I just got a 95 crew Obs and wanted to improve air flow. Is it good to have no cat and muffler and people telling me three inch down pipe then four inch all the way back from there is it safe to run it all open like that.

 

Yes. Many of us run straight pipes. 3" DP to 4" straight will sound and perform great.

 

Awesome any recommendations on what to do about the stock intake

 

Yep, 6637 from Riffraff.....Riffraff Diesel: RDP 6637 Filter Kit

 

^^^x2 on both of those. I've done them both and both made a big difference in their own right - and were quite easy to do. the 6637 especially.

my exhaust is 3" DP to 4" straight pipe through a 4" ID straight through muffler with a 45 degree bend and straight pipe out in front of the passenger side tire. the muffler is only there because its required by PA law - its not really doing anything though as intentially installed it with the louvers pointing the wrong way :-) the turbo whistle is still great and power is noticeably increased over the 3.5" straight pipe system what was on this truck when i bought it.

and, in turn that 3" DP to 3.5" system was much better than the stock crush tube to 3.5" w/ cat, no muffler straight pipe system on my old truck.

 

anyone tried to put an intercooler on the obs. I was just asing because my brother told me it would help, any kits o them as well?

 

I would recommend to not worry about an intercooler. It sounds like you are just getting started putting mods on your truck. There are several things to spend money on before worrying about an intercooler unless you are pulling very heavy loads all the time. An intercooler does not give you any more measureable horsepower, it does cool the air so that the exhaust gas is cooler helping to keep your truck running cooler when under heavy load. So unless you are pulling more than 12k for long periods of time then I would not worry about it.

 

Completely agree. I'm over 360hp and have yet to install my intercooler. I also pull about 10k, just gotta keep an eye on EGT's and boost! Lol

 

cool thanks for all your advice this forum has been very helpful.

 

how did you get the three inch to fit seems realy tight spot

 

Gotta do some work to the firewall to make it fit. a BFH or a big pry bar works well.

 

Or if you get fancy, a porta-power

 

I've got a 3" dp going to 5" straight pipe to a single 5" stack and I freakin love it! Sounds great, looks great, feels great!