Any L67 pros?

[MY FYN 79]

I'm looking to add a car and just trying to get a little info on some different drivetrains out there.

Is there anything in particular to look for in an L67 powered car? Also, do they absolutely have to run on 93, or can cruising still be OK with 87 or 89?

Thanks for any thoughts!

[PB86MCSS]

Weren't there a bunch of guys on here running modified GTP's a few years back? Apparently all L67 owners dissapeared from this board. :goof

[theavenger333]

if they're been modded at ALL, the trans will take a poop at or around 100k. period. Some cars will run with little Knock Retard(KR) problems on 89 and below octane, but some run terrible. only way to know is with a scanmaster or some other scan tool. my GS now runs with about 1.5 degrees of KR with minimal supporting mods and a stock pulley with 91 octane. i wouldn't run anything lower cruising or not.

[A B4C Z]

Jeff had one that went 12s back about 8 years ago. Could always tune it for 87...if you need we can do it at lmt.

[team beater]

I run an lightly modded l67, I suppose if you never get into boost you could probably run regular. I personally wouldn't do it, if you are looking to avoid the higher gas prices like said above get a tune or maybe a na 3800. Ive got over 100k on mine with no tranny problems, from what I understand the trannys becomes the weak point when you start putting out more than 300hp and/or slap a set of slicks on. I'm pretty satisfied with mine, not necessarily fast but fun enough for a dd.

[Taetsch Z-24]

The price difference is 2 bucks for 10 gallons.....

[Cryptic]

The person I sold my GTX too destroyed it running 87 octane. 3.25 pulley and reprogrammed Pcm.

Don't bother with a supercharged motor if you don't want to pay for the gas.

[PB86MCSS]

Probably $100-200 per year more, depending on your driving I'd say.

[MY FYN 79]

Thanks for the input guys. I kinda had a handle on how much more it would cost per fill-up ;) , but its good info to know that premium is the best bet for the blower cars.

[Dr.Buick]

you could always tune it for E85

[BadAzzGTA89]

If it is modded I say run 93 if you like your pistons..
The tranny is better in the 02-03 cars with the hardened 4th shaft.
And yes you could always throw bigger injectors in with a tune and run E85!

[PB86MCSS]

What kind of gas mileage do you L67 guys get, city/mixed and highway?

[theavenger333]

mixed/city i get 18-20. highway i've gotten as good as 30, but consistently in the 27 range. depends on how nice i'm driving

[BadAzzGTA89]

i get 34 hwy and 27-28 city but then again im on a tune.

[theavenger333]

l67 cars all have minds of their own. they all run completly different, react to mods differently, get different mileage. my 99 GTP ran extremely well, and got much better mileage then my Regal does, more similar to the above. it also was faster at the track then a few 3.25 pulley cars with a 3.4.

[team beater]

mixed/city i get 18-20. highway i've gotten as good as 30, but consistently in the 27 range. depends on how nice i'm driving


This

[MY FYN 79]

Ended up snagging an 01 GTP special edition with 91K on it. Spent a few hundo going through it right away (intake gaskets, complete tuneup etc) and it runs pretty good. As far as mileage, I've yet to see the "instant" mileage display go over 18. Are people gauging their above mileage numbers off the instant, or actually calculating them from fuel used? I'm a bit skeptical.

[theavenger333]

uh the instant and the DIC will never be correct. It's an average from the miles you have plus its very inaccurate. only way to get true is to calculate it at your fillup yourself.