yay! Got my car back together!

[Aurora40]

Got the IH's and plenum on, new injectors, and tossed in the new prom. Filled it up with coolant, and fired it up! It cranked long but then fired right up and idled great.

The slight pulsation at idle didn't go away, but it is really quite mild. I did try to balance a nickel but couldn't get it to stand up. Maybe I need to find a nickel with a less rounded off edge.

The only problems I had were that my MAP bracket got bent and one of the connectors under the plenum got chipped shipping it out. Then putting the car together, one of the PCV metal hoses had that bracket that gets bolted onto the plenum snap. It's still in place fine, but I ordered a new one.

I drove the car lightly up and down the street because it was misting out. It felt fine, but I can't wait for a nice day to open it up!

I replaced the PCV valve cover/top piece, and man does that make a difference. The old one would slide right off the valves with barely any effort. This one grips like mad and was actually pretty hard to install.

[Aurora40]

Took it for a spin tonight. It feels stronger for sure. I didn't get to do much flooring it in 1st/2nd, though. But in 1st it would break loose even at 40+mph easily. It used to just scramble and shift side to side at those speeds, now it flat out spins them with the tach shooting up. I need new tires...

That sort of mechanical sucking sound when you get on it is more pronouced. Very much an intake sound when you floor it.

Also, flooring it in 5th at like 60mph feels stronger. Of course it hardly pins you back or anything. But it feels more useable, the car accelerates like if you floored it in a V6 sedan that downshifted. It accelerates quick enough that the speedo jumps digits 2 at a time, and as you get to about 75-80mph the acceleration just gets stronger.

I would believe it made a ~10% increase in power for sure. It's not like some different animal now, but it definitely feels stronger. It always makes me wonder if ~400hp isn't all you need on the street. The car is quietish with the stock exhaust, it pulls like mad, you can break tires loose easy, what more do you need? I almost think some short-tube headers, cats, and a '93+ exhaust would be the way to go for some extra power but not too loud. WHo knows, though, I'll have to check out all the systems folks have at BG and maybe Carlisle to really hear them in person.

I did notice my car didn't idle below 800rpm now. Perhaps that's a function of the chip. I'll see what Mark says about this. It used to idle closer to 650 rpm or so once warmed up.

[tomtom72]

Holy smoke!!! That sure sounds sweet to me but then what do I know.
Bob!! Also nice to know about the top holder/connector for the PCV's. Guess I should hunt one up so I can loose my Zip Tie, mine slips on & off with no resistance at all. It's proly leaking like stink around the edges!

Let me ask? Ported injector housings + ported plenum + port matching I/H's to plenum + a chip to use with the port job + what else I don't know to ask for from a vendor. Sorry for my ignorance, I'm just trying to not be totally ignorant if I make some calls to vendors that do this kind of stuff.

I had a thought the other day...the later I/H's are different from the 90-92 I/H's. Are the 405 hp I/H's transplantable to an early motor? The later ones are said to flow better than the early ones.

Sorry for being so nosey, Bob! Thanks for any light thrown my way!

Tom

[Aurora40]

Hey Tom, you could buy the later injector housings. You'd probably need new primary injectors, though, unless yours can still have the o-ring on the end.

However, the 1990-style is ultimately better. Since the o-ring is up at the top in the IH instead of on the end of the injector, if you port it, the entire injector bump-in can be removed. Some little bit needs to be left on 93+ ones for the o-ring to seal against.

I don't know if the 1993+ heads have bigger ports. If so, the newer style injector housings wouldn't be port-matched to your 1990 heads. I think it definitely wouldn't match the plenum. All in all, for ~$300-400 for the housings, it might be better to just have yours ported. The later style plenum is not cheap, they are like $1800 or something.

But I think stock for stock, the 1993+ IH's and plenum would be an upgrade on the 1990 motor. Whether the money makes sense is another matter.

I got the IH's ported, they still match the heads, though. The plenum ported, the TB bored to 63mm secondary butterflies, and the TB extension ported to match and to reduce those bump-ins from the reliefs to fit over the P/S and AC pulleys. And it came with a chip and the gaskets necessary. All the porting was beautiful to look at, the ports are really pushing it as far as being about to join together. And the TB butterflies are absolutely huge. The only part that isn't so pretty is the TB extension. I guess as you cut away there isn't much left. The mounting surfaces for the screws are skeletonized, the screws look like they only make contact for about 3/4 of the surface. And that V'd in area for the top center mounting screw is sort of ugly and jagged ground away. I mean, it looks like nothing was spared in opening it up as much as possible, but in retrospect it's the only part of the intake you can really see, and it's pretty ugly to look at. If I had it to do again, or if the extension wasn't $400, I might have it less hogged out.

One thing I noticed today, is the car seems more tractable at lower rpms. It feels less luggy and slow when giving it gas in 5th or even 6th to pass. I don't feel a need to downshift at all, unless you really want to smoke someone. This may just be due to the new injectors, or maybe due to the porting. It's not like the car is a beast in 5th or 6th at 60mph, but it feels more useable now.

[Z Factor]

Originally Posted by Aurora40

I would believe it made a ~10% increase in power for sure. It's not like some different animal now, but it definitely feels stronger. It always makes me wonder if ~400hp isn't all you need on the street. The car is quietish with the stock exhaust, it pulls like mad, you can break tires loose easy, what more do you need? I almost think some short-tube headers, cats, and a '93+ exhaust would be the way to go for some extra power but not too loud. WHo knows, though, I'll have to check out all the systems folks have at BG and maybe Carlisle to really hear them in person.

Now that you have it breathing in better, wait until you have it breathing out as well.

Originally Posted by Aurora40

The only part that isn't so pretty is the TB extension. I guess as you cut away there isn't much left. The mounting surfaces for the screws are skeletonized, the screws look like they only make contact for about 3/4 of the surface. And that V'd in area for the top center mounting screw is sort of ugly and jagged ground away. I mean, it looks like nothing was spared in opening it up as much as possible, but in retrospect it's the only part of the intake you can really see, and it's pretty ugly to look at. If I had it to do again, or if the extension wasn't $400, I might have it less hogged out.

You would not happen to have a pictures of it would you?

[tomtom72]

Big thank you, Bob, for being patient with my Q's. I would say this about your 6th & 5th observations...I still need to downshift in 6th if I want to pass right away so I would say that all your work must have given the results you observe. Mine runs great with the new injectors but in 6th if I want to pass now I must go to 5th. So I would say a marked improvement with your set up is evident.

I was just trying to figure a way to do what you did & not need a place to lay the car up while waiting for parts to come back from a vendor. I can dream...guess I'll have to ask my uncle if I can take over the garage again later in the year so his Mercedes don't sit out in the snow.

Thanks again for explaining to me about the process and the late lt5 parts.


Tom

[Aurora40]

Originally Posted by tomtom72

Big thank you, Bob, for being patient with my Q's. I would say this about your 6th & 5th observations...I still need to downshift in 6th if I want to pass right away so I would say that all your work must have given the results you observe. Mine runs great with the new injectors but in 6th if I want to pass now I must go to 5th. So I would say a marked improvement with your set up is evident.

Well, maybe I should clarify. Acceleration in 6th won't wow anyone. But the car will accelerate at a rate you can notice. In fact, the speedo was even jumping 2 mph increments by about 70mph in 6th.

But I mean passing like on a multi-lane road. Not like pull-out-to-pass on a two-lane road. No way I'd keep it in 6th for that, probably not 5th either, though 5th might be acceptable if you had some space.

[tomtom72]

I understood exactly what you were saying, non-ported = almost non-existant 6th accleration. Now you can actually feel the improvement in 6th. Ya gotta like them results & the part about 1st & 2nd really got me to sit up & take notice. All in all I see you are impressed & that says that this stuff does work if done correctly and with the limitations in mind that the heads were not done & no headers & exhaust work. I say good luck with the new hp & have fun!

tom

Passing..... drop it down to 3rd.

[Aurora40]

Originally Posted by Z Factor

You would not happen to have a pictures of it would you?

No, I guess I could pull the duct off and snap one. It's not ugly when you pop the hood, but it's the only part someone could concievably see easily if they pulled the duct off.

It's not really that bad, it's just that it's quite obviously modified.