New IC Pipe

[GC89]

I just picked up spearco and plan on running all new IC pipe on my 89 in the near future. I recalled the sticky about flow rates in the 7m. I figured I's see if my plans to go to 2.5 were on par. The numbers were not what I expected. You want to be pulling a velocity of 300fps in the main part of your power band. I plan on running about 8-10 psi, but can see myself stepping up to 12-14 down the road.

These were the results

It will probably be a while before Im serious about going to 12-14psi. I never thought that 2.5" would be too big? Especially when some people run 3". so it seems 2" is the best at 10psi and 2.25 at 13. So stock really isnt too small after all. I still want to re do it to get rid of the restrictive bends and shape changes. I must admit running all new piping that small does seem silly but I guess the numbers dont lie, what do you guys think?

 

[crrider80]

Beautiful research. I tried figuring out what those numbers meant but I'm not too comprehensive. I do believe that the numbers don't lie rather than the "ass dyno."
-Steve

 

[GC89]

Its good to know but Im a little dissapointed that 2.5 would actually do more harm than good:icon_frow I already picked up a few pieces to start working out my set up

 

[spoolint78]

i guess it also depends on the size of your turbo

 

[Poodles]

all the math in the world can't compare to real dyno results...

this has been covered many times before, and the numbers from the dyno don't lie...

 

[7MGTEsup]

Its good to know but Im a little dissapointed that 2.5 would actually do more harm than good:icon_frow I already picked up a few pieces to start working out my set up

The 2 1/2" will not hurt your peak power but will affect your torque lower down the rev range. Depends on what your looking for. A big number on the dyno, or tractability on the street.

 

[bowsercake]

all the math in the world can't compare to real dyno results...
this has been covered many times before, and the numbers from the dyno don't lie...

I haven't seen the dyno sheets comparing 2.25 and 2.5 or 3 inch intercooler piping. Has anyone dyno'd where they only upgraded the piping? I've seen sheets where people have done a lot of mods but never one just comparing the piping.

 

[jtran8]

I agree with SPOOLINT78 , It all depends on the size of turbo . I have 57trim ct26 + clipped , i just went from 2" hard pipes to 2.5" hard pipes and i feel the different ; turbo spool up quicker at lower rpm . I'd say 2" hard pipes are good for stock turbo ; 2.25" hard pipes are good for 50-57trim and 2.5" hard pipes are good for 57trim and up.

 

[GC89]

Well for now Im leaving the ct-26 in there as it has no shaft play but I would love to upgrade my spare to a 57 in the future. Shes just going to be a street car with some balls and I would like to keep all the low end I can. So maybe 2" or 2.25 is the way to go for now. The out put on the ct is 2" so with it stock I wouldnt think bigger piping shouldnt do that much anyways.