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Old 12-03-2007, 12:07 AM   #1
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Default My engine modification plan

Hey guys. This thread is an offshoot of my Series II L67 and 6 speed manual project...

http://www.bonnevilleclub.com/forum/...81338&start=80

A while back in exchanging messages with F14'* official tuner, Ryan of Sinister Performance, he referred me to David Norris for head and */c housing porting. I received the following email from him regarding building up my engine. I'm wanting to be in the 300-350 WHP range...

Hi Philip, thanks for your interest! If 300 to 350 hp is your goal then that is not a problem at all. A ported supercharger is a great upgrade as well as a larger throttle body paired up with it. This will lower outlet temps of the supercharger by making it more efficient which keeps detenation down and helps out a bit with throttle responce. I do quite a few housings for Ryan and we always match up a Northstar throttle body, custom adapter plate, and a ported housing for a bolt on package. Head porting is definately a great idea but is not cheap but I will give you some prices on that as well. The HP numbers you are looking for will be easy to attain but how much you want to spend and how and when you will be driving the car will be factors in which route to choose. The engine is rated stock at 240 HP. A 3.4 pulley is usually good for around 20 additional HP, a 3" downpipe another 5-10 HP, ported blower housing and larger throttle body 5-15 HP, ported heads 15 to 30 HP depeding on engine combo. With these mods alone you are going to be 300 HP no problem. Keep in mind the above is with a stock valvetrain which is great numbers for a V6. Now you have a few options for valvetrain upgrades that will really wake the engine up. The mildest upgrade is a set of aftermarket full-roller rocker arms. They come in a slew of different rations, 1.8 and 1.9 being the most popular. The stock rocker arm ratio is 1.6 BUT the rocker arms do flex and fall short of this spec where an aftermarket rocker arm does a better job of keeping true to its advertised ratio. I have used numorous sets of 1.84:1 ratio rocker arms from ZZPerformance.com with great results. A higher ratio rocker arms such as this is good for an easy 20 HP on a boosted engine as it will lower boost because of more valve lift and better flow which alone makes better power, plus you can even drop another pulley size or two to add even more power but a optimum tune is required for the smaller pulley to run safely. Your other option is to install an aftermarket camshaft which hands down will make greater power than the rockers will. I have run both of these in my own cars and proved the gains at the track with before and after testing and hundreds of passes down the strip. I tend to favor rockers for a car that longevity is a main concern and reliability, smooth idle and longest valvetrain life. A set of aftermarket rocker arms will cost you around $400. There are cheaper alternatives to rocker arms such as modified stock rocker arms with a 1.9 ratio but I dont care much for the idea as you still have a stock rocker arm body and a lot of extra stress and there is no roller tip on the valve on a stock rocker arm. They are only $100 cheaper and in my opinion not the best route to take. They where made as a cheap alternative a few years back as aftermarket sets were in the $600 range, but those days are gone. Aftermarket camshafts will definately gain you the best power, generally from 20-50 HP with a good tune. I have installed a lot of camshafts in the S2 3800 engines and have never seen a failure, but they also will require upgraded valve springs, valve spring retainers, a new timing chain set, and custom pcm tuning as well as raised shift points, raised idle speeds to retain smooth idle, and a slight drop in gas mileage. A cam setup will cost more but the power gains will offset it. If a smooth running engine is what you are after then I would leave the stock cam in it and think about a set of aftermarket roller rocker arms. 1.84 is the highest ratio you can safely go without having to upgrade your valve springs. Once you get to 1.9 ratio rocker arms you really need to use a stiffer valve spring to prevent high rpm valve float. The tradeoff is a stiffer valve spring puts more stress and wear on the timing chain and timing chain dampener so again I favor using a 1.8 or 1.84 ratio rocker arm in daily driven cars looking for a little more power. I hope I havent lost you in all of that so far! here are a few prices on my porting services.....

Ported supercharger housing with standard outlet porting - $120
Outlet porting for use with an intercooler - $140
Inlet porting for stock throttle body an additional $40
Inlet porting to 75.5mm for use with larger throttle body an additional $60
Custom Northstar throttle body adapter plate $75
Rough estimate on used 96-99 type Northstar throttle body - $75

For head porting I charge $800. This includes a complete valve job which is mandatory with an head porting regardless of what you read or hear. My head porting includes extensive exhaust runner work, teardropped valve guides on the intake, bowl and pocket work on intake and exhaust, injector bumps ground down inside the intake runners, gasket matched intake runners, polished exhaust runners after final blending.
To give you an idea of what head porting for this market costs a few of the 3800 specilist vendors charge between $1200 and $2200 for this type of work. I will also tell you that most of these heads that others sell have larger valves which while a good idea will cause a few possible problems depending on your valvetrain setup. One company for example uses aftermarket valves and different valve guides which have proven to wear prematurely and destroy your engine, not good! Another company uses an OE type LS1 engine valve which I will also use BUT the valves are longer and this requires carefull examination of valvetrain geometry during engine assembly and if not properly set up will destroy the heads and rocker arms. The 3800 engines do not use adjustable valvetrains, they rocker arms simply are torqued down and that is it so it is mandatory to check for proper alignment of the rocker arm hitting the valve tip or premature wear will result when using aftermarket heads with larger valves. I like using the stock sized valves unless it is a max effort combination that wasnt intended for lots of mileage.

I hope this gives you a good idea of some of your options and pricing to upgrade your engine to the power levels you desire. There are a lot of different combinations that work great, it just depends on how you want it to perform and how much you want to spend. If you have any other questions please feel free to ask.

David Norris


I don't doubt him or disrespect him, but wanted to know you guys' opinion on his suggestions. Would you do anything different?
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Old 12-03-2007, 12:10 AM   #2
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I'm open to camming my engine (stock from a 2002 Regal GS, about 52k miles) but will my valvetrain wear out quick? Not sure how I plan on driving this after, but the last season I drove it I put about 20k miles on the car (I'm on the road a lot). Will I have to rebuild my heads every year or something?
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Old 12-03-2007, 12:53 AM   #3
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I don't take exception to anything David has told you.
Good recommendations.
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Old 12-03-2007, 12:58 AM   #4
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Quote:
Originally Posted by 2000SilverBullet
I don't take exception to anything David has told you.
Good recommendations.
agreed,

and ryan has earned my trust as a great provider of customer service, and im sure he lead you to the right guy. with that mod list, ur goal is certainly attainable. and thats going in a reatta right? that will be FUN!!!
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Old 12-03-2007, 01:00 AM   #5
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Thanks so far. Ryan previously tuned my supercharged LN3 by mail so it was drivable and I made a day trip to him and he fine tuned it. The same is gonna be done with this project
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Old 12-05-2007, 12:59 AM   #6
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One more thing: what size exhaust piping would you guys suggest?
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Old 12-05-2007, 08:35 AM   #7
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You could probably go with a 2.5" exhaust and be all right. Just get a high flow cat and a moderate muffler should do. I don't believe our 3800s can outflow about 750 cfm. You'd have to break 7000 rpm to worry about exhaust pipe size, I believe.
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Old 12-05-2007, 12:16 PM   #8
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For a Series 2 breaking into the mid 13 second range many upgrade to a 3 inch exhaust. You may lose a little bit of torque, but the high end power increase will be nicely noticeable.
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