my 75 toyota

On my 88 i put a Pacesetter header on it. Had the new o2 bung welded to the pipe on the collector. Now looking back after they installed this i notice the pipe size is 1 an 7/8 diameter. as the collector came with the header i wanted to run 2.25 all the way. So am i able to leave it 7/8 then bushing up to 2.25 for the rest or will that bottleneck the exhaust in the 1 fooot peice of smaller pipe. Or should i have it cut off and find a 2.25 collector and start over. Just wondering how much differcecne in the 2. Amy takers

ksti

Well it was me I would start over because it would be in the back of my mind always bugging me. I dont know what out of pocket $$ you have spent so far, but I would just want same size all the way. Hope you work it out.

grotto

Don't know who "they" are but if you told them to use 2.25" and they used 2" instead, I'd take it back to them and tell them to make it right.

my 75 toyota

well it has 1 an7/8 all the way till get the money. How much of a power difference will i see going from a 1 an 7/8 to a 2.25 and a flow master 40

abecedarian

1 7/8 from the header to the converter, then 2.25 out to the flowmaster?

You're not going to see any real significant if even noticable difference.

abecedarian

It's a 4:1 header, or 4:2:1?

If 4:1, you'll probably not even notice a difference if you went 2.25 into a 2.25 converter (Magnaflow) and 2.25 out to your flowmaster, and maybe even a "loss".

my 75 toyota

Opps no the entire exhaust from the header all the way back is currently 1 an 7/8 . I want to upgrade to the 2.25 from header collector back and put a flowmaster 40 on it. I was wondering if i would notice ant change in it then

abecedarian

If the outlet of the header is 1.875" (1 7/8) and the inlet to the converter is the same, you'll be best served leaving the header to converter the same through then step up to 2.25 after the converter.

my 75 toyota

The outlet of the header is not that the collector ids also a reducer down to 1an 7/8. so yes i can change the collector to a 2.25. that i have already checked

my 75 toyota

just wanted to know how big a difference going from 1an7/8 to 2.25 would do

abecedarian

On my 88 22re, I'm running stock exhaust manifold and downpipe into a Magnaflow converter with 2.25" inlet and outlet, into a Magnaflow muffler with 2.25" out the back.

I can't say it made a huge difference, but when the muffler was installed I also went from 28" tires to 30" tires and the exhaust didn't help much. Later, after a smog test and the converter was replaced with the Magnaflow one, which coincided with a tire change to 31", it picked up a little bit of torque- on the same roads I didnt have to downshift as soon as I did prior to the new converter (and new tires), but still had to downshift.

A lot of how your engine responds to a header and new exhaust will depend upon how you tune it, your valve adjustments and such.

I can't help you more than that.