Well guy's its been a long ten months in the making, but finally got the LSX 427" installed and all of the bugs worked out for the most part. Took the 98 SS for the chassis dyno tuning session with Pat G. @ LSX Performance Dyno Tuning in Victoria, Tx. It was a long 12 hour day, 4 hours driving there and 4 hours worth of tuning, and another 4 hour drive home. But, I am very happy that everything went well and the SS is running much better now than off of the base tune it had been running on for the last couple of weeks.

Graph from the chassis dyno tuning session with Pat G. added below.

Pat G. did a great job tuning the car today, seemed to get most all of the little quirks lined out. As a reminder the engine is a LSX block built 427" with the TFS GenX 255 LS3 heads & FAST 102mm/102mm setup. Here's a quick list of the parts used in the build
Engine specs are:
GM LSX block
Callies Compstar 4.0" stroke crank
Callies Compstar 6.125" rods
ARP main & head stud kits
Wiesco K463x125 -2.8cc forged pistons/ 12.0 compression w/65cc chambers
Cometic .051" head gaskets
TFS GenX 255 LS3's milled to 65cc Chambers, no additional port work
Pacaloy 1208X dual springs w/titanium retainers
FAST LSXR 102mm/ FAST 102mm TB
52 lb injectors/ ZL1 Camaro
Cam Motion billet core Hyd Roller Camshaft
248*/264*@ .050" with .694"/ .681" lift on a 112 + 4 LSA
Comp Cams short travel Hyd Roller lifters
Manley 3/8" x .120" wall pushrods
Crower Stainless Shaft mounted 1.8 ratio rocker arms
Rollmaster double roller timing set
Melling 10295 ported oil pump
Moroso 21150 F-Body Aluminum oil pan
ATI F-body damper
Kooks 2" x 3.5" merge collector LTs
Exhaust 3.5" Y-Pipe into 3.5" x 4" Flowmaster merge Y, 4" I-Pipe with 4" Vibrant Performance resonator, 4" over axle into a 4" Magnaflow race muffler.

The engine put out about 650 HP & 580 lbft of torque on LME"s engine dyno.

The car has a GM Performance Parts 4L85E tranny with FTI 9.5" Billet triple disc converter with approx. 4800-5000 stall and a Moser 12 bolt rear with a full spool and 3:73 rear gears. I don't think its what you would call a dyno queen car, as the driveline soaks up some power compared to a stock F-body.

Anyway, when Pat G. e-mails my dyno sheets to me I will post them up. On the Mustang dyno the car put down roughly 545HP & 530lbft of torque at peak #s & timing at 28 degs. Seeing as the car will be run on 93 octane pump gas, we decided to cut back to 26 degs of timing to remain safe on the tune as the warmer weather will be coming soon. Will be looking to spray a 150-200 shot on it here soon too!

The car is at roughly 3850-3900 raceweight as it sits now! But, after unloading off of the trailer and making a 2 mile drive to the house tonight.
HOLY $hit! This old heavy pig will roll out son!





Here is the graph from my chassis dyno session with Pat G. tuning the LSX 427" in my 98 Camaro SS. The car is a full weight pretty well optioned out SS with a 4L85E tranny/ FTI 9.5" Billet Triple Disc conv/ Moser 12 Bolt 3:73 rear, full BMR & Spohn suspension. Race weight is a hefty 3875-3900 lbs depending on how much fuel is in it.

We left some power on the table by keeping the tune a little on the safe side. The tune is a SD tune, we had the power up in the mid 540s and torque close to 530. But, in the name of safety Pat G. and I both agreed to keep it safe ( considering the 12.1 compression on 93 octane pump gas ) and backed the timing down from 28 to a safer 26 degs to better cope with the inconsistent 93 octane pump gas and with the coming hot summer temps. We also left the AFR a little on the fat side as well around 12.4 in the name of safety also. I would rather sacrifice a few ponies rather than deal with the ugly side of the what could happen.

 

I remember the engine build!! Good results especially threw a auto tranny!!

 

nice , cant wait to hear some numbers , why a 4l85 and a 4l80?

 

The #s will be about 541 rwhp & 530 rwtq through the 4L85E & 12 bolt 3:73 spooled rear.

When I bought the car 2 1/2 years ago it had a 4L60E in it that was starting to show signs trouble. The previous owner had the tranny worked on a couple of times already & I just was not comfortable sinking more money into a lost cause. I am not saying that a 4l60E cant be made to live, but I have seen way too many of them fail once you get over 400-450 rwhp.

With the previous setup 6.2 engine & 150 shot I was at 600 rwhp or so. It was only logical for me to upgrade to a much stronger tranny. The 4L85E was bought brand new from GM and has a little more torque capacity than the standard 4L80E.

 

Nice job OP. Looks like a very well thought out build. It's going to be really hard to handle on the sauce.

 

Thanks, and agreed on the street it will be brutal on the juice

At the track, the car will work much better with a prepped surface. I do have a progressive controller for the nitrous setup to help soften the launch on the " sauce " at least that's the general idea " fingers crossed "


The car does have all the good suspension parts underneath though. Has full BMR tubular K-member & lower A-arms up front with Afco DA coilover shocks. In the rear has BMR adjustable lower control arms, panhard bar and relocation bracket along with the Spohn Extreme Duty Torque Arm, BMR Extreme Duty Anti-Roll bar and Afco DA coilovers.

 

I think you'll be set at the track. Your suspension setup sounds good. I just got the Viking DA coilovers for the front and rear, and am looking forward to testing them out. What progressive controller do you have?

 

I have the NOS mini progressive controller. I used it some last year, but never really got it totally sorted out. But, I was also having issues on the launch with the Tru-Trac differential handling the torque spike on the launch, would want to push the car to right every time.

I now have changed from the Tru-Trac w/ 4:10 gears to a full spool and 3:73 gears. So, now should be able to make a full pass on the juice without running out of rpms. I was mph limited with the 4:10s @ 6800 rpm to about 131.5 mph about 75 ft before the traps. Now, I should be able to make a full nitrous pass and achieve way more mph.

 

Very good numbers. I see you have a crankcase vacuum pump.

 

Thanks, #s could be better but the drivetrain took about 15% off of the engine dyno #s. Lost about 100hp & 50 lbft of torque. But the ole car sure feels strong and will roll out pretty hard. Might get a chance to take it to the track this coming weekend. Weather supposed to be sunny & low of 40 deg/ high of 59 degs. Great racing weather!

Yes sir, it was an added expense for sure. But, I think in the long run it will prove to be a wise decision. Whether or not if it added any HP, it will surely help keep the crankcase pressure under control and hopefully help with keeping the gaskets and seals doing their jobs better.

 

Flowman
Congratulations and great results!
Very curious as to your RPM @ Peak HP as I am having a
LSX built with TFS LS3 Heads & a CAMMOTION Cam also (LLSR).
Who specced your cam? looking forward to your graph and
Track results! I hope that both your track and street expectations are
Exceeded!

 

Thanks, I really appreciate that!

I had expectations of around 700hp, but it is what it is. After driving it a little earlier today, this baby rolls pretty nicely

Peak power occurred around 6450 rpm and peak torque is around 5300 rpm if I recall correctly from LME's engine dyno. I went ahead and let the guys at LME spec the cam since we worked hand in hand to select all of the other components. Cam specs are 248/264 @ .050" .691"/.684" int & exh on a 112 +4 LSA.



There are dyno graphs of the runs on the engine dyno in one of my earlier threads.

The cam was selected to stay within the limits of where the FAST 102mm intake would dictate where power would tend to peak, which is usually in the 6400-6500 rpm area. There was no need to cam for higher rpms as the intake would only choke it down up higher anyway. That is one thing nice about this combo, you don't have to "ring its neck" to get the power out of it. They did dyno the engine with a Holley High Ram & 90 mm DBW throttle body also the Holley intake did make slightly more peak power up around 6800 rpm or so and carried the power pretty flat until 7100 or so. BUT, the FAST intake killed it from off idle to the 6400 rpm point. I'm talking as much as 20-30 lbft of torque at most any place in the graph.

 

Flowman
Thanks for the reply! Three other quick questions if I may,
Is the FAST 102 Ported?
How big of a N2O shot will you run?
Was your cam specced to N2O in relation to the 16* Exhaust
Split since the TFS LS3 heads have a better E/I flow relationship
Then most Square Heads? ( I plan on a 100 shot at most )
How much more HP did the Holley with 90 MM TB make peak to peak?
Sorry that was 4, :-)
Thanks Again

 

The FAST 102mm was not ported at the time of the engine dyno, but I did do some home porting on it before I put the engine in the car. I did a nice port match on the lower base to the head ports, and then matched each intake runner to the base. Finished off by trying to better blend and radius the bellmouth openings of the individual runners. Don't know if I helped or hurt it, but I didn't get too crazy with it. I have port matched quite a few old school single plane intakes in the past, so I think it came out pretty good.

I will start out with a 150 shot, which is what I used on my previous engine. I might go as high as 200-225hp shot.

No, the cam was not spec'd as a nitrous cam per say. But, I did let them know that I would be spraying around a 150-200 shot. I think maybe the idea was to make it run well on motor, and a smallish 150 shot or so is not so critical that the cam needs to be spec'd just for the nitrous. I kinda think maybe he held back on the intake duration intentionally to keep the power peak in line with the rpm range of the FAST intake, and the exhaust side is needed for the cubic inches and 12.1 compression to be sure it exhales properly. I'm no cam guru, but what I had in mind was only off by about 2 degs duration on both int & exh sides from where he was and I was thinking a 113 LSA, where he decided on a 112+4. Who knows if its the best it could be or not, but we will see how the real test at the track turns out.

Here is one engine dyno graph showing the comparison of the Holley High Ram vs the unported FAST 102mm intake both with 90mm DBW throttle body. The Holley intake is the Red lines, and the FAST 102mm is the Black. As you can see, the FAST 102mm kicked *** everywhere except on the very topend.

 

Good to see you got it tuned. I noticed you went SD. I am currently waiting on my SD tune from Pat G. Should be a hard runner, Congrats!

 

Dang flo looking sweet very nice build I've been poking around on here lately just started tearing white car down gonnA do a max effort 346 on orange car with tranny rear and motor out of white car kinda got an itch again your motor looks awesome I bet it sounds great too I need to come check it out

 

Got a me a clean truck to drive so I can work on my junk want to get skinner to grind me a trex style cam and get him to tune it tired of driving that junky white ss gave to my boy when your at the house call me so I can come check it out 5532048

 

Yeah, was glad to finally get it done. Pat G. talked me into going SD, and I think its gonna work out okay. Was hoping for a little higher #s, but I am going through a 4L85E tranny & 12 bolt rear. We also see that the engine is pulling a vacuum in the upper rpm range, so I still have a restriction in the intake tract somewhere. I think I might have to do away with the 104mm lid and fabricate a full 4" intake system.

Hey Man
Good to see you back on here, been a good long while. Hope to see you get that ole " Hugger " car bucking & snorting here soon. That will be an awesome car with a nasty hard hitting stick in it. Gonna be 6spd or auto?

I made a few passes at Evadale about a week and half ago. Gotta tweak on my tranny shift points, 2-3 shift was coming too early by 300-400 rpms. My 3:73s are not great for a motor pass either, crossing the lights around 5900-6000 rpms so leaving quite a bit on the table there. Plus the ole heavy pig with me in it is between 3850-3900 lbs depending on how much fuel is in it. Gotta play with the launch and see what the converter likes again now.

Best pass was on a crappy 1.62 60 ft. Ran 10.78 @ 127 mph, 1/8th mile was 6.90 @ 101.70 mph. That less than stellar 60 ft & only crossing up around 6K blows. Car should have some 10.40s in it with a decent 60 ft. May end up going back to the 4:10s, but these 3:73s will be badass on a 150-200 shot

 

Going braked A3 it's just too good on motor. I know you'll get that car where u want it I bet that thing sounds awesome. It's an awesome build for sure, you get time roll by off fri sat and sun most weekends

 

What is the map sensor telling you? How much vacuum? I'm chasing a restriction as well