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Switching from a Turbo 350 to a 400?

Posted: Tue Oct 25, 2011 12:45 pm
by Roger Blackmore
Drag car only. 01 Formula Firebird. 408 LS1. 3470 race weight. Currently running a turbo 350 with a TCI trans break. 500 hp to the wheels. Spraying another 250. fixing to go to 300. This set up has been working well, but the clutches only lasted about 20 passes this go round.
Some people say it be be time to go to a 400. I'm looking for opinions from folks that have gone from a 350 to a 400. How did it effect your E.Ts. I am also thinking about going with a power glide. But don't know if that would wise at my current space weight.
Thanks in advance,
Roger.

Re: Switching from a Turbo 350 to a 400?

Posted: Tue Oct 25, 2011 7:34 pm
by BracketNova
I would say powerglide. They can be built pretty beefy for a reasonable amount.

Re: Switching from a Turbo 350 to a 400?

Posted: Wed Oct 26, 2011 6:22 am
by ytnova
Are you having to use a progressive with the nitrous and what size tire? If you are, or it has a small tire, I would go with a glide. Betcha a 400 would slow it down .05 over a 350, but if you are having to progress the nitrous with a 350, you can bring on more and do it a whole lot sooner with a glide, it will pick up.

Re: Switching from a Turbo 350 to a 400?

Posted: Wed Oct 26, 2011 9:03 am
by Roger Blackmore
28x10.5 ET Drag. I'm hitting it with 100% off the trans break with a 250 shot. It cuts high 1.3s to low 1.4s in the 60. We are tightening the converter up some while the transmission is out. Hopefully the 60s will get better.
So you are saying a power glide work in a 3470lb car?

Re: Switching from a Turbo 350 to a 400?

Posted: Wed Oct 26, 2011 10:07 am
by ytnova
My car is 3450 and it actually picked up with a glide, mostly because I can leave on more and ramp it in sooner and the fact it doesn't hit the tire so hard that I can now control it with the shock. If you car is dead hooking on 100%, a 400 might be a better solution for your current setup, but if you are planning on putting more power to it, you might start running into the same problems, a three speed is just too violent in first gear. In short, I don't feel as though the weight of the car is the issue with running a glide, I feel it is more about how much power it makes, how violent it hits the tire, or how traction limited the combo is, ie. narrow tire or radial.

Re: Switching from a Turbo 350 to a 400?

Posted: Thu Oct 27, 2011 9:25 am
by Roger Blackmore
ytnova wrote:My car is 3450 and it actually picked up with a glide, mostly because I can leave on more and ramp it in sooner and the fact it doesn't hit the tire so hard that I can now control it with the shock. If you car is dead hooking on 100%, a 400 might be a better solution for your current setup, but if you are planning on putting more power to it, you might start running into the same problems, a three speed is just too violent in first gear. In short, I don't feel as though the weight of the car is the issue with running a glide, I feel it is more about how much power it makes, how violent it hits the tire, or how traction limited the combo is, ie. narrow tire or radial.
Good info. Thanks. Would you share more about your combo, power, and ETs?

Re: Switching from a Turbo 350 to a 400?

Posted: Thu Oct 27, 2011 10:43 am
by ytnova
No secrets here, '72 nova, all steel except hood, 522 bbc, single dominator, single plate w/102 jet, 275 radials, 3.73 gear, 180 straigt cut glide, cal trac bars/springs. Went 5.47@133 with a 1.35 60ft in the 1/8 at SGMP a couple of weeks ago, leaving on 20% and rolling it out 1.5 seconds on the progressive. I have not been able to even that aggressive with it on the 1/4 mile track here in orlando, track prep has not been good, but it has been 8.77@160 with only 5.60's@128 in the 1/8th with roughly the same 60ft. There is more left in it, but the convertor needs to be adjusted since I have changed some things up, it was blowing through it. It was originally built for a th400 and 4.10 running mostly 1/4 mile with one kit, I tried putting in more jet, leaving on more, bringing it in sooner and also adding a second stage and all it did was turn the shift light on, it actually slowed down. I changed to the glide and the 3.73 to tame it down in the 60 foot, and it has responded well. I actually wouldn't mind trying to take some more gear out of it, but the convertor needs to be fixed first.
Every car is different, and I don't want you coming back here after you try a glide pissed, but you are point where a glide might really help your car, but it will be a pig on motor. I held out as long as I could, I wanted to stay with a 400, but after all the head scratching and frustrating outings, my car is definately alot better/faster with a glide and is so much easier to get down questionable tracks.

Re: Switching from a Turbo 350 to a 400?

Posted: Fri Oct 28, 2011 3:08 am
by wikd69
ytnova wrote:No secrets here, '72 nova, all steel except hood, 522 bbc, single dominator, single plate w/102 jet, 275 radials, 3.73 gear, 180 straigt cut glide, cal trac bars/springs. Went 5.47@133 with a 1.35 60ft in the 1/8 at SGMP a couple of weeks ago, leaving on 20% and rolling it out 1.5 seconds on the progressive. I have not been able to even that aggressive with it on the 1/4 mile track here in orlando, track prep has not been good, but it has been 8.77@160 with only 5.60's@128 in the 1/8th with roughly the same 60ft. There is more left in it, but the convertor needs to be adjusted since I have changed some things up, it was blowing through it. It was originally built for a th400 and 4.10 running mostly 1/4 mile with one kit, I tried putting in more jet, leaving on more, bringing it in sooner and also adding a second stage and all it did was turn the shift light on, it actually slowed down. I changed to the glide and the 3.73 to tame it down in the 60 foot, and it has responded well. I actually wouldn't mind trying to take some more gear out of it, but the convertor needs to be fixed first.
Every car is different, and I don't want you coming back here after you try a glide pissed, but you are point where a glide might really help your car, but it will be a pig on motor. I held out as long as I could, I wanted to stay with a 400, but after all the head scratching and frustrating outings, my car is definately alot better/faster with a glide and is so much easier to get down questionable tracks.
Geezo, that thing is quick !! I didn't realize you were running that fast, nice build and nice work !!!!

Re: Switching from a Turbo 350 to a 400?

Posted: Sat Oct 29, 2011 12:06 pm
by Roger Blackmore
ytnova wrote:No secrets here, '72 nova, all steel except hood, 522 bbc, single dominator, single plate w/102 jet, 275 radials, 3.73 gear, 180 straigt cut glide, cal trac bars/springs. Went 5.47@133 with a 1.35 60ft in the 1/8 at SGMP a couple of weeks ago, leaving on 20% and rolling it out 1.5 seconds on the progressive. I have not been able to even that aggressive with it on the 1/4 mile track here in orlando, track prep has not been good, but it has been 8.77@160 with only 5.60's@128 in the 1/8th with roughly the same 60ft. There is more left in it, but the convertor needs to be adjusted since I have changed some things up, it was blowing through it. It was originally built for a th400 and 4.10 running mostly 1/4 mile with one kit, I tried putting in more jet, leaving on more, bringing it in sooner and also adding a second stage and all it did was turn the shift light on, it actually slowed down. I changed to the glide and the 3.73 to tame it down in the 60 foot, and it has responded well. I actually wouldn't mind trying to take some more gear out of it, but the convertor needs to be fixed first.
Every car is different, and I don't want you coming back here after you try a glide pissed, but you are point where a glide might really help your car, but it will be a pig on motor. I held out as long as I could, I wanted to stay with a 400, but after all the head scratching and frustrating outings, my car is definately alot better/faster with a glide and is so much easier to get down questionable tracks.
Thanks for that input. Car is a beast. The thing that will keep me from changing to a power glide, is weight and a small block. Our race wt., I'm sure is close. But you are running a big block. So a lot more torque. Lol. I will limp along on the 350 for now. I need to get some more weight out of the car anyway. So maybe once that's done, the glide will be more doable.

Re: Switching from a Turbo 350 to a 400?

Posted: Mon Oct 31, 2011 6:12 pm
by 425 Olds
I went from a 400 to a 350 a few yrs ago and like the 350 in my car. I don't care for a glide at all and feel the 3 speeds will be quicker over a 2 speed. My car runs high 9.90s with a 1.30 sixty @ 3250#. Oh ya NA too.

Re: Switching from a Turbo 350 to a 400?

Posted: Mon Nov 21, 2011 11:27 am
by Blade
I would go to a glide as well. If I break another trans, then I will be switching over to a glide. But then again, I have already broke another bell housing due to having an internal balanced flywheel and having an external balanced motor. Gonna fix it one more time and then its off to a glide.