[RocktimusPryme]

Got up to Indy on Saturday for Injun Wars. We got pushed aside by their regular race and our bracket just turned into a test n tune. But I still got down the track and put down my best time. Previous best was an 8.1 in the eighth @88.7 mph.

Went 12.2 @109 with a 7.8 @88. This was also my first 1.7 60’. I told myself I was going to be happy with anything in the 12s, so bottom 12s made my day.

I think a lot of that 3 tenth improvement in the 1/8th is track prep. My previous time was at a small mom n pop track. Which is fun, but I don’t think can be compared to Indy which is one of the premier drag strips in the US.

I still think there is meat on the bone to get in the 11s. Other than subframe connectors I have zero traction control devices. So some Caltracs and or adjustable shocks could help. I also think I could launch harder. One of my remaining weak points is a 1310 joint at the rear end. So I’ve been wary of going all out at launch.

This continues to be on the 3.08 gear set. I drove 86 miles to the track and then 86 miles back home. Other than tossing the alternator belt during the run it performed great.

I would reaaallly like to say it’s an 11 second car, so I think I’m going to work to try and get it there. Then probably be happy with it.

But goes to show that if you don’t want to spend for the OD transmission you can still be fairly quick with a highway gear and still be able to put miles on the car.

[johnta1]

Congrats on the new ET best!

Other than subframe connectors I have zero traction control devices.

Being it's a 67 Bird, you don't have the original bars on the rear end?

[RocktimusPryme]

Originally Posted by johnta1

Congrats on the new ET best!



Being it's a 67 Bird, you don't have the original bars on the rear end?

No, I didnt have those anyway, mine was a lowly 326 car. That rear end is gone anyway. I swapped in an 8.5 from a 73 Nova. It has 30 spline moser axles and an Auburn limited slip I bought at a swap meet.

I did put clamps on the leaf springs, but thats the extent of my traction improvement devices.

[78w72]

congrats on the time.

as for traction control, before spending $$ for caltracs etc, try what cliff suggested to me, an adjustable pinion snubber. you can use the stock one & just use a ~2" piece of square tubing to drop it down to within about 3/4" of the top of the pumpkin. cliff explains that its does the same thing as bars out at the end of the axle only does it right in the center of where the pumpkin lifts up during launch. i tried one that could have been closer spaced & it made an improvement on my 2nd gen firebird that does low 11's with 3.23's. i plan to space it closer next time out & see how it works. im very traction limited also with very stiff front/rear springs & cheap summit drag shocks & can only launch off idle & roll into the throttle, if i hold against the converter at ~1500-1800rpm & stab the throttle the M/T drag radials go up in smoke & the run is lost.

also, are you using the tanks inc tank i recall you said you had? any fuel starvation issues show up? whats the rest of the motor/carb combo?

[RocktimusPryme]

Originally Posted by 78w72

congrats on the time.

as for traction control, before spending $$ for caltracs etc, try what cliff suggested to me, an adjustable pinion snubber. you can use the stock one & just use a ~2" piece of square tubing to drop it down to within about 3/4" of the top of the pumpkin. cliff explains that its does the same thing as bars out at the end of the axle only does it right in the center of where the pumpkin lifts up during launch. i tried one that could have been closer spaced & it made an improvement on my 2nd gen firebird that does low 11's with 3.23's. i plan to space it closer next time out & see how it works. im very traction limited also with very stiff front/rear springs & cheap summit drag shocks & can only launch off idle & roll into the throttle, if i hold against the converter at ~1500-1800rpm & stab the throttle the M/T drag radials go up in smoke & the run is lost.

also, are you using the tanks inc tank i recall you said you had? any fuel starvation issues show up? whats the rest of the motor/carb combo?

The In Tank pump and Tanks INC tank was a great purchase. My only complaint is that I feel like I have more fumes now. I cant detect any leaks, but maybe the AN line Im using as a return allows some of the small out. But yeah, everyone who told me 5 years ago to go electric was right. So much easier, much better way to go.

I have briefly looked at the pinion snubber idea. I need to look at it more in depth. It looks to me like on my car the OE snubber rubber piece just pushes into a slot. So if I wanted to make something that bolted in, Im going to be drilling holes. I also dont know how me not having the stock rear end is going to affect that plan.

I have nice Bilsteins in the front (great bang for the buck shock by the way)but I have cheap replacement KYBs in the back. So I might start with an adjustable rear shock. Ive also considered a spring replacement in the front this winter. If funds allow maybe I will just go for adjustable coil overs. Kill two birds with one stone.

I have the same cookie cutter 400 stroker that everyone does. Bathtub RP E heads with a little work. Flows like 305 CFM peak I think. Mild roller cam, I dont recall the exact specs but its smaller than an OF. Ported RPM intake and a custom Q jet from SMI. Th400 with a nice TSP converter.

[Formulajones]

Do you have a low gear set in the trans yet? If you're intent on keeping the 3.08's it'll go a long way in improving your 60 foot and ET.

[RocktimusPryme]

Originally Posted by Formulajones

Do you have a low gear set in the trans yet? If you're intent on keeping the 3.08's it'll go a long way in improving your 60 foot and ET.

No, honestly Ive kinda made up my mind that if Im not putting any money into the 400. If It goes Im going to step up to a 4l80e. It hurts to give up the money I have in the converter, but I think I would just be happier with the OD and a 3.55 rear gear.

Im hoping I can shave on 3 tenths while sticking the current setup.

[78w72]

thanks for the info. im considering the tanks inc tank myself but really trying to make the robbmc mech pump work for now, if i could see high 10's id be happy & leave it alone, the robbmc has been good for the times i posted but does have occasional starvation issues. your fumes could be related to long runs of braided hose, the standard stuff is supposed to have a limited lifespan, ive heard 5-7 years, but a friend of mine has feed & return braided lines in a low 10sec (low 9's on nos) car that have been in use for 10-12 years & they dont leak but the garage does smell of race gas. so i guess the lifespan is on a case by case basis.

your stock snubber should be bolted to the floor with 2 short bolts, but im not too familiar with 1st gen firebirds so could be wrong. if so, just do some measuring & drop it down to ~3/4" from the pumpkin. being a nova rear should still locate the pumpkin in the same general centered location, but take a look to see, its much cheaper than caltracs & worth a try.

the shocks i have are summit 3 way adjustable & seem to work as good as the cheaper adjustable drag shocks, 70/30, 50/50 & 90/10, i do softest setting in the front & middle setting on the rear, but with the PTFB stiff springs im not getting the full benefit of them.

good to hear the SMI carb is working ok for you, i used them on a friends stroker build i planned out for him a couple years ago & it runs great but never been to the track.

best of luck on finding 11's!

[Formulajones]

Originally Posted by RocktimusPryme

No, honestly Ive kinda made up my mind that if Im not putting any money into the 400. If It goes Im going to step up to a 4l80e. It hurts to give up the money I have in the converter, but I think I would just be happier with the OD and a 3.55 rear gear.

Im hoping I can shave on 3 tenths while sticking the current setup.

Oh that's right, we talked about that before.

I'm with the same line of thinking. I've played around with 3.08 gears and while it's fun and challenging while keeping the car highway friendly, I've always been much happier with more gear and an overdrive transmission.

I think everyone can relate to that, it's just a big expenditure.

I'm betting with more run time, tweaking things here and there, you'll find 3 tenths eventually. Just have to experiment and try things. Shucks even the weather can cost you more than 3 tenths, although I'd guess this time of year at Indy it should be pretty cool with decent DA numbers, and you're already close to sea level.
October was my favorite time of year to hit the tracks when I lived in Cincinnati, about the coolest weather you'll get before the tracks close for the season.

[RocktimusPryme]

Ive been very happy with the SMI carb. And Sean is good about taking phone calls to offer support if you have questions. The only consistent issue I have had, is if you have it hooked to full manifold and its cold, it will bog when you stomp on it. So just this week anticipating racing in sub 60* temps I switched it back to ported spark.

Ill look at the snubber again, but man it sure looks to me like the rubber just press fits into the floor.

And yeah Ive got no leaks, but I do have a stronger smell of vapor then I did with no return. The feed line is a pre bent 1/2 stainless line.

[1968GTO421]

No tips to offer but congrats on the new, great time and speed. Like others have said, tweak here and there and you'll reach 11's. Great going!

[RocktimusPryme]

https://www.heartbeatcitycamaro.com/...GM%23-3923564/

This is what my pinion snubber looks like.

[Formulajones]

Yeah many 1st gens are like that.

Unfortunately if you want to be sneaky and play with pinion snubbers like that, you can buy bolt on style snubbers but it will require some welding and fabrication work on your current bracket, then you can shim as desired, that is if you don't mind modifying your car that way. It's worth the effort if you really want the stealth appearance.

[mchell]

3 tenth improvement is very, very good. Good job!

Keep chipping at it!

I think You’re going to want a little bit more mph regardless of et to get your goal.......a little more mph would show you got the power to get your et goal and simply need to get the 60’ down to achieve it

As an example, Here’s a complete mess of a run with mine, but notice the mph vs et. Got in and out of it several times but still had enough grunt to mph close to normal with much lower et’s(11.0x)

[RocktimusPryme]

I thought the 88mph would be a few more MPH in the quarter but I guess I was incorrect about that. And that 88 is pretty consistent, I have a lot more 1/8 mile runs. I might have hit 89 once. So other than gearing, Im not sure what I can do to get more MPH out of it without actually adding power. Maybe play with a carb spacer. Not much room under the hood though.

[johnta1]

Your rear gear probably is holding that back?
Doesn't let the engine get into its power band for very long.
Might try leaving it in 2nd and wind a few more RPMs out of it?

[mchell]

Originally Posted by RocktimusPryme

I thought the 88mph would be a few more MPH in the quarter but I guess I was incorrect about that. And that 88 is pretty consistent, I have a lot more 1/8 mile runs. I might have hit 89 once. So other than gearing, Im not sure what I can do to get more MPH out of it without actually adding power. Maybe play with a carb spacer. Not much room under the hood though.

You said it....a little bit more power....timing, fuel, air, less weight??? All the above

Thinking you need 111-112 in the quarter...

[Formulajones]

Carb spacers can be huge if you have the room. There is always that pesky hood clearance issue though.

I agree you'll need a little more mph and or better 60 foot to hit your goal. 90-91 mph in the 1/8 would probably get you there. Doesn't sound like a lot but 2-3 mph in the 1/8 is a pretty big deal. That's a significant jump in HP or a significant drop in weight.

Could always do it old school style and remove the hood just to experiment with spacers and air cleaners, getting rid of the drop base deal and creating more space above the air horn at the same time is usually worth something.
Decades ago it wasn't uncommon for some of the guys I hung with to remove the hood in the pits so they could do that very thing, then bolt it back on for the drive home.

[RocktimusPryme]

Honestly I was thinking my general ineptitude would be leaving some meat. While it’s not my first rodeo, I’m also not exactly Warren Johnson. So I have doubts that I got every bit of it on that single run. Though I will admit conditions had to be pretty close to perfect. Would almost think I would luck into a tenth or two, just putting it all together on one run.

As I mentioned earlier, i think I could leave under more RPM. . Maybe both knock down the 60 and get into the power band earlier. I wish I remembered what the RPM was when I crossed the line. I know I’m usually about 5200 in the top of the 1/8 in second gear.

Funny thing is. Had I ran a 12.5, I would be happy and would leave it alone. But a 12.2.......that’s too close to be an 11 second car to just let lie...... My brain is dis functional.

[Formulajones]

You could always do what I've seen the ricers do all the time.

They roll into the pits and then continue to completely strip the car of all interior, with just a driver seat left. Their pit stall looks like a swap meet

Seriously though, keep at it. More laps. It's all about fun and experimenting.

How many more weeks are the tracks going to be open out there? I seem to remember around Holloween was about it around the Cincinnati area.