header and downpipe question

Jbucky05 · Post by **Jbucky05** » Fri Dec 12, 2008 1:59 am

so i just recently installed my srt exhaust. and i am looking to get more gains from the exhaust depo. i am soon to purchase a 60mm tb and a iceman intake, so my question is what is the best downpipe and header to buy. i have read that an magnum header is very good for a 2.0 L non mag ....lmk what you guys think...looking for the best possible gains. ( and i know NGC dont allow much but any is again hopes are not to high i have come to expect and appreciate little lol)

Adionik · Post by **Adionik** » Fri Dec 12, 2008 4:09 am

Don't spend more than $100 on whatever you choose, of which i'd probably suggest an R/T. The gains just aren't worth the money.

Cabbs · Post by **Cabbs** » Fri Dec 12, 2008 5:31 am

You have to be careful with the 60MM TB, the computer may or may not like it.

patiofurnituregt · Post by **patiofurnituregt** » Fri Dec 12, 2008 6:02 am

Correct me if i'm wrong but isn't a 60mm TB a bit big....cause I would imagine a 55mm will flow plenty of air (at higher velocity too) especially for most n/a 2.0l.

I thought I remembered racer12306 doing some dyno comparisons that showed what TB made the best power for a mag.

gilly02le · Post by **gilly02le** » Fri Dec 12, 2008 6:53 am

Quoted From AllPar.com/neon/performance

Gary Howell wrote:

"49mm TB flows 252 cfm
52mm TB flows 283 cfm
55mm TB flows 317 cfm
60mm TB flows 377 cfm

At 8200 RPM a 122 cubic inch engine will need 290 cfm at 100% volumetric effiency, using the formula ((Max RPM/2)*Displacement)/1728. Rule of thumb is to go 10% over because a naturally aspirated engine can go above 100% volumetric efficiency because of cam overlap, header design, etc. Go above that and you kill low end because of reduced velocity, go below that you starve the engine for air at top end. 110% is volumetric efficiency is 319 cfm."

Based on this, 55 mm does seem to be the option for naturally aspirated (non-turbo) engines.

However, i do have a 60mm TB on my neon, which is atx for the time being, and I can say that i definitely did not feel any loss in power down low. If anything i got a some back, my car accelerates much easier now, which is nice with the long gears of the 4-spd slushbox.

Post by **racer12306** » Fri Dec 12, 2008 6:57 am

nah, it wasn't me with dyno numbers.

Jbucky05 · Post by **Jbucky05** » Fri Dec 12, 2008 7:25 pm

so a r/t header and downpipe would be the best route? and i forgot to mention that i do plan on going with a mag intake manifold soon...

Post by **occasional demons** » Fri Dec 12, 2008 8:53 pm

If you do get the CEL with a 60 mm, there ia a 56 mm option, tho you need to fab an adapter to mount it to the IM....

occasional demons wrote:While working out a project with BRR I noticed something with the Ford V6 TB, which BBK sells in a bored out version. The neon TPS will bolt directly to it. The only mod needed would be to the throttle shaft so the neon TPS slides over it.

Notice how the mounts are 90º to the gasket surface? The 65mm is 180 ishº, so if you want to spend for the BBK option it is damn near plug and play. This may be one option for NGC, if your's don't like the 60mm TB.
http://store.summitracing.com/partdetai ... toview=sku

Edit: just a reference shot...

The smaller one is 49mm ish.