MRGSL-SE

Since its a twin turbo and no actuation is required does it still require a back pressure to open up something... I always thought that a FD might need it for some reason...

93BlackFD

nope

Mahjik

iTrader: (1)

Backpressure helps control boost with a stock/un-ported wastegate. However, if you have an aftermarket or ported wastegate, then backpressure really isn't an issue.

duboisr

No back pressure == faster than dirt , or faster than the speed of water . Second gen 6 port motor needs alittle to open the ports when stock .

Houdini

iTrader: (3)

as long as you can control boost, the turbos should give you plenty of back pressure

skunks

yep, no backpressure is required!

T88NosRx7

iTrader: (1)

back pressure is the enemy

$-£fînî-$

in an automatic fd is important backpressure???
i think is good for better boost response or lag???
thanks

Donovan

Less backpressure= less low and midrange but more high end power.

poss

iTrader: (5)

on an NA motor

on a *typical* turbo motor, you are going to see less low end, but improved turbo response, improved mid, and improved high end power.

Railgun

Stick your finger up your butt. Like it? Neither does the FD.

Donovan

http://www.efini.net/tqcomparo.htm

widebody2

what happens if I like it??? Oh...Did I just type that out loud????

ijneb

Then you are a SICK person

Donovan

look at this link. It shows some info on backpressure and it's relationship to hp and torque.

http://www.efini.net/tqcomparo.htm

Tomco78

Then I have a couple of questions:
-How much work is it to remove the WG and have it ported?
-Is it possible to buy a lager wastegate for the stock turbos? One that just bolts on in without major modifications?

KevinK2

wael had ign problems with that midpipe run, between transition and 6k rpm.

better to compare the hi-flo cat run to his old dyno run, with midpipe and no misfire.

airborne

did he? i notice that little extra hump in the graph but the hi flo cat run had that too. i was there when he did it and he didn't mention anything then. what kind of problems?

KevinK2

The graphs were discussed extensively on the 'big list' when he 1st posted them .... mid pipe = no torque, bla, bla.... Having seen many dyno sheets for mid pipes, I posted that his mid-pipe run was not typical, and obviously had an engine problem between transition and 6k. Don't recall exactly, but he acknowleded either a plug or ignition problem had occured there.

just look at the "333 ft-lb" link on that page, for what a midpipe run should look like.