SY 2373 Ramblings

[randy merritt]

Re: vortec swap

Re: vortec swap

OK, here is dyno chart from sat. RWD only. Dyno guy said that the torque converter "unlocked" at max. HP. Not doubting the guy, but I find that a little hard to believe, as it is a recently rebuilt PI Vigilante TC. I was not in the driver's seat, as it was a "dyno day" and they would not let the vehicle owners operate the vehicles, but the motor sounded like it pulled smooth all the way to 5000 rpm, which is where I told him to let it off at. TQ and HP seem to be climbing steep, but die at 4600 rpm. Any thoughts are welcome. Only thing I can come up with is more MSD woes at higher RPM's, even though I thought I fixed that with direct wiring to battery. Possible tire slippage? Tires were at about 50 psi, and they/I did not air them down.

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[Petesgn]

Re: SY 2373 Ramblings

Whats your setup ?
What was your boost on the dyno
AF during the run ?

 

[randy merritt]

Re: SY 2373 Ramblings

Whats your setup ?
What was your boost on the dyno
AF during the run ?

long story, but built short block, ported vortec's, comp 415, gt35r, 60 lb's, heavy meth, tuned by Alex. boost at 20 psi. A/F at about 10.5 at WOT. Zero knock.

 

[AWDcameoLSX]

Re: SY 2373 Ramblings

How quick is the spool of that gt35r and does it have a little more boost left? Thinking of using one on my build.

 

[randy merritt]

Re: SY 2373 Ramblings

How quick is the spool of that gt35r and does it have a little more boost left? Thinking of using one on my build.

The spool is very quick, but then agian, I've never had any other turbo on the truck. Seems like it spools as good as any modern turbocharged vehicle. I would say the turbo is all in within 2 or 3 seconds of flooring the gas from a dead stop (no boost launch). It is a ball bearing turbo, so it does spool quicker than journal bearing turbos.

After lots of research the past couple of days, I have determined that my turbo should support about 600HP max. That is more than enough capability for me. I think I will end up running about 25 or so PSI. Of course that number keeps going up as time goes on and the truck keeps running good.:tup:

 

[qbnkiller]

Re: SY 2373 Ramblings

hey Randy...those pulls were at 20#. Looking at the compressor map for your GT35R, you are at the choke line for that boost level. turn the boost up a bit and you should see 450-475rwhp around 24-26#.

As for the converter unlocking, you can lock it in with a jumper through theb ALDL. It could have unlocked if they mistakenly tapped (or activated) the brakes (microswitch behind pedal). it doesnt take much.

All in all Randy, doesnt look too bad. The other dyno chart is better-looking. I still think your cam is not helping you make power higher in the rpms. I will try to find my V6 one from last year to show you the difference. NOTE TO ALL: the COMP CAMS everyone likes to buy (412, 415, 422) are NOT designed for boosted engines. Do a custom cam and dont look back.

While the turbo is different, the power curve shows you how far out it reaches. This was a not-as-aggressive as I would have wanted to be, but it had excellent street manners. I will NOT give out the cam specs so dont start asking me to post them! Every combo is different, and I will steer people through the proper channel to get a custom cam for their particular application/combination.

Now - turn it up slowly (remember to watch the plugs/tune) and enjoy it!

 

[randy merritt]

Re: SY 2373 Ramblings

New info if anyone is still looking. Went to dyno again today with front shaft in.

Results for AWD wheel HP are: 420 HP and 544 TQ with the TC manually locked via ALDL. Dyno chart to follow. Assuming a 25% drivetrain loss, that equals 560 HP and 725 TQ at flywheel. If you assume a 30% drivetrain loss (not sure which to assume, lots of opinions), that equals 600 HP and 775 TQ at flywheel.

Pretty good I think, and about the limit of my built 700r4. And my A/C still blows cold as hell. I am happy, and I give lots of props to Alex for the tuning. Running about 22 psi with zero knock at max rpm. Only reved to about 5k, seemed to drop off after that, prob. due to the 415 cam I am running.


FROM OLD POST:

"We did this test on a 600 hp build (engine dyno test) and in a stock wheel, 700r4, stock t-case Typhoon we lost about 30% to the wheels when all said and done.

The percentage does NOT always stay the same as it has many factors involved. But you can usually count on no less tha 25% and no more than 35% on average.
__________________
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Hardcore Performance for over 25 years
Custom Engines / EFI / Forced Induction Specialists
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http://www.syty.net/forums/showthread.php?t=43540&highlight=drivetrain+loss

My 30% number is based on the referenced post.

Enjoy.

 

[alwayscode390]

Re: SY 2373 Ramblings

WOW, your truck has REALLY gone places recently!!!

I like the hood vents a lot more than I thought I was going to ... now you cant drive it in the rain .

I like your wheels too ... but are the spokes angled differently on the rears and the fronts? Need to switch sides on either the front or rear tires ---

 

[randy merritt]

Re: SY 2373 Ramblings

The spokes facing different ways have been fixed. I have made some inserts to cover the vents in the event of rain.

 

[jpalmer]

Re: SY 2373 Ramblings

Nice work Randy!! thats some good power! Oh,and Alex sucks :rotf::rotf::rotf:

 

[randy merritt]

Re: SY 2373 Ramblings

Nice work Randy!! thats some good power! Oh,and Alex sucks :rotf::rotf::rotf:

I know he does. I still don't understand why he hates Cubans. I mean his screen name is QBNKILLER (Cuban Killer). I asked him what he had against Cubans, and he really did not answer. That is still a mystery to this day.

 

[randy merritt]

Re: SY 2373 Ramblings

shot of tp at speed

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[Quickstop [UK]]

Re: SY 2373 Ramblings

Oh I'm watching! I'm wondering how much benefit a cam would provide on your truck.

Nice job! What does that translate into at the track?

 

[randy merritt]

Re: SY 2373 Ramblings

Oh I'm watching! I'm wondering how much benefit a cam would provide on your truck.

Nice job! What does that translate into at the track?

we shall see later. I don't know what to expect, but hoping for mid 11's. BTW, I am going back to stock Ignition, as the MSD just causes to much grief. Truck ran better with stock.

 

[jpalmer]

Re: SY 2373 Ramblings

Just get your 60' down and you'll see what it does. reduce as much weight as possible but i can bet with a good launch and such you will surpass your expectations. Driver mod helps

 

[randy merritt]

Re: SY 2373 Ramblings

Here is my latest chassis dyno chart from 7-16-12. This pull was from a 60 mph steady state (about 2800 rpm) in third gear, then I went WOT up to about 110 or so mph (5000 rpm). It took a while for the boost to build to max with the TC locked, given the way that I punched it from less than zero boost at 60 mph. Not a pretty graph, but here it is. TC was manually locked, and I could feel a "surge" a couple of times during the pull.

 

[randy merritt]

Re: SY 2373 Ramblings

OK, went to the track today (Valdosta). I made four passes, and only ran the full quarter on the first pass, as the truck did not seem to shift into OD, and was revving quickly past 5500, so I kind of let off some, so as not to blow the motor.

Results:

best 1/8 was 7.566@91.66 mph.
1/4 mile on first run was 11.95@111.67 mph.
1/4 on best 1/8 run (coasting after 1/8 mile marker) was 13.209@64.46 mph.

My understanding is a lot of sy/ty owners would be happy with my 1/4 et on the 64 mph run, so I am happy.

I think I am done for now, as I am very satisfied for a driver truck (a/c and all).
This was running 20-22 psi, pump gas and alky. Zero knock at most times, with very brief retard of 1 or so degrees (mostly less). 60 foot times were consistently in the 1.7 sec range with launching at 3000 rpm and 10 psi. Track was very sticky, and I had no wheel spin. I think I may go again this winter when it is cooler and see if I can improve my 60' times.

 

[alwayscode390]

Re: SY 2373 Ramblings

Congrats on the 11 second run.

Now you just have to figure out your transmission issue and your set!!! ---

 

[Sean Krupa]

Re: SY 2373 Ramblings

Nice run, your truck definetely has more in it. ViciousV6 ran low 11's with a GT35r, Vortecs/Cam with about 16psi in a Typhoon.

 

[qbnkiller]

Re: SY 2373 Ramblings

Congrats Randy! Not bad considering you let the trans shift at 5000, smallish cam, and I think a soft trans at that. I know the weather wasn't that great (94* air temp and humid) and the tune is still plenty safe. Enjoy it for the summer and lets discuss over winter.