New 98 owner question

[Hwy2Hell]

I have just recently inherited a 98 ragtop. It has had some after market work done and had a question.
It is a LS1 engine but I was told it has an LS6 intake manifold, how can I tell if it is the stock LS1 manifold or an LS6?

Thanx!

 

[c4c5specialist]

HI there,
There is honestly no real way to tell, other than confirming the part number cast into the plastic. It will be an 8 digit number.
Some installers will use a grinder, and grind out the ribs on the base of the intake, instead of changing the vent tubes, so you cannot really see if the correct tubes are there either.
Give us the number, and we can crossreference the number.
Just a sidebar, 01 and newer intakes are all the same, LS1 or LS6.
You can also reference this thread, in which picture are included, to assist in your checks of the engine.
http://www.corvetteactioncenter.com/forums/showthread.php?s=&threadid=19339
Allthebest, c4c5

 

[C5NGAGE]

Question, can we measure in some way the gap between the bottom of the Manifold and the valley cover even visually to determine which manifold is installed?

 

[Doneboy]

The manifold part number is located on the right side of the manifold, in the middle at the base. I do not have the correct part number for the stock or LS-6, but you can find out from the dealer.When I installed my LS-6 manifold, I could only tell a difference from underneath, looking at the bottom of the manifold. The LS-6 will be flat all the way across. Good Luck!!!

 

[Hwy2Hell]

Thanks for the help I will look into it.
One more question I have. I have read about the performance mode on the traction control. Was this not an option on the 98?
I have tried holding the traction control down for 5 seconds or even more but I never see a performance mode.

If this isnt an option is it best to just run with the traction control disengaged when I want perfomance out of it?

 

[c4c5specialist]

Hi there,
If you do NOT have the JL4 option, or active handling as it is called, you will NOT have the Competition mode.
That I believe is what you are looking for.
Allthebest, c4c5

 

[Hwy2Hell]

Ah I see, I have the FE3 Z51 Sport Suspension.

Thank you

 

[Hwy2Hell]

Ok I think I have found the numbers, they were on the passenger side of the manifold and they are as follows.
12556333

Thanks for the help, I'm just trying to find out everything about the car I can.

 

[c4c5specialist]

Hi there,
I will check on the number monday, as I am off until then.
Allthebest, c4c5

 

[Hwy2Hell]

Have a great weekend!

 

[Hwy2Hell]

Was anyone able to look up the number on this manifold and cross reference it?
Thanks!

 

[Pinstripe]

Ah I see, I have the FE3 Z51 Sport Suspension.

Thank you

For the record the active handling has nothing to do with the type of suspension you have. (ie Standard, Z51, or the electronically adjustable F45)

If you don't have a button on the console labled "Active Handling" you won't have the "Competion Mode" which is Traction Control off and Active Handling on.

Since Active Handling was an option in 98 you most likely don't have it.

 

[EHS]

Here's what I received when I swapped the LS1 for the LS6 manifold on my 2000:

Note the part number (88894339).

GM list price: $595.79

 

[Hwy2Hell]

Pinstripe,

Thank you. All I have is the button for traction control either on or off. I was confused when people were saying just hold it down and it will go to competition mode, this just never happened for me so I assume it isn't there.

 

[Hwy2Hell]

Here's what I received when I swapped the LS1 for the LS6 manifold on my 2000:

Note the part number (88894339).

GM list price: $595.79

Looks like my part doesn't match that. Was there a noticeable improvement in performance? $600 worth of improvement?

 

[EHS]

I actually paid $350 for mine from a vendor, not GM list, which is what dealers tend to charge.

My mods include the Donaldson Blackwing, stock factory airbridge and coupler, BBK 80mm throttle body, LS6 manifold, Corsa Indys, and the BPP MAF ends with airfoil (which have come on and off repeatedly).

With three sets of dyno tests with c4c5specialist on the Tech II, those mods produced 337 rwhp and 337 rwt, which on an MN6 car translates to 385 hp and 385 tq at the crank -- equivalent to a 2001 Z06. So yes, it was worth it.

However, here's the rest of the story: drivability in 3rd and 4th suffered in the 2,000 to 3,000 rpm range (although there was more raw horsepower, but poor throttle tip in and some "bogging" with rapid throttle applications.

So, we put back the stock MAF ends (with screen), gave up 10 hp and the equivalent torque, and got much better and crisper throttle response. For street driving, that's the better choice; at the drag strip, I'd probably use the MAF without screen for the extra 10 hp at the upper end.

I have photos and comments not only on the original LS6 and BBK installation, but also the dyno runs, and a fairly comprehensive analysis of the before and after (charts and all). If there's any interest on this forum, I'll be happy to organize those and post them.

Bottom line, yes the mods are worth it, and the car is performing exceptionally well. Credit to c4c5specialist for spending the time to get it all together.

 

[Tom Kearns]

Actvie handling is a "costed" option.
mode one = on (the default)
mode 2 -touch and release= off
mode 3 touch and hold while stopped= going ito competition mode, this means tires can spin but pitch and ya sensors are ON.

 

[TODD L GRIFFITH]

LS6 MANIFOLD

I put the two side by side on a table when I did my LS1-LS6 swap.
You cannot tell these two apart at all. I have a 99' so there is a difference, although I could not tell. If you want to replace the LS6 with an original LS1, I'll sell you mine for $100.00. Then it would have cost me as much as EHS paid for his......LOL!

 

[TODD L GRIFFITH]

EHS I can get you another 20hp

EHS,

With your modifications, you must be running fuel lean. My mods. are similar to yours, but do not have any of the problems you are having, because I have fooled my PCM electronically to think I am running lean, and the PCM has compensated me with enough spark advance to make me run 10% rich which translates to the right amount of fuel with all that air coming in. The Mass Air Flow Translator, A.K.A. "horsepower in a box" is what you need. If you do a web search for Mass Air Flow Translator, you will find quite a few sites that sell it, and people that have installed it. It made a large difference. My mods are:
6" K&N Conicle filter, 1000 cfm MAF ends, Vortex Power Duct, 80mm 1000 cfm throttlebody, LS6 intake manifold, relocated recalibrated MAT sensor, Coolant By-Pass, 160 degree thermostat, Jet Stage II chip, Borla Cat Back XR-1 competition exhaust, and the Mass Air Flow Translator.
The PCM doesn't know how much air you have, because alot of the air is getting by unmetered. My neighbor drove my Hardtop before and after the translator. After the translator was installed he came back and said "That thing is sick." Sick in a good way!
I paid about $250.00 for the translator. A great deal, and a steal for the amount of horsepower gain.

 

[c4c5specialist]

Hi there,
I can comment on EHS and his running.
He is at 12.8 to 1 air fuel ratio, at WOT. This is the best power producing air fuel ratio, for most any engine, but especially Gen 3.
We monitored all fuel trims, with Tech 2, live plot, and full OBD2 diagnostics in place. At 12.5 to 1, he dropped 11 horse, at 12.3, he dropped 23.
When running MAFT diagnostics a while back on 2 cars, 1 LS6 and 1 LS1, problems were experienced with the MAF signal to the PCM in both cases. Translators were installed by vendors of the MAFT. Issues were minor, however, it did cause slight drivability concerns, as there is just a full throttle setting, over the entire range, not base in a certain RPM. You are simply fooling the computer into seeing either more air, or less air, based on a given voltage and frequency.
While it may work better on heavily modified cars, on a base Gen 3 with slight boltons, it doesnt yield the best drivability under all conditions.
This is the reason I cannot recommend the translators in these cases.
Allthebest, c4c5