ok, thanks guys. I thought going with 3" all the way back to before the gas tank and then splitting to 2 pipes of 2.25/2.5" to the mufflers would be effective. Is a better solution to go 3" right to the mufflers and do you know if there enough room to do this? Are there mufflers available with 3" intakes? My resonator is falling apart so I thought I would try and put a straight pipe back. I can always put a res back in if it's too loud.


with the mods I am doing, any suggestions on an exhaust set up to maximize HP and performance?


Ohara, since Will has moved to B.C. he said to let him know the final mod's to be done and he will program the pcm to send me. Then I return mine to him. I hope this works. I've heard good things about him.


Thanks again for your assistance. The last time I did any mods on a stock car was on my '71 Cuda I owned from new so it's been a while but I am excited to give my Monte an extra kick.

 

No cutting back down the exhaust to 2.25 will cause a restriction in the exhaust flow. Keep it 3 in from downpipe to mufflers, you can buy the mufflers in the 3 in.

Like I said with our cars the exhaust doesn't do too much performance wise, you will mainly want to improve for longevity ie stainless so it doesn't rot out and sound, I suggest you search you tube for exhaust sounds on your car as there are lots of them posted on there and it will give you a good idea of what you will have on yours.

If your resonator is falling apart, you have options to replace if you decide to do so, some members have installed a thrush glasspack in place of the resonator, completely delete it, or zzp offers some other options on their website as well such as magnaflow and their house brand, so like you said if you do decide to delete you can always put one back on.

They also sell catback exhaust systems on zzp that you may be interested in depending on how much you have to spend on your upgrades, as honestly I would just get the downpipe and mufflers done as cheap as possible with the best you can get cause you really aren't going to get that much of a gain from it. The supercharged motors really should have a 3 in exhaust all the way back as they push more air through the motor with the supercharger. Here is a link to a post a member posted for modding our cars, it has a lot of information and will give you a great idea of what you will gain from each mod and help you determine what approach you want to take to get the end results

https://montecarloforum.com/forum/fw...n-3800s-10942/

I had Will tune my car and he is a great guy, went to his house and met his family and honestly can't say enough good things about him. I'm very happy with what he did for my car and highly recommend him

 

Mine is a 3" crossover pipe, down pipe, high flow cat and 3" also all the way to the muffs. Sounds awesome to me. Put some Magnaflows on

As O'Hara states necking down to 2,25 is like putting a step down adapter causing more backflow to build up. All this exhaust begging to let me out and you closed the door 3/4" on a3" door to a 2.25

 

good info guys, thanks. it was actually a mechanic friend of Will@overkill that suggested the 3" drop to the dual 2.25" before the gas tank configuration. If that defeats the purpose then i will price out 3" all the way from the exhaust manifold to the muffler tips. not cheap I'm sure.


If I go 2.5" all the way would I lose much hp/performance/sound?


I did read the stuff at the mod link on Bumpin's recommendations. Going with the downpipe/muffler system along with CAI, 104 plugs, 180 tstat, pulley drop to 3.4" , Will's PCM tune.


I am also going with 1.9:1 rockers but still have a question on this one. regular rockers vs. roller tip rockers?? roller tip are supposed to be better/less friction but are they worth double the price, any additional HP/performance gains? Should I also upgrade/replace the valve springs suggested by one supplier with either option? I have 72,000miles/115,000km on my Monte.


one last mod question, is the PLOG mod worth it? if i go that route i would have it coated first.


I will finalize my parts list by Friday, as i am going to the States for a week of golf and will have everything shipped there. saves me duty/taxes/shipping to Canada.