Well, looking at guys like ST that make over 400WHP with the stock exhuast, it does beg the question how much power going to 3" makes and what restriction is it. I am surprised there are not many dyno results from people about the product...

 

yes, thats why they last so long,
Tony

 

That's a pretty lame argument. Just because it's possible to make xxx whp with a stock component doesn't mean that there is no gain in replacing it with something better. If ST made over 400WHP with a 2,5L then there is no need to build a 3L, or is it??

Concerning dyno results I haven't seen real back to back dyno results for that many 951 performance parts yet.

Tomas

 

Its not a lame argument, I am saying that its possible to achieve high HP figures with the stock exhaust, not that there are not benefits from it, but questioning how much of a restriction it is in the system. I dont know the benefits, thats why this thread exists. And you are right, there is no need for a 3.0 if you goal is 400WHP... but it depends on boost level and where you want the power range and whether its for long periods of track time for example.

 

The exhaust is a restriction, same as the air filter. XXX amount of HP is available through most bad configurations but at the cost of a higher boost level.
So it's impossible to rate these things at a certain hp-level. If an air filter is rated at 400 hp, it's not like it won't flow for 402 hp.

The less the restriction, the less the turbo has to work to overcome the pressure differential. But if you turn down the boost level to match the boost before the modifications the amount of HP might not differ a lot. But the positive effects of the turbo working more efficiently can be found in more places than on a dyno chart.

BTW regarding ST, he also reported a massive gain switching from his stock exhaust to the Lindsey 3".

 

Do you know what that gain was? I wonder why he does not run it now... I assume that was not with a 3" downpipe and was with the tapered Lindsey "3"" exhaust?

 

Search is your friend, my friend
https://rennlist.com/forums/944-turbo-and-turbo-s-forum/173276-sideways-at-100-mph.html


Rust!?

 

Sorry Duke, I should have searched... my bad. Much love brother...

lol yeah rust could have been it! What do you think of the aluminum idea?

 

Hmm interesting, a 7 pound drop in back pressure at 24psi. Considering John does not make turbos with more than 1:1.5 back pressure ratio, thats very impressive.

 

lol!

I supopse the 7 pound back pressure is the exhaust back pressure and the 1:1.5 pressure ration is the exhaust port to turbine back pressure.

 

ST original exhaust had many problems, from bad welds, to a terrible cat-bypass pipe. The exh. back pressure (turbo-to-head) was terrible (2:1). ST went to LR 3" exhaust and was able to lower the back pressure to where it performs nicely.

 

I had different set ups on my car. Went from stock to 2.5 inch Bursch testpipe with stock muffler and was really impressed. That's where the gains are coming from. Meaning when somebody compares stock to whatever they offer, the gains are often coming from the cat removal. After that I tried the full (yes, full inc. downpipe) SFR and the Lindsey one (stock downpipe and 3 inch thereafter) and all I have to say: they are loud but VERY disapointing when it comes to performance.

 

I have to say honestly, that the Lindsey 3" is a nice piece - I put the damn thing on in 45 minutes too.

I had 1:2 with stock exhaust - I lost 7 PSI backpressure with 3 inch.

 

So why did you take it off Jim?

 

Take off the lindsey? I didn't take it off.
I am thinking about putting a Borla in place of the Flowmaster, though.