gtrslngrchris

328 seems awful high but then maybe my dyno was low. I showed 321/370 with lt headers, full borla exhaust, ls6 ported intake manifold and vararam.

4XLR8N

The results are in...here are the numbers from the dyno:

• Baseline was 311 rwhp and 325 ft/lbs torque

• Final was 324 rwhp and 331 ft/lbs torque

My observations before driving it, just looking at the dyno sheet:

• I was slightly disappointed in the max power, although it was pretty close to what I had expected (as I thought about it further, my 330 – 340rwhp guesstimate did not take into account my switch from 5W-30 to 15W-50 oil weight, which could easily cost 5 hp, so that may explain it)
• The baseline run shows a significant drop in torque/hp @ 4100 rpm (about 25 ft/lbs and 15 hp); that power deficit remained throughout the rest of the rpm band. I do not know why, but can guess that my mods, even as mild as they are, took the engine beyond the windows of the OEM fuel/spark mapping tables in the factory tune above that rpm. The good news is the dyno tune took care of that.
• Fuel cut-off was 6200 rpm, it is now 6600 rpm
• Overall, the area “under the curve” has been significantly improved, especially at mid to high rpm, which is exactly what I wanted to achieve

Driving observations:

• Definitely more responsive to throttle input now – my other big objective
• A couple of runs to redline definitely shows the dyno tune woke her up, even though the dyno sheet might not make you think so. One run where I was getting on it hard, but not trying to do any kind of burn out, was nothing but tire spin in first gear and hazing the tires all the way through second

So, bottom line – it was worth it. I now have what I wanted to have…the best running, most responsive (basically stock) LS-1 I could get. This fits perfectly into the theme of the Grand Sport project.

Below is a pic of the dyno sheet. They did video the last dyno run at my request. I do not have the file yet, but will post it when I get it.

July 28 - update...

It took me a lot longer to get the video than I expected it would...nonetheless, here it is as promised...

https://docs.google.com/a/livernoism...a1k/edit?pli=1

...baseline numbers include the Callaway Honker CAI and B&B Triflow cat back already installed...

540i 6spd

What's going on with the dip at 4200 RPM?

4XLR8N

Fortunately, nothing now - after the dyno tune it is gone!

However, what someone else mentioned is that the MAF becomes the primary input for air/fuel above 4000 rpm. It would appear that the mods I have done, even as mild as they are, took some of the air/fuel requirements of the engine beyond the OE tune's mapping.

4XLR8N

Here is an update to the C5 Grand Sport project, the latest work focusing on the suspension and brakes:

• C6 Z51 Sway Bar Kit w/metal end links
• C6 Z06 Shocks
• Lowered on stock bolts front and rear, removed 1/3 of rear bushings
• GM C5 OEM Speedline Z-06 wheels (17x9.5F, 18x10.5R)
• Nitto NT05 (P275/40ZR17 and P295/35ZR18)
• Schrader 28006 TPMS sensors
• PowerSlot slotted rotors
• Hawk HPS pads
• Russell stainless steel brake hoses
• AMSOIL Series 500 DOT 3 brake fluid
• Painted calipers w/VHT Real Red

I have a little over 20 hours into making these mods. I am sure there are others who could have done it faster, but I am slow and meticulous …no matter…I am quite happy with the results.

I drove it a little this evening to burnish in the new brake pads. Car corners as flat as a pancake! I will let the suspension settle for a few weeks and then have it aligned.

Attached are a few before and after pics...

4XLR8N

Here is a quick full side shot I took after the shakedown run today...

4XLR8N

Thought I would share a couple of quick updates on the GS project...

First, finally got the Elite Engineering catch can installed. First issue - I was sent mounting hardware for an LS3. Second issue, once they sent the correct hardware, was that the upper bolt hole was blocked by some casting material about 1/2" in - so I finally decided to simply cut the bolt with my dremel...final install came out fine.

Second, started on the interior work by tackling the seats.

• I installed the rocking seat fix kit from JW Motorsports on the drivers seat (pic of the offending rubber spacers that cause the problem).
• Since the passenger seat is manual, no fix needed on that side.
• Then proceeded with new foam from Vette Essentials and seat covers from DJ Motorsports (as you can see in the before/after pics, I converted from base to sport style seats).
• The only issue encountered there was the need to drill the six holes in each seat frame for the halo and insert cover pegs.
• In the last pic, you can see quite a difference in the fit of the covers.
• They both looked the same after the install. The difference is that I spent about 90 minutes working the leather with a heat gun on the passenger seat.
• Still need to do the drivers seat.

Once I get the seats done, it will be time to install the goodies that just arrived from DoubleD mods, including a Kenwood amp and sub and Helix speakers for the doors. Then finish up the interior by installing the seats and all the other interior goodies that came with the leather covers.

More to come...

4XLR8N

The Grand Sport mod-fest continues with the audio upgrade from DoubleD Mods and Dynamat from Summit Racing Equipment.

Main audio components are:

• Kenwood XR700/5 channel amp
• Helix B62C component speakers for the doors
• Kicker coax rear speakers (installed previously)
• Kenwood 10" sub in stealth sub box

I retained the Bose HU and, when all is said an done, it will look entirely factory with the exception of the amp on the rear panel. I could have hidden it behind a seat, but elected not to for better amp cooling and so as to not restrict seat movement.

Only issue is that, after all the install was done, the RF speakers do not work. Wouldn't ya know I figure this out about noon on Friday and, when I called Dennis, got a message that he was on vacation from Friday morning until Tuesday. I think I know what the problem is (amp integration interface module) as I can move the problem back and forth from RF to LF, but am hoping Dennis will call me back tomorrow so we can figure it out for sure.

I could not figure out a good way to install dynamat on the doors, but the rest of the car was pretty straight forward. Just a lot of work!

More pics to come once I get the console buttoned up after fixing the RF speaker issue.

4XLR8N

Talked to Dennis at Double D Mods yesterday morning - he said 90% of the time an issue like mine is caused by messing up the speaker wiring on the output side of the amp.

Double checked everything last night when I got home - everything was wired correctly. Dennis spent about 20 minutes on the phone with me doing some additional diagnosis and we wound up right where I thought we would - new amp integration interface module now on order.

Dennis said it is very rare for one of these components to have an issue. Man, if I had a dime for every time I have heard that in my life - always seem to get the "geez, NEVER seen that before" kind of situations.

Anyway, will post up results when I get the module.

Meantime, it is back to Livernois Motorsports to get the speedo calibrated with the new Z06 wheel/tire combo and get the fuel cutoff reset to 200 mph (forgot about that when we did the initial dyno tune).

Once I get the interior/audio done, we'll be rounding turn 4 on the GS project!

1bdvet

4XLR8N

Well...almost 3 weeks later (more than a bit frustrated about that ) the new amp integration interface module showed up today.

The good news - that fixed the issue and the system sounds absolutely great!

The system looks OEM stock (which is what I wanted) with one exception - the amp. I attempted to make the amp install as neat and factory looking as possible. The cargo net does a nice job of camouflaging it!

The interior is now back together as well, so here are a few pics of the amp and the interior in general...

4XLR8N

a few more pics...

cvm

More pics; C5 sizes or C6?

OP nice job

Thx for the space, Mark

martyb

I had a similar approach on my 98. Did flared rear fenders and GS wheels, wanted to make it look like a factory widebody which is why I stuck with GS wheels. I am thrilled with it.

4XLR8N

^^^^

Looks great!

I'm not sure I want to convert to the widebody fenders, but I gotta admit they do look killer!

4XLR8N

She's done!

4XLR8N

A few more pics...

funnyguyMI

Well done! The stripes on the center console is a great touch.

donald4972

OP, you've done some wonderful work here. Very tastefully extending a Corvette tradition (Grand Sport), that did not happen in C5 generation. Wish it would have.

I think understanding tradition in Corvette history, and understanding the excellence each generation played in that, is an important part of this hobby we love, America's Sports Car. I read somewhere, how can you contribute in a meaningful way to the future, if you don't understand the past. Seems to apply here.

I like your attempt to contribute to that. Well done.

You've come up with a good plan, stuck to it, and IMHO, done great work. And ended up with a beautiful C5, made tastefully better. I would SuperCharge it, and get bigger wheels (GrandSport like) and tires on the ground next, but that's me. You can always reserve your right to change your mind about that, later.

I've contemplated some of the interior upgrades you've done. Except where you have red, I'd thought of silver/gray for my 2003 Quicksilver metallic. And I'd (maybe someday) add silver/gray carpet throughout.
I think, again, the changes you've made are very tasteful, and not 'overdone' at all. Ever thought of a light gray carpet?

Anyway, congrats on a project seen to completion by you. Your C5 looks great, and is certainly your own, and somewhat unique (very cool). For now.

What next? Cause it never really ends.....

Don

540i 6spd

Great presentation! !!