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You like my bulge.

In the ET street R and S/S, the only two options are a 275 (26.1 OD) and a 305 (28" OD).

There is no current 295 size that I see on MT's website. The 305 is obviously a better choice in cross section and OD, but I didnt want to fuck around with rolling fenders as I'd like to DD these for a bit.

But... the coilovers seem to be doing a great job and I have room for adjustment, so I'll probably go 305 next time around.
I was just talking with a buddy about the tire size best to use. Neither he or I are interested in rolling fenders, ect. So 305s are out. I can't see the ET street R and S/S in 275 flavor being a bad idea for cars not competing. The M&H 275/50/17 gets solid reviews as well.

Also, 830 on pump......god damn. That's hot. You're probably 900WPH on E/70.

Glad you got your bitch back.
 
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Been busy so have not been paying much attention to forums lately.

Jesse wrote:
"830 RWHP, 740 RWTQ on 93 pump – with a dirty run (ie mixed KR).

EDIT: Oh, and I was like 10:1 AFR on pump gas the first run. Turns out, my wideband is accurate and the previous dyno must have been off, certainly accounting for much of the previous lack-luster results. @Rubberduck"

==========================================================

That's certainly not bad at all..lol

In fact your HP to CID ratio is very good at 2.07.

With a rear wheel torque of 740 lbs. feet and using a static
compression ratio of 10.0:1 (can't remember exactly) that
then converts to a 'Dynamic Compression Ratio' of ~18.4:1
at 'Peak Torque'.

Hence the requirements for using the correct fuel. . . .

If the engine made 830 fwHP, then it would require about 1245 cfm.
That means your cylinder heads are flowing @ 311 cfm.

-assuming you shifted at 6800 rpm-
That also means that your %VE is equal to ~158%.

Making more assumptions regarding your cylinder head porting,
I would think the velocity through the MCSA would be ~249 fps.
I am assuming an 3.0 Sq." MCSA.

If you could raise that to about 285 fps, your cylinder heads
would then be flowing ~356 cfm.

Potential fwHP would then be ~955 fwHP on ‘Gasoline’.

Your heads should not move into 'Sonic Choke' until about 285 fps.
I don't believe they will make +300 fps, on a live engine.

Maybe they will flow with a higher velocity on 'The Bench',
but I don't think they will exceed 285 fps on a live engine (JMHO)!

Now, even if they do move into 'Sonic Choke' on the live engine,
a good, a real supercharger will just move into 'Compressible Flow'
and the engine is still fed more air, as a real Supercharger compresses
or compacts the air molecules.

This increases the 'Density Ratio', or as some call it, the 'Mass Flow'.
Either term is proper when speaking about a Supercharger!

-----------------------------------------------------------------

You mentioned encountering some KR.

That is most likely what is holding your torque number down, as I would
suspect a torque number of something over 800 lbs. feet.

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Finally, 100% cylinder fill on your 401 cid engine is about 815 - 830 fwHP.
You accomplished that. . .

Most have to move to E-85 to do this.
In my opinion, doing this on pump 93 is highly commendable!

Not only have you given up Octane, but you don't have the
cooling effects of an oxygenated fuel to help cool the cylinders.

Nice Job For 'Street Iron' on 'Pump Gas' Jesse!..(y)

Cheers,
Bruce
 

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Discussion Starter #1,003 (Edited)
So just a little update: I refined the idle and timing, and then remapped the VVE tables, and I have to say the drivability is truly excellent. It drives better now than it did when I was still just heads/cam on the old motor.

The Monster LT1S has held up beautifully and no issues so far.

Adam's fuel hat is great, no leaks and no fuel pressure issues at all (even on 50% E).

Even the DR's drive pretty well on the highway for being unbalanced and... drag radials.

I got my A/C working also, so life is good! I think I just need to pull a little ethanol timing down low to reduce light throttle surging on cold start (backing up the driveway on higher E is a little touchy).. and it will be perfect! :D
 

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The Monster LT1S has held up beautifully and no issues so far.
Definitely interested in this facet of your build, as I have the same unit, and will be adding ALLLLL the boost soon. Do you also have the Monster slave cylinder? I forget, which shifter do you have, did you go with the CS short throw?

Sent from my Pixel 3 XL using Tapatalk
 

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Surging is about your idle control tables. Id ask Pat what he thinks. Ive messed with mine some myself and have got it running decent.
 

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Discussion Starter #1,006
Surging is about your idle control tables. Id ask Pat what he thinks. Ive messed with mine some myself and have got it running decent.
The idle is fine (idle timing tables are used up to about 5mph and/or clutch in, IIRC though); it's just under increased load going up the hill, it will hit different load cells and change commanded timing by like 10-15*, resulting in the bucking - it's just this one specific area on 50% E, so I just need to smooth out the timing and it should be good. But my HP Tuners is starting to act up and quit after 30 seconds of logging so I haven't messed with it since getting the car back.

Definitely interested in this facet of your build, as I have the same unit, and will be adding ALLLLL the boost soon. Do you also have the Monster slave cylinder? I forget, which shifter do you have, did you go with the CS short throw?

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I'm pretty sure I used the OEM CTSV slave - I have a link to the install in my signature that covers all that. I also have the CS short throw and have been pretty happy with it.
 

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He’s running the stock slave.

I’m in the middle of the triple disc swap myself, monster is telling me they won’t warranty the clutch if I don’t purchase their slave cylinder... slave setup is pretty damn short, I sent them all the measurements, waiting to hear back now.
 

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Jesse, why don’t you come watch the Trump fireworks at Mt. Rushmore, and show me how to fine tune my tables!? ;)
 

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Discussion Starter #1,009
Can we take pot shots at rioters from the top o' the mountain?
 

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Can we take pot shots at rioters from the top o' the mountain?
We are fortunate enough, those retards aren’t around here! Also, during softball last night, there were four new Osprey making the rounds (I’ve never seen an Osprey here in my life), along with multiple other helicopters. I think they have it locked down pretty well!

I’ll buy all the beer though! ;)
 

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Well, its 91*F so boost was off a bit - but I'm finally able to lay it down in 3rd gear!


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Jesse,
For whatever it is worth; your up against the cams limits now as related to an NA Engine.

Any further gains must come from either making the engine more efficient / tune, mass
flow recover, etc., or an Supercharger that can hold the required higher Pressure Ratio
to increase the density ratio.

There is most likely an easy 75 - 100 fwHP in a high quality E-85.
But the quality of the 15% gasoline can still cause self detonation.

Some are purchasing pure E, and then diluting it with a high quality gasoline to overcome this.

=======================================

As I mentioned in my previous post, your 830 HP states that
your operating at ~158% VE.

At 900 fwHP your VE% needs to be about 170%

Your cam is good for about 108% VE. . . NA Engine.

-based on shifting at 6800 rpm-
Your piston speed will generate an 'CFM Supply' amounting to about 1062 cfm.
Your cylinder heads will meet that 'Demand' easily.

At 900 fwHP your engine cfm demand will be about 1343 cfm. . .On Gasoline!

Your cylinder head runner volume is good for about 943 fwHP.

So some simple math concludes:
=>(170 - 158)= <12%>

=> (1343 - 1062)= <291> cfm.

If E-85 added 100 hp, then equivalently you would be adding ~150 cfm.

I am thinking that if you mix up some 100% Ethanol, with some
high quality Race Gasoline, that between the ~100 HP the E
might be good for, along with the ability to tune the engine better,
or more ideally, you'll see +900 fwHP.

If you still encounter KR, then simpy add some Toluene to the gasoline.
You might end up with E-70, but don't let that worry you with the Toluene.

Usually one does not have to add more than ~10% Toluene
to a good / high quality gasoline to see an positive effect.

Don't chase the HP at first. . . .

Watch the Torque number, as well as the Peak Torque RPM number.

If you run an Absolute Pressure Ratio of 2.2 with your engine.
it should multiply out to (2.2 * 401)= 882 lbs. feet of torque,
as your engine has about a 10.0:1 static compression ratio.

With your engine, cylinder heads and cam, an NA Engine with
about 15.0:1 static compression ratio, would make peak torque
at about 5,544 engine rpm.

Increase the cam duration to 285° and peak torque
would occur at about 6,840 rpm with an NA Engine.
** that's a bit more cam then you need, when shifting at 6,800 rpm..😄

-while i based the calculations above on your engine-
The above makes the assumption that the valve size,
port volume and MCSA are all of the proper size, in
relationship to the cylinder size. Again, everything
must 'Scale'!

Now, we must also understand that a boosted engine will make
peak torque sooner, or at a lower engine rpm.

This is because the Supercharger fills the cylinders quicker
at every engine rpm, as well as more thoroughly.

How much sooner can be calculated, but I would require
some a lot of good data to accomplish that accurately.

Finally, 900 fwHP will require about 1343 cfm.

If that were true, then the velocity through your 102mm TB
would be about 254 fps.

I like to see that number through a TB around 240 fps.

But then again; your going to move oxygen around
the TB using Ethanol.

At 830 HP, the velocity through the 102mm TB
would be about 236 fps.

I think that if you and Pat G. move slowly, so you don't
loose the rabbit, you'll succeed.

Cheers,
Bruce
 
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