L67 F-bird

[murphinator]

I have a couple ls1 cars also and have friends that do also , some of them 4l60 cars and sub 2.0 60 foots are not hard on street tires , 1.6/1.7 on dr's and skys the limit on slicks with the right stall and suspension.Which leads to the question...

is 1st gear lower in 3800/4l60 cars than ls1/4l60 cars ?

 

[MNcarbturbo]

90% of my blame lies in the tires. They are olds used tires and the only reason I got those is Im putting snows on for the winter and I didnt want to mount and balance a nice set when they are coming off and then going on again. Plus its another $400 for them and ive got a set of 50% tred 235's for $35.

The other 10% lies within the drivetrain, but Im not going to doom the traction until I actually spend money on tires. These tires are a big improvement from the 215 snows that were on the car. It would spin if I was at a stop sign and I didnt ease onto it. And that was before I tuned the car wich made it run a ton better.

 

[KrisW]

For spring, start looking for a set of 245/50ZR16 tires. I have two Sumitomo and two Cooper, and either set works great. Changing up to this size totally changed the personality of the car.

As for the track, you should be able to get a couple of 4th gen 16 inch wheels cheap at a self service wrecking yard. Then you can put some good used drag tires on them, and just leave them in the garage.

 

[MNcarbturbo]

I was looking on tirerack and they have Kumho ecstas in 245/50/16 for $85 a pop which is affordable. Or $115 a pop BFG's but for $100 more for BFG's I have no issues buying kumhos. Should check out the local tire dealer to see what firestones are.

For drag tires I am thinking about running my 15X8.5 AR vectors I have sitting in my basement. They will stick out a bit but thats fine, Ill grow the mullet it I need. :biggrin:

 

[KrisW]

First off, you'll have to check, but I'm not sure that most 15" wheels will fit the 4th gen rear disk brakes. If you have drums, you'll probably be okay.

I have run the Kumho ecstas before, after seeing a test in Car Craft, I think it was. Maybe GM Hi-Tech. Anyway, they are great for the money. Just a tad on the hard side.

 

[Brad Zeidler]

Whether it's a V6 or V8 4L60 they are all the same. What I'm saying is that your et's will improve in any of these cars by sticking in those other planetary gears with the 2.84 ratio. Ask anyone that runs the 4L60 when it shifts from 1st to 2nd it really goes to the bottom of the powerband. If the gear split is just that bit shorter the engine will shift into a better sweet spot of the powerband and not have to climb from the very bottom. It's just too much of a change from 3.06 to 1.64 is 2nd I believe. Shifting from 2.84 to 1.62 will improve the et and usually aid your 60 foot times as well provided you have good traction.

 

[usetaboost]

put a stall in it

 

[KrisW]

I agree about the ratios, that's why I favor the 2004R above all other non electronic transmissions. You can build them to take high HP just as well as any other, plus have overdrive and that nice first gear. I have always been disappointed with that large spread on the 700R4/4L60E trans.

I can't access the link to the Minnesota website (because I'm not a member) but I am searching the referenced Car Craft article to find out who sells them. I have another Firebird that I would love to have that set in!

 

[KrisW]

Wow. That's a little on the expensive side...

I'd stick a 2004R with an adapter in there before I did that hahahahahhaha. Or, maybe the 5L transmission from the newer stuff would be a good upgrade.

 

[usetaboost]

Hey mncarbturbo, what do you think about bringing one of your cars to sioux city for rock n rods?

 

[MNcarbturbo]

Depends on when car craft is and when the big 2 day races are at the drag track an hour from me. If it works out I would consider it ut I am horrible about schedules and pre planning so I hate to give an answer until May.

 

[usetaboost]

Just wondered if you were interested. I'll keep you up to speed as the details come out. Keith has mentioned coming out here for it also.

 

[Blackpearl02]

I just stumbled across and have enjoyed reading your build up. I have thought about doing this and have been told that the L67 will not bolt up directly to the RWD trans. Here it is though. I look forward to seeing more progress on this hybrid

 

[MNcarbturbo]

Well I crashed it back in October but its fixed and back running again, much better looking I may add.

 

[usetaboost]

wow, nice job!

 

[KrisW]

Wow! what happened?

I am guessing that the boost did NOT help you correct the car before the hit...

Nice job on the repairs.

 

[vicious6]

Really enjoy reading this thread! Doing a great job with the Bird. You have great fab skills and have done a great job on the Bird!

 

[MNcarbturbo]

Thanks!

I have been driving it daily for a few months now. The MPG is dissapointing. I was hopping for 27 but Im only getting 16. Dont know why its so bad as I am using a stock Regal GS timing, fuel and air flow tables but theres a chance I missed something in the tune. The O2's are good, and the car pulls great, doesnt smell gassy without the converter. Its a mystery to me.

 

[charlief1]

Around town or on the highway?

 

[MNcarbturbo]

27 highway. The 16 is 95% highway.