New Bosal front pipe: smaller diameter???

[Nervous]

Just compared the new Bosal front pipe bought at rockauto.com, Part no 0993251 and found out that it has smaller diameter pipes!




Catalytic is smaller too, btw:


Are there any problems because of this and I need to return it? Or, just install and forget?

[71Corolla]

That doesn't seem right at all. If it was me, I doubt I would install that. Seems odd they would use smaller diameter pipe though right? Maybe the overall back pressure is the same?

[Nervous]

I measured diameters, btw.
OEM, at headers - 4.5 cm (1 3/4"), at cat - 6.5 cm (2 9/16")
Bosal, at headers- 4.4 cm (close to 1 3/4"), at cat - 6 cm (2 6/16")! WTF? How is it "direct OE fit"?

[Gibson99]

1mm is trivial at the headers, and really, considering the overall ID, 5mm at the cat isn't much either. also, catalyst technology has improved in the last 15 years, so it's ok that it's smaller. the matrix inside may be longer than the one in your old one. i wouldn't worry about it.

it's direct fit because it's pre-bent, and has the right size flanges in the right place/orientation so you can just bolt it on.

the thing i noticed was the lack of heat shields in several places. then again, my JPP headers/y-pipe don't have any heat shields on them either - the shields are on the car itself.

[Nervous]

So, you think it is ok to go ahead and install it?

[bigbird]

looks fine, unless your goin for performance the bosal OE replacement parts have never had any complaints. as long as teh flanges and bolts line up your good.

[Nervous]

Thanks! I am not looking for performance gain, but I don't want to lose it either. But if you think it is ok then I m good to go.

[THEARCHITEK]

yeah on my 2.2 i broke my flex pipe and i replaced it with bosal n it actually was smoother then wen the original was in shape

[Nervous]

Well, the 0.5 cm smaller diameter of the pipe at the cat is crucial. I just can't insert the front pipe into the flange because of this! The O.D. of the pipe in the flange is exactly 6 cm, the same as I.D. of the new front pipe. It just doesn't go in! F@##! I am so pissed and disappointed by bosal! I am going to send that crap back to rockauto and get a magnaflow front pipe. So much lost time!

[Rickrpose]

dam man sorry to hear that.

[Nervous]

Thanks... Even if I hammer it in to the flange (see pic below) - there will be no space for the gasket What Bosal was thinking about?????

[73sport]

Not that this helps any, but IIRC Jason's 1MZ California spec header pipes where all smaller ID than typical but this could be year change vs state change too? Did the R-auto specify anything like that? I mean a 95 MZ Wagon, how hard is that? I hope they do good for you on the return and correction of this. . .

That sucks. Sorry.
I hate when we're primmed to get something done and the parts don;t fit! I can relate. Prolly not cheap to ship that either.

Edit: just my 2 cents, but in the case of collector pipes fitting inside of header pipes, the reversion caused by the smaller ID on the collector is BAD. It makes huge turbulence not to mention the loss of sealing area for the gasket. It really should be snug fit or in other application go the other way such the the small opening dumps into a larger opening.

[Nervous]

Thanks, 73. Rockauto states this part is for federal emission, sedan/coupe/station wagon, exactly my case. And this is, unfortunately, not the first time when rockauto sells wrong part. Previously I bought a LEFT A/T outer shaft seal and they sent me the RIGHT one (right is smaller; left is bigger). They returned me money, but didin't returned shipping, however that was clearly their fault). But I still like rockauto anyway!

[Gibson99]

Originally Posted by Nervous

Thanks, 73. Rockauto states this part is for federal emission, sedan/coupe/station wagon, exactly my case. And this is, unfortunately, not the first time when rockauto sells wrong part. Previously I bought a LEFT A/T outer shaft seal and they sent me the RIGHT one (right is smaller; left is bigger). They returned me money, but didin't returned shipping, however that was clearly their fault). But I still like rockauto anyway!

nervous, you're way too nice. if they shipped me the wrong part and tried to charge me shipping, i would have disputed the charges with my credit card company and bought the part somewhere else.

Now if *I* ordered the wrong thing and they shipped me exactly what i ordered, then yeah i have to eat the cost. But when THEY screw up and they try to make YOU pay for it? uh, no thanks. You'll be hearing from my CC co, and I'll be shopping elsewhere.

[Nervous]

Heh... Yeah, I'll contact them about this issue with providing photos and measurements, will see what rockauto will say. My Magnaflow front pipe is arriving tomorrow from Amazon ($320 shipped), will compare with it too.