Q45Tech, read this. Help Me

[AZhitman]

It's allowed, even embraced.

Dennis doesn't let his out to play very often, but when he does, it's riotous!

[PoorManQ45]

The 1990 Q engine produces more torque per cubic inch [with proper fuel/ignition JWT ecu] than the 2005 Corvette engine much much more than the Chrysler 300c so called Hemi...........274 ci is a small V8.

Compare the exterior dimensions of the VH45DE to the exterior dimensions of the 350 once. Even though the 350 displaces 76 more Cubic Inches, it is actually smaller than the VH45DE. You made the common mistake of only refering to the cylinder displacement when computing the torque per Cubic Inch.

The interferrence of the valve and piston [already have flycuts in piston] means no more lift can be used without new pistons. And 0.490 with a 1.5" diameter valve is already ultra high lift and is perfection for valve curtain area vs valve seat 5 angle cuts.

Cams won't help much because the runners and plenum is tuned to 4,000, 4600, 5600, and 6,000 rpm. Figure out a way to shorten the runners by 2-3" and increase their opening diameter [area] by 8-10% [and maintain the taper ratio] and you might retune the engine to a 6800 rpm HP peak and yield aroud 350-360 HP unfortunately you would lose so much torque at 55 mph cruise that you would have to bump the diff gear up by 25%..........to let the heavy Q cruise with AC on.

Didn't you say in another forum that the VH45DE doesn't have enough valve duration at Higher RPMs? There isn't enough time for the air to fill the cylinder.

You sure are a long way from saving a few bucks with garden hose plenums to spending $10,000 modifying an engine.

Like I said before, I'm just thinking out loud. I just ask these questions to get information. Who knows, when I get a job, I might actually do some of the things that I'm asking about. And then, your information will be very valuable when I try to save more money:).

Important to take your medicine everyday as Lithium can do that to you. " NO HIGHS, NO LOWS", skip a pill and cams come to mind - seen it often on the boards.

Wow Q45Tech made a funny.

[squeefoo]

Compare the exterior dimensions of the VH45DE to the exterior dimensions of the 350 once. Even though the 350 displaces 76 more Cubic Inches, it is actually smaller than the VH45DE. You made the common mistake of only refering to the cylinder displacement when computing the torque per Cubic Inch.

I really shouldn't ask: After hoping that wasn't a complete thought, I need to find out what the voices say is the proper way to compute torque?

[maxnix]

I really shouldn't ask: After hoping that wasn't a complete thought, I need to find out what the voices say is the proper way to compute torque?

OK, you get the Captain Obvious award.

Boy, talk about some real free-thinking.

[pito11213]

Sarcasm is certainly about all of the forums today.

[Makanly]

I really shouldn't ask: After hoping that wasn't a complete thought, I need to find out what the voices say is the proper way to compute torque?

This is PMQ.

Why's that.

Seriously, compare the exterior dimensions of the 2 engines. Take the outside volume and use that to compare the HP and Torque of the two engines.

Compared to the VH45DE, the 350 is very small. This is because the 350 is a pushrod engine. There is only one cam, and that is housed between the cylinder banks(which go unused on a OHC engine) This allows the wholes engine, mainly the heads, to be smaller.

[DAEDALUS]

We're talking about engine efficiencies here. If you read car magazines you will *routinely* see the term HP/liter. I have never read a comparison of HP/envelope volume. To say that making a HP/l comparison is a common mistake is only half true. It's common; it's not a mistake.What are the dimensions of a 350 longblock?

[Q45tech]

A cams duration is correct at only one narrow range of rpm [why we have modern designs with VVT or VTEC or iVVT] to try to fake a duration change.

Obviously a higher lift acts like more duration to a point where the air flow keeps increasing.

VVT in Q just shifts the FULL closing time of the intake valve 20 degrees later [instead of 48 degrees after the piston starts moving up it occur at 68 degrees after the piston starts moving up from the bottom.

This acts like the cam suddenly increased duration from 248 to 268 with is optimum for 6,000 rpm. Just as 248 is optimum for 4,000 rpm with valve diameter and lift and 3.66" bore size.

The exhaust cam closes fully at 8 degrees after the piston is at the top on the exhaust stroke but REALLY stops flowing when the piston is at the top.......nothing more to squeeze out except what's in the head space.......1/10th of the entire volume. At under 4600 rpm the intake being open 20 degrees before TDC helps wash [flush] some of this 10% residual burned gases OUT [28 degrees of overlap]. This works best at 4,000 rpm.This washing out action is traded for more air filling from the intake above 4600 rpm when the intake opens later [VVT moves the intake cam 20 degrees later.

The point is the motor needs more exhaust duration above 4600 rpm and really more above 6,000 rpms. Why loud less restrictive exhaust help increase power above 4600 rpm and really above 6,000 rpm.

We have a total of 10% [residual gasses] mixing with and inhibiting the inflow of fresh air into the cylinder after 4600 rpm.

A valve doesn't flow much till 10% of peak lift occurs and shuts down as 90% closed and there is slop in the mechanical translation of cam profile to lifter to valve mechanical action so really a 248 degree cam is more like a 180 degree valve action [what you would expect].

The following is a good example of valve flow vs valve lift.......see not much increase above 0.400" lift.http://e30m3performance.com/te...1.htmSpecial case:http://e30m3performance.com/te...4.htm

[PoorManQ45]

A cams duration is correct at only one narrow range of rpm [why we have modern designs with VVT or VTEC or iVVT] to try to fake a duration change.

Isn't the listed duration the maximum time/degrees that the valve will be open?

VVT in Q just shifts the FULL closing time of the intake valve 20 degrees later [instead of 48 degrees after the piston starts moving up it occur at 68 degrees after the piston starts moving up from the bottom.

Um... Keeping the Intake valves open while the piston is traveling up the cylinder would seem kind of dumb. Wouldn't that force air out of the open valve?

The exhaust cam closes fully at 8 degrees after the piston is at the top on the exhaust stroke but REALLY stops flowing when the piston is at the top.......nothing more to squeeze out except what's in the head space.......1/10th of the entire volume.

Does that mean that there is 8 degrees of overlap between the intake and exhaust? Wouldn't that cause exhaust gases to re-enter the cylinder? If so, is that to better fill the cylinder?

At under 4600 rpm the intake being open 20 degrees before TDC helps wash [flush] some of this 10% residual burned gases OUT [28 degrees of overlap]. This works best at 4,000 rpm.This washing out action is traded for more air filling from the intake above 4600 rpm when the intake opens later [VVT moves the intake cam 20 degrees later.

What good would it do to force exhaust gases out of the intake valves?

[DAEDALUS]

Isn't the listed duration the maximum time/degrees that the valve will be open?

For a given lobe there is only 1 duration of open interval, no max, no min. VTEC has 2 lobes per cylinder/camshaft to give an entirely different profile, whereas VVT uses the same profile but shifts the angle of it relative to the piston location.

Quote »Um... Keeping the Intake valves open while the piston is traveling up the cylinder would seem kind of dumb. Wouldn't that force air out of the open valve?[/quote]I've got different angle values in my manual, but yes, the intake valve is still open when the piston begins its ascent. In a very slow moving engine yes, this would force air out, but think of the air like a freight train. It has mass and it has velocity. As the piston changes direction at BDC, the air at the top of the cylinder is still pouring in and continues to do so for a finite period before air is forced backward out the cylinder. Leaving the valve open just a bit takes advantage of this to improve volumetric efficiency.

Quote »Does that mean that there is 8 degrees of overlap between the intake and exhaust? Wouldn't that cause exhaust gases to re-enter the cylinder? If so, is that to better fill the cylinder?[/quote]8 degrees overlap between intake opening and exhaust closing. Reasons are the same. The exhaust gasses have momentum and are on the way out. 8* of angle is the same time period at any point of rotation for a given RPM, but at either TDC or BDC 8* is barely any linear movement of the piston. When you force a piston down a cylinder the pressure movement is not instantaneous, just as the breeze from a fan that was just turned on isn't felt across the room right away.

[texasoil]

I like your attitude about finding low cost parts--where can I get some. I want to look at them and judge quality myself.

The lowest cost brake rotors I know are for MBZ cars--and they are very predictable. Q45 rotors from O'reily's are <50% of dealer--but the parts guys are always surprised at how pricey they are compared to other makes.

Re:under plenum stuff--for the frequency needed, and the effort to get to them, 99+% are far better off with OEM. IF you can do a good kit for $50--I want 2 right now.

[PoorManQ45]

I like your attitude about finding low cost parts--where can I get some. I want to look at them and judge quality myself.

I get most of stuff at Autozone, Advanced Discount Autoparts, or Napa(=$$$).

The lowest cost brake rotors I know are for MBZ cars--and they are very predictable. Q45 rotors from O'reily's are <50% of dealer--but the parts guys are always surprised at how pricey they are compared to other makes.

There is no real reason that one brake rotor should cost more or less than another. If there is no major difference, ie.. titanium alloy vs. steal. Of course the titanium alloy discs are going to cost more.

Some people think that because of the weight of the vehicle(4200lbs+), that the discs should be beefier. This is not true.

I have a friend that has a caprice classic(4500lbs+) and his rotors were approximately the same thickness as those from the Q. His cost $7 each from Autozone($24 from chevy), mine were supposed to cost $22 from Autozone($50+ from infiniti).

When I heard $22 for a rotor, I thought "There is no way in hell that I'm going to pay $22 for a brake rotor." So, I had the guy at the counter cross reference the infiniti discs with other nissan discs, by part number. He didn't find any in the computer. I asked him to actually check the other rotors from nissan that he had in stock. He found a rotor that looked the same, had the same measurements(used a caliper), and weighed the same(used a scale), but were $15 less.

So, what was/is the difference between the Infiniti Q45 rotors and the ones that I got? Price, that's it.

And guess what. My rotors have a Lifetime warranty. Do your Infiniti rotors have a lifetime warranty?

Also, my brake pads have a Lifetime warranty. They will replace them for free. So, I replace all my brake pads every 6~12 months, for free. I replace my rotors every 1.5~2 years.

Sometimes I replace the brake components even if they are in good condition. I like the idea that I am actually saving money by replacing the brakes.

[AZhitman]

You were comparing cheap Chinese rotors to cheap Chinese rotors. You neglected to compare them to an OEM quality/weight rotor.

I'm assuming you're a metallurgist, so i won't get into the materials issue.

I know you desperately want someone to tell you you're right, but your bargain pads and rotors will cost you six feet in stopping distance (not to mention the additional six feet of stopping distance added by your cheap hard-compound tires).

That adds up to you punching a Q45-shaped hole twelve feet through someone's car that ran a red light.

You can hand over your $15 savings to the grieving family.

[AZhitman]

Some people think that because of the weight of the vehicle(4200lbs+), that the discs should be beefier. This is not true.

I have a friend that has a caprice classic(4500lbs+) and his rotors were approximately the same thickness as those from the Q.

WAIT! Everyone stop what you're doing!!!! Let's all go buy some Hyundai Excel rotors, because SOME GUY with a Caprice has Q-sized rotors!!!

Dude, you're treading again.

A Crap-pice Classic doesn't have 278 hp either.

Stop while you're ahead.

Remember, less posting, more reading.

[Jesda]

I've driven the last generation Caprice extensively. I lived with a friend whose folks owned one, this was a 96 with 100k. Took it to prom even. Talk about roomy!

Anyway, the brakes suck... badly... even with OEM Chevrolet parts. I would not use the stock 200hp overweight Caprice as a performance benchmark for anything. I loved driving it and it rode like a creampuff, but by no means should it ever be mentioned in the context of performance. Its biggest safety feature is that anything that it hits will be like driving over a squirrel. Take your living room, put it on four wheels, and make it move. Wallah! Instant Caprice!

The Impala SS on the other hand is another beast.

-Jesda

[szh]

WAIT! Everyone stop what you're doing!!!! Let's all go buy some Hyundai Excel rotors, because SOME GUY with a Caprice has Q-sized rotors!!!

[PoorManQ45]

You were comparing cheap Chinese rotors to cheap Chinese rotors. You neglected to compare them to an OEM quality/weight rotor.

I thought I explained that OEM rotors and the ones that I have are the same thing. They're probably made in different places. Mine are made in china(nothing wrong with that), your's are probably made in Japan or the USA

I'm assuming you're a metallurgist, so i won't get into the materials issue.

You'd be right in that assumption.

I know you desperately want someone to tell you you're right, but your bargain pads and rotors will cost you six feet in stopping distance

If you didn't notice, I didn't cheap out, too much, on the pads. $75 for carbon-ceramic compound brake pads. They produce almost no brake dust, no noticeable noise, and the stopping distance seems just fine.

(not to mention the additional six feet of stopping distance added by your cheap hard-compound tires).

I do not cheap out on tires either. They are the only place that you car contacts the ground. I use Grand Spirit AquaFlow 225/50ZR16 their load rating is 1389lbs. They cost me ~$90 a piece. They're really great when the road is wet. Their dry traction is pretty good. They are a medium-compound tire.

That adds up to you punching a Q45-shaped hole twelve feet through someone's car that ran a red light.

4200lb car vs. 3200lb car, 4200lb car wins. I'm not saying that I would hit anybody on purpose. And, if the other person is the one that ran the red light, I get a big *** check from the insurance company.

You can hand over your $15 savings to the grieving family.

Only $15 dollars in savings? I save $75 dollars every time that I change the brake pads. Lifetime warranty, you know. They will replace the pads when they're worn out, for free. That means that I have saved $150 on brake pads alone.

A Crap-pice Classic doesn't have 278 hp either.

You're correct. It has over 350hp. It's got a 350 police interceptor in it.

Remember, less posting, more reading.

I'm trying to help you guys out. I have personal accounts of what I'm talking about.

[PoorManQ45]

I would not use the stock 200hp overweight Caprice as a performance benchmark for anything. I loved driving it and it rode like a creampuff, but by no means should it ever be mentioned in the context of performance. Its biggest safety feature is that anything that it hits will be like driving over a squirrel. Take your living room, put it on four wheels, and make it move. Wallah! Instant Caprice!

I just used the Caprice classic as a weight benchmark.

I loved driving it and it rode like a creampuff, but by no means should it ever be mentioned in the context of performance.

I like the way the caprice rides. You can take a sbeed bump at 40mph and it just feels like you're riding a really long wave. Handling wise, it sucks big time.

Its biggest safety feature is that anything that it hits will be like driving over a squirrel. Take your living room, put it on four wheels, and make it move. Wallah! Instant Caprice!

Caprice Classic =

The Impala SS on the other hand is another beast.

Very true. But actually, they are the same car with different engines, normally. Now, a caprice classic with a police interceptor motor in it is the same as an impala ss

[maxnix]

I do not cheap out on tires either. They are the only place that you car contacts the ground. I use Grand Spirit AquaFlow 225/50ZR16 their load rating is 1389lbs.

I'm trying to help you guys out. I have personal accounts of what I'm talking about.

Don't know about the brand (Cooper?), but way under the OEM minimum load rating of 95 (1521 lbs.). Like AZhitman says, stay the hell out of my neighborhood.

I think your personal account is overdrawn, again, yet, still.......

[AZhitman]

Good God.

There's so much misinformation in this last post I can't possibly refute it. But I must.

Parts store rotors are NOT the same as OEM. Anyone can call their crap OEM-replacement, but they may be lighter, thniner or cheaper metal.

Good job on the pads. You could have had Axxis Metal masters or hawks (both proven quality) for less money (OH NO!).

Your tires do not have sufficient load rating for the car. Period. They're a hard-compound, high-mileage granny tire, and for LESS money you could have bought some good, sticky performance tires. http://www.tirerack.com/tires/...1=yes

Those tires are also a FULL 1.3" smaller than OEM diameter. It's no wonder your speedo reads wacky.

No one said you would hit anyone on purpose. You are at the mercy of your tires and brakes, and while your brakes sound like they're fine, your tires are insufficient to stop a car the size of your Q in anywhere NEAR the original stopping distance as tested when new.

BTW, You get NO check if the red-light runner's attorney can prove your car was poorly-maintained (this post being Exhibit A).

The Crap-price has 260 horsepower, not 350. You know nothing. http://www2.pcrepairnj.net:8080/caprice/about.html

I will not caution you again about posting misinformation in these forums. Some people come here to LEARN, and I don't want an impressionable person reading your inaccurate information and believing it.

[s13sr20chris]

i have a buddy with an ex-cop car caprice classic. i think its a 96. has 300 hp(or whatever) lt1. you know, the one with the dist behind the water pump yeah, hes trying to get down into the 14's. he also cant stop even with his abs. big old slug of a car. def a lot better than the standard cap class. what does the standard have? 4.3 v8 or something like that. pooPMQ, i like reading what you post. i dont agree with most of it. but i love your enthusiasm and your cheapness. has it got the best of you? yep. but its still interesting. BTW- i have assembled a vh45de with generic hose stock before. i did not want to but the owner insisted. it started out as a tune up and then moved to valve cover gaskets. next thing i know im just replacing everything. he got me some hose stock and i did it. did not run right and seemed to run a little warm(temp gauge did not budge though). idled rough though was imperceptable from inside. never saw him again. he stiffed me on about a third of the bill so i cant help but hope i see him and his car again

[s13sr20chris]

oops, i just noticed the little locky thingy on the thread title. sorry.