JMB

Disclaimer.....yes, it's my LS7 Monte Carlo again but just remember before you poop on my parade, all I have to do is unbolt the top end and put it on my 2011 Z06's short block along with the cam/lifters, a modified hood and headers/exhaust and it's the same set-up!





Needless to say that I have a very big grin on my face for finally achieving a goal that I set out for myself long ago…..and the final numbers are in, 704/545 SAE RWHP/RWTQ for my 1988 LS7 Monte Carlo SS! I have posted my previous best results using the same Beck Sheet metal intake and NW 102mm TB at 680/540 SAE RWHP/RWTQ. And just for reference, when I started my horsepower assault the baseline crate motor numbers were 487/468 SAE RWHP/RWTQ! All three of these runs are compared below:



So what did it take….I switched out my Greg Good cylinder heads to a very special set of hand crafted GM LSX cylinder heads ported by Darin Morgan that he made for the Engine Masters Competition but never entered them in a competition. These are likely the best flowing GM LSX LS7 heads on the planet as well….here are the numbers from Rehr Morrison’s flowbench:

Lift / Int. / Exh.
.200 157 115
.300 229 158
.400 298 198
.500 351 220
.600 395 236
.700 409 243
.800 420 251
.900 423 254
1.00 429 261

I also changed my rockers from Jesel to Crower at Darin’s recommendation and these heads have 2.25” intake and 1.60” exhaust, both Titanium for the ultimate high RPM lightweight valve train, especially when combined with the super small 1.300” PAC 1335 springs with a plenty stout 860 lb spring pressure open. Darin also performed some special welding on these heads to help minimize valve train deflection and a side benefit was enabling me to up my pushrod size from 3/8” to 7/16”.

There was a minor miscalculation made when the heads were being final milled for combustion chamber size and they were cut to ~59.2cc’s which inadvertently bumped my SCR from 11.79 to 12.78 which I know likely lost some CFM’s but the trade-off came back in the form of added power due to compression gain. The only other downside here was that I was previously running straight 92 octane pump gas at 11.79 SCR whereas now I added a smidge of Torco, just to be safe! I didn’t change my tune at all as far as timing and actually backed out 8% fuel above 5500 RPM at WOT.

And for all of the doubting Thomas’s out there who never believed that someone could build this powerful of a NA motor using a stock LS7 short block, single throttle body and pump gas because the chassis dyno that I used must lie let me tell you that Darin ran these heads on a 431” LS7 motor with a smaller hydraulic cam that mine with 11.5 SCR and it made WELL over 800 FWHP on an engine dyno (I’m not sure if Darin wants the exact number published so I will respect his privacy and leave the number at 800+).

I am also VERY pleased to say after MANY months of frustration and several very fruitless trips to the track this past year I finally resolved my WOT speed shifting problems where with the help of several Forum Members we determined that the Torque Management settings for the E38 PCM were limiting throttle position to 35% after each quick shift (meaning that if you shifted less than 1 second between shifts you wouldn’t have a problem but any quicker and you would have to fully let off the throttle before you could go WOT again!). And with this solved courtesy of the chassis dyno where I could validate the fix I did actually have the opportunity to take my car out to the track last month at Pacific Raceways in WA State! I am embarrassed to say that between a tool box, ¾ tank of gas and several other weigh adding measures like larger radiator, exhaust, etc., my actual drag-strip weight with me in the car was a very portly 3850 lbs.!!! As I suspected, I only got one shot at a full run through all 4 gears before I got called out and promptly booted from the track….the one and only full throttle through all the gears pass was a 10.79 @ 133.75MPH with a 1.76 60’ time. I know the car has more MPH in it but this was a shakedown pass shifting at only 7500 RPM. I was using MT 295/45x17 DR’s and launched at only 4000 RPM to ensure that I wouldn’t break anything and actually be able to get in at least one full pass since I have taken so much crap from so many people for not actually being able to run the car WOT at the track. The only real disappoint was the video camera wasn’t working for the 10.79 pass but I was able to convince the track owner to let me make a couple of 1/8 mile passes to back up the 1/8 mile MPH so that the Doubting Thomas’s wouldn’t call me out again and say that I never backed up this pass and at least these are on video so that you can see and hear how the car runs. For some reason the car was running excessively rich on the 10.79 pass (actually billowing black smoke) and you can still see evidence of this on the video of the 1-2 shift run afterward. I suspect that the car may have been running on the cold-side since I was having problems trying to keep the car cool in the staging lanes and elected to keep shutting off the motor and run the electric fan to keep the water cold.

To recap the car has a Son of Transzilla T56, RPS BC3 clutch and Moser 4.11 12 bolt. The full motor spec’s:
• 100% stock GM OEM LS7 crate short block
• Solid Roller Cam by Bullet Racing Cams

• 258°/273° @ 0.050”; 112° + 4° LSA, installed 108.5°
• 0.781” intake / 0.747” exhaust
• Isky EZ-roll SR lifters
• Smith Brothers 7/16” pushrods
• Crower shaft mount 1.8 rockers
• C5R Timing chain
• Crower adjustable cam gear

• Beck Sheet metal intake

• Nick Williams 102mm throttle body
• Injector Dynamics ID1000 injectors
• GM LS7 MAF cartridge
• 4.5” diameter inlet tubing with K&N conical filter

• Exhaust system

• 1-7/8” to 2" to 2-1/8" primaries (round port, not D-port!) Triple stepped headers
• 27” primary length with 4” diameter merge collectors
• 4” diameter head pipe with 4” diameter X-pipe
• Full 4” exhaust w/MagnaFlow 12909 3-1/2" mufflers and 3-1/2” tailpipes

• Meziere electric water pump
• ATI 10% under drive crank pulley
• Two Elite Engineering catch cans
• 2.5 BAR E38 PCM tuning

And what everyone has been waiting for, the track video’s (unfortunately the 10.79 pass is missing but you get the idea!)

Chance42

Damn those heads sound nice! Making me want to spend more money here.

FSTFRC

Awesome build, you have maxed out this combination

RamAir972003

I need to talk to you Darin Morgan cleaned up my heads, and with the cam I have I am very very pleased what it put down pm ur number I'm 20 min away from Darin so I would love to be where your at lol. I'm still running stock intake ported by him also, waiting on dynos between the mad or Halltech that's coming out soon. Very nice I bet it pulls nasty.

DaOtherOne

Sounds great

londonk

I remember this car from awhile back. I want to say i saw it on ls1 tech or on here its been sometime now. I remember thinking how great this car was. Was it not for sale at one point? This combo is brilliant! May we see the Beck intake? How would a guy like me get a set of those heads? my final question is how do you like those rockers? congrats on the car

JMB

Thanks for the props guys.....this has been in work for a very long time and it's nice to finally see some results!

Never!
Thanks, the components are very carefully matched and the results speak for themselves....here's the pic of the intake below:



Just call Darin at Rehr Morrison 855-467-4880 but be forewarned, they won't come cheap!

Seem to be fine...haven't noticed any issues!

Here are the triple stepped headers and 4" exhaust as well:

JETninja

I think the Z would need a new Hood!

You keeping the C6Z?

JMB

I'd like to but too many cars.

Agreed!

robz

Nice going.
We made similar numbers with a destroked ls7 years ago.

JMB

Thanks robz, I'll bet that must have been a high RPM screamer!!!

robz

For sure.

I can appreciate the tremendous thought and planning that goes into such a solid build.

Enjoy the car. Sounds like you'll be having a lot of fun on the street and strip.

TRSCobra

Nice numbers; I hope to see the car in person at SIR someday! Who did your tune?

Chance42

Also, would you mind going into more detail about the problem/resolution to your speed shifting issue? Thanks.

JMB

Thanks! I got the boot from the lead tech inspector so unless I put in a full cage, lap/shoulder harnesses, etc. I can't run again. I perform all of my own mechanical work and I personally tuned the motor on the dyno.
This was a real strange issue that literally had me baffled for almost a whole year! Ever time I would go to Pacific Raceways all I would do is embarrass myself because when I would speed shift the car the motor RPM would freeze between gear shifts because it was only seeing ~35% throttle position whenever my shifts were quicker than 1 second between shifts....I can actually speed shift about as fast as Ranger (175-200ms). I would have to let off the throttle completely and nail it again in order for the car to continue down the track at WOT....very frustrating to say the least!

There is a table in the E38 PCM (see pic below) under Engine - Fuel - Cutoff, DFCO, and a section for "Control Method" where I had to set the ETC and spark to "Disabled" and set Fuel to "Enabled". After that, right below those 3 choices there's "Switchover Delay". I had to click on that tab and set the entire table to anything above the OEM setting of 5 so I set mine to 25 across the board. Problem solved! I can speed shift to my heart's content but it also disables the rev limiter for some unknown reason! See below:




Hope this helps!

Chance42

Thanks. I had some delay when flat footing it on my 1-2 and 2-3 shift, 3-4 seemed fine though, so I thought maybe it was me. I changed that and my cutoff rpm hyst to 25. We'll see how that feels. I have mine set to spark cutoff, but I may switch to fuel or do both fuel and spark.

Strange that your limiter is disabled, though. I'll have to keep an eye on that and be mindful of it.

Thanks for the help.

JMB

You're welcome and good luck!

spra4u

Very nice setup!! Great run!! I spoke with Darin Morgan a few months back and he told me that Reher Morrison had dropped the LS7 Program because they were to busy. Has that changed as of late??

Mike.D

wow. Congrats on your numbers. That car looks and sounds awesome.

djfury05

I spoke to them about 1-2 weeks ago and they said they still hadn't started it back up yet and didn't have a timeline either.