Originally Posted by CATransam

it looks a lot like the Harrop manifold (just without the 8 TB's)



http://www.harrop.com.au/root_folder...fd7022-00.html

Originally Posted by FieroZ34

I am completely shocked by Harrop's injector placement. Why not put the injectors at the top of the runner? Yes, it'll idle like crap. But it's going to idle like crap because they are ITBs, and if the owner dropped the money for that manifold, there's no saying how radical the heads/cam package is, so that's going to make it idle like crap anyways. And yes, the low end will not be as smooth. But I don't think that's an issue with 600 lift cams and 350cfm heads.

The farther away from the head the injectors are, the more power they'll make. That's why F1 puts them in the damn airbox. That being said, that thing looks SICK.

Originally Posted by FieroZ34

Hehe, I'm starting to wonder the same thing. Basically, weight. About 2800lbs with every option, and an all-iron V6. Not to mention traction, I cut consistent 1.6 60's with just 240hp

Originally Posted by Beast96Z

I don't agree. I own one of these intakes, and the injectors are placed at the same location of the stock intake. The injector mist is so fine, I don't see were it would matter. As for idle, a ITB intake will idle 100,000 times better than a single TB intake. You can have the nastiest of cams with this intake and let your granny drive it to the grocery store. Individual runners gives each cylinder it's own atmosphere, thus all but eliminating cross cylinder contamination and vastly improving driveability. Top-end or low- end, it's all better. F1 cars are completly diffrent from LSX motors, so I see no comparison. If you tried to put 8 injectors in a LS1 air box, I guaruntee you, you'd be lucky if the car cranked. In australia, where these intakes are made, 240* duration cams and 106 LSA's are normal in 346's with these intakes. Idles smooth and drives great.

Originally Posted by FieroZ34

I never said the ITB will idle like crap solely because it's an ITB. I said it' idle like crap because we can assume the operator also has trick heads/cams. And while your's may be smooth, there's no way in hell it is as smooth as stock, and at the stock RPM with that cam. I just don't believe it.

Originally Posted by FieroZ34

This is how mine are, and I'm not going on a whole "It must be good becuase I have it" thing, but I did a lot of research so that when I dropped $1500 for my ITB intake, it was the best that it could be.

Originally Posted by FieroZ34

It's been shown time and time again, the farther away they are, the more power they'll make. But on a street car, the effects are sometimes worse than the gains, depending on the owner.

I never said the ITB will idle like crap solely because it's an ITB. I said it' idle like crap because we can assume the operator also has trick heads/cams. And while your's may be smooth, there's no way in hell it is as smooth as stock, and at the stock RPM with that cam. I just don't believe it. Also, if the injector is placed before the throttle plate, your idle and low RPM response is going to totally suck. In this case even a stock head/cam LS1 won't idle below 1500rpm.

I was exagerrating when I said put them in the airbox. You'd obviously have to direct them into the runner, but the injector is still above even the velocity stack. This is not optimal in a street car, as we can't idle at 7000rpm. Thus IMHO the best location is right after the plate, but still as far up the tract as possible. This is how mine are, and I'm not going on a whole "It must be good becuase I have it" thing, but I did a lot of research so that when I dropped $1500 for my ITB intake, it was the best that it could be.

I wish my Fiero ran low 10s.

Originally Posted by MrDude_1

if by "alike" you mean they both have 8 runners... yes.

otherwise... uhh.... huh?

Originally Posted by racer7088

The independent runner stuff with the small independent throttles before each port with the constantly pressurized near 100 kpa "mega plenum of the world" above those same little throttle bodies are just less affected by the exhaust reversion that affects a plenum car worse since the whole intake system on these setups is at very low pressure and the exhaust is at such a higher pressure. The exhaust reversion can and does fill up the whole plenum behind the central TB or carb and the whole runner of each cylinder with exhaust diluted air that causes the repeated and erratic misfiring that we hear as the cool loping sound some people love so much.

With enough overlap the IR systems will also lope too and turn black under those cute little throttle bodies from idling with all the same vacuum under them when they are closed and idling but they have less of the total runner to become as contaminated since the higher pressure is close at hand right above them and in the rest of the runner. You will sometimes, with really big cams in these systems see the exhaust and regular reversion in the form of standoff above the runners with some of them at lower engine speeds.

Also when you crack the throttle instead of an entire manifold plenum having to pressurize up slowly instead, now the port sees full atmosheric pressure and density basically almost instantaneously so the throttle response is WAY better. In fact some people need a progressive linkage or it's too jerky for them! Also just realize that Australians ARE crazy and they all drive cars with blowers and NOS and have mohawks. They also like cubic inches in a lot of their racing and RWD but that's finally coming back to the USA too as people here have had their fill of the FWD crap.

Originally Posted by cary et performance

there are various different port combinations. One does not fit all. That particular one is for a 400 inch 2200-2400hp blower combo.

Originally Posted by billybob77036

On that Harrop C5r, how large are the tb's? I know they offer them on the normal intake in the 54 and 58mm size (IIRC), did they enlarge them any for this version? With the new LSx blocks coming out that will allow 500"+ I can't wait to see the intake market play catch up with itb setups.

Originally Posted by J-Rod

FieroZ34 you comments on the Harrop intake are incorrect.

The intake actually improves idle quality far over that of a shared plenum intake. I know folks who have built ITB setups with the injectors up top, and down low. There are benfits and drawbacks to each.

I can show you videos of cars both on the dyno and in car of ITB setups, and eren with what we'd consider a MONSTER cam here in the states it idles like stock.

You have to understand some basics about how an ITB works. This has been covered in other threads. This post sums it up...

Originally Posted by JL ws-6

damn... that open injector setup is nutty LOL. I wonder how bad that engine bay stinks like fuel LOL.

I'd love to put one of those on my car.. btu with zero way of filtering the incoming air I dont' think it would be a really good idea for any street use at all. But it sure would catch some attenion at a carshow.. imagine walking by a 4th gen transam and seeign that under the hood.. you couldn't get people away from the car with a fire hose.