Future Mods

Hey guys, I'm thinking about getting a couple more MODs, but have a few questions.....

First I'd like to get a set of Ported Exhaust Manifolds. Problem is I dont think I would be able to get at the back bolts and I think they might break off. How common is it to break exhaust studs off on the 3800? I've got right around 100,000 miles. How much should I expect to pay at a shop to have my exhaust manifolds changed out?


Next mod I'd like to get is a set of rockers. ZZP lists a set of 1.9 ratios on their site and they say that 1.9's can be ran without any other upgrades (pushrods/LS1 springs/timing gears and chain) Is this true or do I risk possible internal engine damage or valve float? I also found some 1.8 rockers on w-body store.

What would you guys go with? 1.8's or 1.9's? Also, with these rockers, does this make my 3800 an interference motor? Just wondering.

First I'd like to get a set of Ported Exhaust Manifolds. Problem is I dont think I would be able to get at the back bolts and I think they might break off. How common is it to break exhaust studs off on the 3800? I've got right around 100,000 miles. How much should I expect to pay at a shop to have my exhaust manifolds changed out?

What type of PEMs Tim? You can go with Power Logs and you really only need the front bank which is where the exhaust bottleneck is. See link below. But nothing beats headers. :grinyes:

Click here (http://www.zzperformance.com/grand_prix/products1.php?id=208&catid=110)


Why a shop? I thought you were DIY capable on this type of job. I had no problems with the studs breaking off. Just use plenty of PBBlaster on the 13mm nuts before wrenching. Getting the bolts at the rear exhaust manifold /downpipe is a different issue but patience and plenty of PBBlaster will help.


Next mod I'd like to get is a set of rockers. ZZP lists a set of 1.9 ratios on their site and they say that 1.9's can be ran without any other upgrades (pushrods/LS1 springs/timing gears and chain) Is this true or do I risk possible internal engine damage or valve float? I also found some 1.8 rockers on w-body store.

Go with the real 1.8 or 1.9 high ratio roller rockers. I have the SLP brand 1.8 RR. No issues with valve float. Plus an easy install considering.

Yeah, I'm DIY, but I would be more apt to tackle this job if this weren;t my DD. The front only? I was also considering a zzp crossover pipe too. WHich is why I figured, might as well get the back one too. Maybe I'll start soaking the bolts and ask Santa for the PEM's for x-mas. HE HE. and yes, powerlog pems from zzp is what I was looking at.

No valve float with 1.8's or 1.9's? Do you have an upgraded timing chain and sprockets? What do you mean by the "real" ones? You mean the remachined ones? Or the completly aftermarket ones?

Thanks Bob! I knew you would by my go-to guy for this.

Definitely none with 1.8 but it depends on the type rockers on the 1.9 ratio. Normally you'll need 105 lb springs to reduce or eliminate valve float. But I am assuming you are referring to the ZZP modified ones which are OK but as I pointed out not the real thing. They are not roller rockers just reworked stock but the aftermarket roller rockers do cost more but IMO well worth it.

will aftermarket roller rockers produce more HP?

Of course. Either the ZZP modified or aftermarket RRs will increase hp. You will feel it in the seat of your pants and see it in track times. Also, the PCM module should be custom programmed if you use the 1.8 or 1.9 ratio rockers to take full advantage of the mod. Shift points for 6000 rpms to be safe and the rev limiter to 6,200 RPM. With a PowerTuner you can do a little better or experiment between 6000 and 6200 rpms.

A powertuner? Is this an interface I can use to plug my laptop to my car and adjust settings of my dhp pcm? Sorry Bob, not too smart when it comes to any electronics beyond simply tech2 scan tools.

just wanted to chime in real quick and ask a question about this. if you were going to be raising the shift points, and the rev limiter to around 6K RPM's, wouldnt you wanna get a cam too?

sorry...let me correct myself. just looked at the 1.9's on ZZP and it says they will not work with an aftermarket cam.

Why would anyone use high ratio rockers with an aftermarket cam? That would be a disaster. Due to the high lift of most aftermarket cams well over .500 these type rockers are not used. You use the equivalent to stock which is 1.6:1.

The purpose of using high ratio rockers not to exceed 1.9:1 is not having to use an aftermarket cam. Good bang for the buck with a reasonable hp increase, fairly reliable, little or no driveability issues associated with a hot cam, an easier install job that can be done in less than a day for a typical DIY person and no supporting valvetrain mods needed.