Thread: L67 F bird

Have a 97 firebird with a l67 swapped in. Backstory is here.
http://www.turbobuick.com/forums/thr...f-bird.352126/

Goal when I bought it was to run mid 12's with full interior, AC, and be able to be driven 12 months a year in ND winters.

So since I'm too lazy to update everything from the beginning we start from now, haha!

Ran a 13.26 at 101 with a 1.75 60ft today. It was like 80-85 out with a pretty high dew point. By the time I got the tire pressure set in my DR's and got the launch set good the coolant was 210 degrees, IAT's were 110 so there was nothing really to be gained. I was flowing about 5 lb/min on the MAF less and made 2 PSI less than last week when it was 60 out and I was testing it. The heat killed it. I also was not getting the timing commanded by the ECM. ECM commands 10 degrees in the spark table and it was getting 15 at WOT. I bumped the timing up to 18 and it still recorded 15. I gotta see if theres a table screwed up or something or someway to get the timing bumped up to 20 degrees. Just adjusting the high octane table isnt doing it.


Last race is early october so hopefully I can show up with more timing and better weather not heat soaked and shoot for my 12.99. If I can get 12.99 on the setup it has now and add a few more PSI, 5 more degrees of timing, a little weight reduction, and maybe a light stall like 3000 it might get me to the 12.50 zone.

Overall the day was a success. Dropped .75 of a second over the 89 octane and 6 PSI setup. E50 and 10 PSI was cool to play with.

did you port the heads, or put a cam in it? looks like a lot of fun.

Heads are mildly ported. Basically had my machinist move the valve seats out a bit and cut the valve pocket out a bit to make a little smoother transition. Has an s1x cam also.

I've gotta figure out where the last .75 of a second is hiding. The car is heavy (3440 with an almost empty tank). If I could cut 200 lbs and get the IATs down and boost pack up and actually able to add timing it might be there.

squirt some methanol in there, more timing advance and lower iat's. or if you have E85, you will have to swap some bigger injectors and tune it.

I had methanol and it ate the teflon off the rotors. So more meth for me! Haha!

Ive got 60's and a walbro 255. Was running E50 to just transition to E85 eventually. My problem is there isnt any room between the cowl and blower so I can't ice the blower between races so I gotta find out a solution for that.

Originally Posted by Gutless

I had methanol and it ate the teflon off the rotors. So more meth for me! Haha!

Ive got 60's and a walbro 255. Was running E50 to just transition to E85 eventually. My problem is there isnt any room between the cowl and blower so I can't ice the blower between races so I gotta find out a solution for that.

your rotor coating was probably already heavily worn before the methanol.
and nitrous would for sure get you there, probably take 1 full second off your time.

Originally Posted by ScottyDoggs

cradle spacers and a ssic would make a world of a difference. no need to deal with all the axle geometry BS like on a w body.

what gear you got in the rear?

if you did this, you could use an icebox air to water intercooler, they work really well and are probably the best air to water intercooler available. you would never have any heat soak.

Ive thought about getting a ssic. Just a lot of work to get it to fit. I think it has 12.50's in it non intercooled. If I wanted to run 11's I would make an intercooler fit with an a2w with ice. I really want to hit 12's non IC and no nitrous.

I might try alky injection again next spring if I dont get 12's this fall.

Ive got 3.42's in the stock 7.5" rear and stock 4l60e. Thats the nice thing about the RWD setup, havn't touched the trans like fwd stuff.

I think the plan for this year is to get the timing to 20 degrees, get a set of front runners to take a little weight out, and build a water cooled pad or something I can fit in between the cowl and blower to cool the thing off a little. And hope for cooler air. If that doesn't do it I can get a 4cyl 4wd S10 converter that stalls to like 3000 for $100.

What about a nice P&P on the blower and LIM?

Go back to the meth injection, easy way to chemically intercool...it's magic juice! Forget about the damn coating in the blower, spraying meth in the case will help tighten up the tolerances and make up for the missing coating while cooling intake charge and the blower at the same time.

Interesting the teflon doesn't do anything. I thought it was pretty important. I might try it again. I was just using window washer fluid but have considered running meth/distilled water at 50-50 mix.

I could port the blower and LIM but Ive gotta drop the engine to do it since the cowl is in the way.

Switched to full E85 just to see what happens. Been dailying the car and runs just as good as it did on gas.

At 88% DC with my injectors so 60's was the right choice. With an IAT of 65 or so my MAF flows 45lb/min which is where I should be. I was so heat soaked when I raced a few weeks ago its good to see it does pick the power up in cooler weather. My ECM doesnt really function the timing it is commanded. I put a 20 degree WOT tune in and its going 24 degrees but no knock and 11.5 AFR gas scale so it looks fine to keep it there.

It might have a 12.99 in er as it sits!

Planning on going to the track again next weekend. I needed to order a drive hub to finish my m122 gt500 on an lq4 build so I just decided to order a whole 2.6" pulley kit and stick the 2.6 on the fturd and use the hub on my m122.

Needed to machine my snout down and didn't want to pull my snout off. Built a quick offset boring bar head and used an 8mm bolt in the snout to spin it off using my cordless drill.

Worked great, cut it down to 2.23" which should fit a 2.6" according to my rough estimations on my 3.4 and 2.8 pulleys. 3" aluminum shaft with a center hole, nub to attach the drill, and a set screw and boring bar.

2.6" pulley is delivered. Going to the track Saturday. High of 64 so as long as I hook I might have a chance for 12's.

My problem is if I run a 12:75 or something Im going to throw a 3000ish stall into it and try to run 12:50's.

Otherwise ive been dailying the thing. I ran out of gas last Wednesday going to the gas station. Ran out in the parking lot. Tried starting it too many times before I thought to check my fuel pressure gauge which showed it was out. I knew my fuel gauge was off but ever since I changed fuel pumps I found out its REALLY off. 1/4 tank is for all intensive purposes empty. Before it used to go to about 1/8th and then when it started going back up it was time to fill up.

But I get 12mpg exclusively city on e85. Starts in 40 degree mornings fine which is surprising since it hardly starts on gas at 20 due to my lack of a good iac valve and lack of cold start tuning.

12.93 at 105 was my best today with a 1.90 60ft. Track prep was minimal since it was street legal day. I had one 1.85 60 but the ECM defaulted to low timing table so it didnt run out the back end as good. Weather was excellent, light tailwind with 65 degree temps and low humidity.

If it ran a 1.75 60 like it did last month it would be a 12.60's car. Not bad! Track prep must have been way better last month, I never had a touch of wheelspin and this time it didn't matter what I did today it spun.

Picked up .3 of a second over last month with .15 worse 60ft. Only change on the car from last week was E85 instead of E50 and 18 degrees of timing vs 13-14 or so.

So now I gotta decide whats next. I ordered the 2.6" pulley and forgot it at home so I never ran it. Stall, that pulley, good track might run 12.25 (wishful thinking). Weight reduction for 11's????