle it.



The Belleville washer approach was $37. 50 per stud. If you only did 4 studs it would be $150.



Bob Weis

 

[Gary - K7GLD]

Bob, what about the type of lockwashers commonly used on exhaust manifolds like the small-block GM gassers - those seemed to hold tension well - I think I even still have some out in my junkbox...

 

[rblomquist]

I'll find out what kind of lockwashers my shop used and post back. I haven't had any heat related issues even with the 100 degree + ambient air temps here in Vegas piling on for good measure.

 

[rweis]

Well, whatever works and holds the corrrect torque.



What is the correct torque anyway? I think the OEM bolts were 32 ft #. That pushed my first set of studs way into the plastic range. Then I found out that the torque for my configuration should be 16 ft #.



What torque is right for the ATS cap bolts? Has anyone actually figuered it out? Are the cap bolts really bottoming out?, has anyone actually measured them?



There is an equation for the elastic limits for bolts and has diameter, length, kind of materials, what you are trying to hold and its thickness, and kind of materials, and temperature range, and what the prestress of the holding device is and I don't know what else that feeds the equation.



I know where I got my figuers and why I did what I did. Someone else will have to figuer it out to whatever their configuration is. I do know there are still threads like this one about the ATS cap bolts not holding torque. Now the question is WHY?



Mine stay put, all 12 of them, and at the torque I set them, and they were checked after 3 months and will be checked again after 6 months.



Like I said at the first, whatever works.



Bob Weis

 

[nfox]

ATS Manifold

Did any of you guys coat your Ats Manifold? I was wondering if anybody tried the POR-20 to see if it holds up under high heat or if it flakes off?