My plan is to get some headers that are 1 3/4" into a new cat (any suggestions here as to which one and where to get it?) and do 3" to 80 series flowmaster muffler. Now this is going to change the way my engine flows dramatically and I was wondering on my l98 what you guys think my peak horsepower and torque would be and at what rpms? It's my perception that when you do mods that affect mostly high rpm horsepower that you lose some amount of low end torque.. Enlighten me gentlemen. Thanks.

 

I'd honestly go with 1 5/8s unless you intend on doing alot of modding.

 

Yeah, 1 3/4" is quite big for a mostly stock L98. Just get some headman or hooker long tubes with 1 5/8" and you wont lose anything on the bottem end...you'll gain torque. You'll gain horsepower as well, but long tubes from what I know make more low end torque than they do high end horsepower.

 

Actually that was a mistake. My intentions are to go for 1 5/8"

 

any ideas on what kinda power that will give me on an otherwise stock l98? and at what rpm?

 

kinda hard to say. It depends on how many miles you have on the engine, how much power the engine has now, what other mods you have, and the list goes on forever.10-20 ft/lbs and 10-15 horsepower would be a good guess...no clue as what rpm though. Probably wouldn't change the power band too much, just give you a better torque curve. If you can get it dynoed before and after you get it done just so you know.

 

the long tube headers will give you more upper rmp horse power and you will loose some low end ft lbs. but the long tubes will work better,i dont no how many mods you have or if you are stock,if you are running single exhaust,then i would go with the 1 3/4,if you are stock and duels then 1 5/8,the more mods you have the more they will help,if your stock then you will gain about 15 to 20 hp

 

also my stock l98 ran 14.0 with long tubes it runs 13.70 with no other mods,thats with the 1 5/8 headers,if your going to run headers get the super coms,you may pay more but there i lot better