View Full Version : Exhaust bore sizes

01-26-2012, 07:05 AM
Hey guys, I am currently fitting an sr20det into a 1972 mk1 escort.

Can you guys tell me how much flow does a sr20det need to make about 270hp? Also is the standard manifold and down pipe good or bad? Should I replace with aftermarket.

Ideally I do not want to go past a 2.5inch bore exhaust. So whats your inputs, this enough? (I am not all for massive exhaust cans :wtf:)

Oh and some pics to entertain you (and yes that is a s14a tunnell and interior):


When finished should be looking something like this with bubble arches, havent decided colors tho

Redirect Notice (http://www.google.ie/imgres?q=mk1+ford+escort&um=1&hl=en&sa=N&biw=1280&bih=907&tbm=isch&tbnid=rSJ7tSxI_2kEtM:&imgrefurl=http://www.comp.co.uk/gallery/details.asp%3Fgallery%3DEscort%2BMk1_0034&docid=3mh8IaD0XlFd7M&imgurl=http://www.comp.co.uk/gallery/pics/FORD%252520ESCORT%252520MK1%252520MEXICO%252520ML1 580%2525208X15.JPG&w=458&h=305&ei=PE8hT_qXIsyGhQeD5qnIDg&zoom=1&iact=hc&vpx=377&vpy=200&dur=775&hovh=183&hovw=275&tx=191&ty=47&sig=116037383730084260463&page=1&tbnh=121&tbnw=182&start=0&ndsp=20&ved=1t:429,r:1,s:0)

01-26-2012, 01:25 PM
nice. there were a bunch of those cars in the Philippines. 2.5 inch is big enough for 270 hp. i had a car with 2.5 inch that made 300 whp. please post pics when your done. i love old school cars.

01-26-2012, 04:54 PM
Will be few years before its finished but I will pop up pics.

These escorts have a great reputation in Ireland and the UK. I think a listening to this will explain why:

Ford Escort BDA on a gravel track - YouTube (http://www.youtube.com/watch?v=0orA-AaIiQY)

01-26-2012, 05:17 PM
Honestly, turbo engines like to breath...3" would be the way to go. Ditch the stock downpipe with an aftermarket one. You can push the stock T28 on that SR to what you're shooting for, at around 14-15 psi. Just a matter of having the right mods to get it there...might want to considering getting larger injectors just to be on the safe side (440s, maybe 550s), Z32 MAF and a tune.

01-26-2012, 05:40 PM
Cheers for the replies.

I want to keep this power very useable, do not want an engine that comes on boost very quickly at high revs.

Only reason I do not want to go bigger than a 2.5inch bore is because big cans do not suit the style of these cars and 2.5inch back boxes designed to fit over the live axle is readily available. Anything bigger would need floor mods over the axle. But the exhaust on this car will be very short, it is a small car and will only have 2 boxes including the back box. So there should be less restriction in that respect.

I have a sierra cosworth, which is 2l 16v turbo that is running 14psi and 270 hp in a 4wd car weighing 1300kg. That thing comes in hard at 3 k revs. But I have driven the same car with the same power that was tuned so much better for driveability. So I want to do the same with the sr.

That car the sr20 is in will weigh about 900kg fully laden, so needs to be controllable or else the car will be all over the place.