HO TB swap

[91GMLS]

im wanting to buy a HO tb converted to a lopo engine give me prices it have to bolt right up. about how much horsepower will i gain from this mod. i also have a 2000 crown vic intake mounted up. i can tell a big difference in performance

[BerniniCaCO3]

iirc it's not much work; I had to add a bracket to the egr, and on the TB, drill out the retaining pin (it's peened over), and drill and tap for a 4-40 screw to hold the mirror-imaged lopo piece on.
I can go into greater detail.
Easiest/cleanest is to have a local machinist bore out the lopo egr spacer. I was quoted $80 in Baltimore.

[BerniniCaCO3]

I forgot to say.
The HO throttle body gives more performance, by having a larger surface area/ larger diameter, for more airflow.
I do not know what diameter a stock crown vic intake manifold from 2000 has, but it would be best if it were the same diameter as the HO throttle body, and of course, the HO egr spacer or lopo bored over to match the HO.

But furthermore, the engine computer uses the throttle position sensor, which only can tell how many degrees the throttle plate is cracked open, to deduce how much air is making it in to the intake.
If you put in a larger throttle plate, you're letting in more air for for the same #degrees. The engine's computer won't know you've done this, so it'll still assume lopo diameter... and you'll end up running lean all the time.

I don't mean to patronize, possibly you have thought this through. But if not, then make sure to consider everything that needs to change.

I myself did a mostly straight up HO swap. HO camshaft, HO injectors, HO intake and throttle body, and, of course, HO computer to run everything as it knew best.

If you've still got a lopo camshaft and lopo computer... I dunno. I know, there is some way that guys can reflash/reprogram/retune one of these old computers, to feed it new values for the larger throttle plate. After all, mustang guys put on even bigger throttle bodies than stock HO all the time, so there's some way they're getting their stock computers to compensate. Or maybe you can put in a lying throttle position sensor... though I don't think that would work. I'm out of my territory there. Never done any custom tunes.

[turbo2256b]

You can bore the LOPO EGR spacer and bolt the HO TB and spacer to LOPO intake. Aactually thats exactly how the first few years of the Mustang did it untill the HO upper was introduced. Yws the TB needs to have the belcrank rotated 180*. Some I have just drilled the linkage holes 180 in the plate. If you are not up to boring out the EGR spacer it can be ground out a bit to clear the throttle blade. I have done it all of the ways described with the LOPO ECM. It worked fine. But what other mods have you done may depend on if it will be too much for the ECM?

[zoomie]

im working on boring out egr spacers i just need to get ahold of one and go from there if so il be ablet to bore them out for the gmn !

[BerniniCaCO3]

when I mail back my converter core, I can send you my old lopo egr spacer! I was just going to chuck it! So long as it fits in the same box, no problem.

[zoomie]

when I mail back my converter core, I can send you my old lopo egr spacer! I was just going to chuck it! So long as it fits in the same box, no problem.

Awsome!

[85crownHPP]

I must know more about this 2000 model Vic intake you put on your 91 GMQ

[87gtVIC]

I would think he means air intake.

[85crownHPP]

aahhh that would make more sense. I always think 'manifold' when I see 'intake'

[1990LTD]

I must know more about this 2000 model Vic intake you put on your 91 GMQ

I had to read it several times to figure that one out.

[91GMLS]

my bad i have a habit of doing that. it is an air intake. and thanks to all who replied i found one that been converted for me for 20 bucks

[pantera77]

Putting an HO TB on the stock lopo upper intake will gain you nothing. Putting an HO TB on an HO upper intake and 63mm bored out stock EGR spacer will net you some nice throttle response and is a good base for future mods.

In fact I'll still argue that the HO TB/upper intake/EGR spacer is the best bang for the buck on these cars.

[turbo2256b]

It gains some as the original HO Mustangs came with the LOPO upper and 60+ mm EGR spacer. It will work also just champhering the orig panther EGR spacer to clear the throttle blade. I have done it both ways. The ported LOPO upper will out perform the HO upper at least on our heavy cars. Possibly do better on a Mustang to a point. One issue even with E7 heads if you cant turn over 5800 power with either intake poops out before 4800 good valve springs 5800 or so no real benifit. I have tested about every combo carbed or SEFI. I did jump from ported HO upper and lower to a Victor 5.0 so did miss out on the Performer and RPM EFI stuff. Did it with ported and non ported heads. I am not going to tell you about something I havent tried and run for thousands of miles noting performance, fuel economy, driveability and how to install the stuff.

[jayh]

it would make alot more sense to do an explorer tb IMHO