Has anyone tried switching from a TPI to an HSR or Mini- Ram with dramatic results? im runing a 355,23 deg.Trickflow heads,226-500 lift cam,P70 turbo(18-22lbs),3.42 gears,3200 stall,3800 lbs,with a bone stock TPI,car runs great,gone 11.5 in 1/4,just wondering how restrictive a stock TPI is on a Turbo application & if its worth switching to a HSR or other?

 

The stock tpi system is great for torque and not so great for horsepower where as the Holley Stealth Ram is an almost complete opposite

 

I would think the stock tpi is the limiting factor in you eng and with a switch to a higher flow intake I don't see why you would not see more power through out the rpm range.

 

not sure how this works how to post a thread or whatever but u might want to look at available "RAMS" in this forum. grumpyvette stated he worked with 5 different intakes and that the stock tpi has 200 cfms flow and ported goes 230 and a hsr flows 275 cfms outta the box and ported would go 300cfms. so u should see alot of gain from an hsr i would think........right grumpyvette???

 

CORRECT!
the HOLLEY STEALTH RAM FLOWS at 275cfm out of the box, can easily reach 300cfm with minor port work the stock TPI has a hard time flowing 230cfm even with minor port work, look here
most of this info is right off the accel,holley,edelbrock, and TPIS sites, add a little math and the results become much clearer!!!
GETTING YOUR Intake....... length ....... port in -- out
Stock GM Base--- 6.375"------ 1.47"- 1.96x1.2
TPiS base------ -6.125"------ 1.75"- 2.09x1.28
Accel base----- -6.125"------ 1.75"- 2.09x1.28
Holley base------- 6” runner 2.3”- 1.9”x 1.23 (2.337 sq inches)
Runners
Stock TPI----- -- 7.250"------1.470" round(1.70 sq inchs)
SLP ----------- - 6.625"------1.600" round (2.01 sq inchs)
Accel LTR------- 6.625"------1.615" round (2.05 sq inchs)
TPiS----------- 7.625"------1.660" round (2.168 sq inchs)
Mini ram -----3.5”
LT1 ----------3”
Runners (measured individually)
Stock....................203.17 cfm
ACCEL................242.02 cfm
Extrude/ACCEL...275.83 cfm
Super Ram............289.18 cfm
Intake manifold with 3/8 inch radiused intlet
.............................222.45 cfm
Holley stealth ram ………..275cfm
Stock intake manifold with runner
Stock....................198.72 cfm
ACCEL................213.52 cfm
Extrude/ACCEL....217.11 cfm
Super Ram............220.67 cfm
Holley stealth ram …..275cfm

ACCEL Hi-Flow intake manifold with 3/8 inch
radiused inlet.........251.51 cfm
ACCEL Hi-Flow intake manifold with runner
Stock....................215.83 cfm
ACCEL................232.53 cfm
Extrude/ACCEL....243.21 cfm
Super Ram............240.24 cfm
Extrude-Honed ACCEL Hi-Flow intake
manifold with 3/8 inch radiused inlet
............................275.83 cfm
Extrude-Honed ACCEL Hi-Flow intake
manifold with ACCEL runner
............................266.94 cfm
Edelbrock Performer RPM manifold
(Stock)..................286.51 cfm
Edelbrock Victor Jr.
.............................275.24 cfm

HOLLEY STEALTH RAM
Stock…………………………… 275cfm
Ported…………………………..300cfm
Runner lengths
Stock tpi manifold 8” runners 11.25”, cylinder head 6” total 25.25”
Accel super ram manifold 8” runners 7” cylinder head 6” total 21”
Holley stealth ram manifold 6.26” ” cylinder head 6” total 12.26”
Edelbrock performer RPM runners 6” ” cylinder head 6” total 12”
Edelbrock vic jr , runner length 5.5” ” ” cylinder head 6” total 11.5”


Now play with the figures in the calculators below, what youll find is that the if your using a 350 size engine as a guide BTW THE INDICATED Torque PEAK IS WHERE THE CYLINDER FILLING EFFICIENCY TENDs TO PEAK due to RUNNER CROSS SECTIONAL AREA,AND THE HP PEAK RANGE IS WHERE THE RUNNERS TEND TO BE MOST EFFECTIVE, DUE TO HARMONICS/INERTIA in THE AIR FLOWING THRU THEM THATS WHY THEY ARE SOMETIMES A FAIRLY WIDE RPM RANGE SPREAD. you can of course raise the tq peak with cam timing and porting and differant header designs but the harmonic range will tend to stay fairly steady in the intake ports, and yes increasing the displacement tends to lower the rpm ranges


the tpi runner length is ideal for peak tq 3427rpm and 2700-4000rpm for peak hp

the super ram is ideal for peak tq at 4032rpm and 3300rpm-4800rpm for peak hp

holleys stealth ram runner length is ideal at 4700 for peak tq and 5618rpm to 6282rpm for peak hp

the mini ram and lt1 intakes are ideal for peak tq at about 5200rpm and 7244rpm to 8101rpm for peak hp

now KEEP FIRMLY IN MIND the engines tend to enter valve float and get close to engine red line by 6300-6700rpm depending on your combo' after running all the available combos, Ive found a HOLLEY STEALTH RAM is CURRENTLY THE BEST CHOICE,ESPECIALLY IF MATCHED TO GOOD CYLINDERHEADS AND THE CORRECT CAM






http://www.rbracing-rsr.com/runnertorquecalc.html


http://www.bgsoflex.com/intakeln.html

 

Grumps, (Can I call ya Grumps? )

How far down do you think a 383 would shift those peak hp/torq ranges? I am thinking of taking my LT1 intake of my Formula's 350 and replace it with a HSR then use the LT1 in my vette with a 383 and super charger and a 222/230 .540/.560 cam.

Thanks

 

Wow looks like Stealth ram wins hands down. I like the CFM numbers. And its the cheaper of the bunch next to stock. Go figure.