Do the fords ahve ****ty top end just like our tpi's or do they have decent top end

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1987 Trans AM GTA
305 5SPD
Hypertech airfoil
gutted maf
kn filter
High Flow Cat,
3"Walker pipe
Dynomax Super turbo Muffler
TB Coolant bypass

"Three of the scariest letters you will ever see GTA"
Take a good look you won't see em for long

 

They have decent top-end, with some mild mods they can pull over 5k easy and with a cam they will pull to 6k with a stock LR intake

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91 B4C 305 TPI - SOON TO BE 383
TREMEC 5-SP, STOCK 1-BOLT REAREAND w/342 GEARS, K&N, AIRFOIL
EDELBROCK HEADERS, DUAL CAT TO HOMEMADE Y-PIPE & 3.5" SINGLE PIPE W/ FLOWMASTER, CRANK PULLEY, MSD, FUEL PRESS REG, COWL HOOD, WELD WHEELS
14.1@ 98MPH
-------------
OTHER RIDE
67 CAMARO - STREET CAR, BIG BLOCK, PUMP GAS
350TH w/ATI 10", 12-BOLT w/373 GEARS
10.94@124.13 ON MOTOR - ET-STREETs w/MUFFLERS

 

The 5.0's don't have a bad problem but the 5.8's are dead above 5400. I mean DEAD, even with the GT-40 intake. Plus they have the fuel distribution problems of running lean near the end of the fuel rails.

James

 

the ford intake setup is weird being a small stroke 3.00 and a small rod it revs very high very easily but the long runner design helps build a little low end tourqe that it needs the only problem is starvation even with a good intake above 6000,caams usually dont help the situation

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87 trans am 350 L98 aluminum heads,LT4 hot cam,slp runners,headers,y-pipe,edelbrock base,hi flo cat,air foil,ported plenum,t-5 tranny w/centerforce clutch and a 3.27 9bolt,ads strip chip,relocated iat sensor,hollowed maf

14.10@97mph w/2.01 60' 4SALE anyone want her?

 

How long is the F*rd intake runner? Their intakes sure seem to support a lot more HP than our TPI intakes do, yet there are a lot more aftermarket intakes for 5.0's than L98's.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

add to that the price of there stuff...you can get a complete intake for 500$, where we have to spend 600$ for something OK, where you have to drop 1000$ + for a good intake....but life is such, and somehow, we still manage to win...hehe ;-)

 

being the diverse kind of guy I am, I have both systems in stock form setting on a shelf in the shop so I can answer this. (or at least provide information so you can draw your own conclusion.)

All lengths measured using a tape measure along the shortest distance streched through the port.
All widths measured at the widest point.

Empirical data first.
<hr>
First Henrys setup:
•runner & plenum assembly;
All 8 are the same length, diameter and shape.
port length = 7 1/2".
port cross section = 1 3/16" x 1 9/16" oval shape.

•manifold base;
All 8 are different lengths, & shapes, some short & straight, some doglegged and longer. Entry is oval, outlet is rectangular
port length, shortest = 5.0" longest = 5 5/16"
port cross section at entry = 1 3/16" x 1 9/16" oval.
port cross section at outlet = 7/8" x 1 11/16" rectangle.

•total port length of all parts = 12 1/2" shortest, 12 13/16" longest.
<hr>


<hr>
Now the Generals:
•Plenum wall thickness = 5/16"

•runners;
All are same length, diameter & shape.
length = 7 1/8".
cross section = 1 17/32" round.

•manifold base;
All ports are same length & shape. Entry is round, outlet is rectagular.
length = 6 1/16".
cross section inlet = 1 17/32" round
cross section outlet = 1 1/8" x 1 3/4"

•total length of all parts = 13 1/2"
<hr>


So the GM piece in stock form has ports around 1 inch or less longer than the stock Ford piece.

The port cross section of the GM piece is larger than that of the Ford unit though.
The cross sectional area of the manifold base outlet of the GM piece is 1.97 in².
The area of the manifold base outlet of the Ford piece is 1.48 in².
<hr>

Now my opinion.
I think the two intakes are somewhat compairable. While the Ford unit is 1 inch shorter than the GM, the GM has more cross sectional area. The GM offering has more total port volume so it should flow well at higher RPM. Even though it is a little longer it should have the volume to feed RPMs. More port cross section makes for better cylinder filling at higher RPM at the expense of a loss of lower RPM filling.
The Ford piece is a little shorter but also has smaller cross section and less overall port volume. The shorter length should help higher RPMs but the small cross section should help lower RPM cylinder filling at the expense of some top end.

I don't think that either setup has clear benifits over the other.
I also would like to point out that The GM 5.0 made simular (almost identical actually) Horsepower & torque as the Ford 5.0. The interesting thing is that the GM 5.0s power peaks were at a higher RPM than Henrys 5.0 indicating simply that the GM made its power at a higher RPM even though it has a longer stroke and and longer intake runners. I attribute this to the larger port volume & cross section of the GM intake manifold and heads.

As far as the original question of the thread, I have worked extensively with both systems and neither system works very well in stock form over 5500 RPM Both will spin faster especially if other aftermarket parts like cams & exhaust are used but until the intake systems are address neither pulls optimally at the top end.
I once built a 310 CI TPI engine with stock length runners but lots of other mods that would spin 7200 RPM. It was much quicker if you shifted at less than 5800 RPM though. It was just a waste of time & energy to spin it any faster even though it could do it because it was well past its power peak by that time.

As I've said before, "if you want to beat those pesky Stangs the easiest way is to lose some of that extra weight on that F body. That is the biggest single reason that the Stangs accelerate quicker and rev through the RPMs easier



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Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

EFI Performance Club on Yahoo

[This message has been edited by IROCKZ4me (edited June 14, 2001).]

 

OK, let's keep things in perspective here:

In all those car magazines, the 'stangs run only a few tenths faster than the Irocs.
While that might look nice on paper, it's different in reality. Remember, these are *professional* drivers getting every inch of performance out of the 5-speed f*rds.
In contrast, in the real world, most of what I've seen at the stoplights is some idiot with his hat on crooked and drool streaming down his chin as he's blasting his rap music. These guys dont shift like the pros do. Sure some of them know how to, and when you find them, THEN it's a good race. I've never had any problems with a stock, or lightly modified 5.0 'stang with my Iroc, lightly modified as well. And it's not in perfect mechanical shape.
If you've got a manual car, you're on even ground. If you've got an automatic, then all you have to do is stand on it, and you should take him provided you have a 350 or a lightly worked 305

And as far as airflow goes, both intake systems are designed to build low end torque for drivability and fuel economy. Both are EXCELLENT systems, and the only possible advantage of the f*rd EFI is that it was designed around the 302, while the TPI was designed around the 305.

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1980 Camaro, '88 Police 350 engine, Headers, full exhaust, completely redone, my baby!
1988 Iroc-Z L98, MSD 6a, Accel coil, K+N's, Airfoil, Coolant Bypass, Flowmaster, Gears, Late model Bose, I like the 80 better

[This message has been edited by Steve R (edited June 16, 2001).]