What does a LONG runner intake do for a turbo car?

[Stopsign32v]

Well my turbo 5.0 has a Performer intake on it. What would that intake do against say a box type or short runner intake on a 302 turbo?

[1fast-turbo-coupe]

ive always ran the box.

[Stopsign32v]

Anyone?

[65ShelbyClone]

Well my turbo 5.0 has a Performer intake on it. What would that intake do against say a box type or short runner intake on a 302 turbo?

It will help preserve some off-boost torque.

[twofast]

here's a dynograph against a performer and a downs box/gt40 lower. runs where on the same car within a day (same conditions). you can see where i lost 70 ft-lbs in the midrange.  i lost .2 and 2mph at the track with the box.
blue is the performer. red is the box.

[shootrmcgee]

This makes me wonder if anyone has done any comparisons with the spyper intake. It dosen't have a "box" to fill with air, nor does it have long runners. Curious...........................

[BlackMagic94]

here's a dynograph against a performer and a downs box/gt40 lower. runs where on the same car within a day (same conditions). you can see where i lost 70 ft-lbs in the midrange.  i lost .2 and 2mph at the track with the box.
blue is the performer. red is the box.

Well no shit.  You did not take advantage of what the short runner box intake is made for, RPM, if you had a different grind cam setup that was designed for a higher RPM range then you would start to reap the benifits of such an intake design.  But with keeping the same shift points, of course you are going to lose low and midrange power. 



Would you install a custom solid roller cam with a powerband ground for 4000-8500 rpm, and then shift the car at 5500 rpm? Well its the same damn thing. 

[shootrmcgee]

Good point.

[turbo'd88]

Well no shit.  You did not take advantage of what the short runner box intake is made for, RPM, if you had a different grind cam setup that was designed for a higher RPM range then you would start to reap the benifits of such an intake design.  But with keeping the same shift points, of course you are going to lose low and midrange power. 



Would you install a custom solid roller cam with a powerband ground for 4000-8500 rpm, and then shift the car at 5500 rpm? Well its the same damn thing. 

True but not everyone is going to be useing a big lift soild roller or even rev thier car to 7k-8500........so all in all if you are building a motor to rev high and make more power up top then a box is better but if it's rev'd til like 6k with a hydro roller then long runner is better it depends on your whole combo and goal

[rtz]

lost 70 ft-lbs in the midrange. 

Maybe it was more the GT40 lower causing it compared to the Edelbrock lower, more so then the box upper?

[twofast]

Maybe it was more the GT40 lower causing it compared to the Edelbrock lower, more so then the box upper?

no, there's been alot of people making big tq #'s with the gt40 intake (upper & lower).

[smokin03cobra]

i've been running a GT-40 upper and lower for about 3 months now and it worked great.  got my hands on a sheetmetal box type with same gt-40 lower and i HATE IT.  i lost all downlow torqure.  haven't been to the track yet to see an ET differece but by my SOTP Dyno i def lost some power

[rtz]

I was always under the impression that in a forced induction setup, box, long, or short runner upper intake would make no difference since it wasn't "needed" to help with the flow as in the way it is in a NA setup.

[twofast]

i thought the exact same thing.  i guess we're wrong.

[enyawix]

It will help preserve some off-boost torque.

+1
Short runners make crap power in the lower rpm ranges.

[rtz]

I'll have some dyno numbers here shortly that I will post to this thread so we can compare to the above graph and see how my box does on a stock motor...

[BOSs5.0]

You guys may wanna go to a book store and find 5.0L dyno tests.  It will at least show some back to back tests proving very conclusively that intake lengths have specific purposes.  No different than camshafts. 
Turbos can partially make up for shit parts that are mismatched.  It will not add flow to anything.  A junk head, is a junk head.   A 200 rwhp pile of shit can still make 400rwhp with 15lbs of boost.  Doesn't mean it is an optimized engine combination for the intended use of the car. 

[BlackMagic94]

Exactly, I run a box and love it.  The shear fact of not having that gay ass middle bolt on the Edelbrock intake and the the ablity to change valvecovers or fuel injectors without removing the intake is worth its weight in gold alone if you ask me. 



Who cares about extra low speed torque, i like to call that wheel spin anyways.  My car is faster with the box at the 1320 where it matters. 

[ash]

I was always under the impression that in a forced induction setup, box, long, or short runner upper intake would make no difference since it wasn't "needed" to help with the flow as in the way it is in a NA setup.

true to  a extent...
the air in the atmosphere is 14.7 psi..
when the piston is on the down stroke, the volume is increased, therefore the pressure decreases, and the atmosphere pushes the air in...
If we can get the exhaust ratio to intakes close as possible... eg.  boost 25 psi, and exhaust manifold pressure 25psi, doesn't the engine "think" it is  under natural atmosphereic conditions, BUT only more of it??
soooo, what ever is good  for a unblow engine , is also good for a blow engine...??
any other idea's ???

cheers
ash

[BlackMagic94]

Short runner intake plenums are great if you build the motor to take advantage of design.  Simply switching parts and not increasing the power band is not a good idea unless you want easy access to VCs and injectors. 

[Stopsign32v]

Would AFR 165 heads flow enough to take advantage of a short runner box intake?

[twofast]

i was using afr165's when those dynoruns were made.

[Stopsign32v]

i was using afr165's when those dynoruns were made.

So you basically had the same setup as I have now. Performer intake and AFR 165 heads. What size turbo was it? Why doesn't that setup hold power? Was it the cam? Because mine is doing EXACTLY the same thing except my power falls off alot faster than yours. Maybe its my cam? (My cam was a Jay Allen custom grind made for the N/A with a 100 shot)

[twofast]

i had an incon twin turbo kit and stock cam with 1.7 rockers.

[Stopsign32v]

lol thats sad that a stock cam would be better for the turbos than my custom cam.