any one know about Turbos

[HotrodDaddy43]

So I have decided to turbo my 350 in my van I have never done a turbo before I've messed with a blow thru Vortech super charger and played with the laughing gas and now I want to do a turbo. I have a few question. what will I need to control the trans as im going to upgrade the injection to a Holley commander 950 system (since i have one already) im thinking the best place for it will be under the van. I've seen where vettes and what not have put them to the rear im guessing for room as well as cooling the intake charge. if doing this how would you combat the lag? anyway any help or input is always be closely listened to. Danny

[LiftedAWDAstro]

Mr Roboto is the guy with lots of turbo knowledge. 97turboastro did a california customs turbo kit in his van and it performed awesome! I do know STS Turbo makes the kits that go under vehicles.

[1Gary]

Yeah-it might be worth a PM to Mr_Roboto because he might have the parts to do the job.He posted he is abandoning his project but I know he had turbo's for it.

[Mr_Roboto]

Blow through Vortech? If you want to keep the carb than that's fine, I'd check theturboforums.com formerly turbomustangs.com as they have a huge section devoted to it. Brent Davis is da man, he has done some nuts stuff with carbed turbos. If you are going to use a Commander 950, I would talk to Turbo355 as his TA ran low 9s with a JY 350 (no joke) and a C950. He tuned/tweaked it like crazy to do that however. It was on a pair of Buick Grand National turbos and a 75 shot of spray at 22 PSI.

How I was going to do mine was on the passenger side above the engine, I have a home brew A/C delete box too. It was going to be a Detroit Diesel turbo, and I was going to notch below the heater box for a 5" down pipe. Probably overkill, but it's what the outlet size is. That being said, I would definitely consider a different trans than a 4L60E/700R4. TH400 or 4L80E. If you go with the 80, you would need a controller. I'm working on/at putting one in my van right now but it's a long time away. What are you making roughly power wise right now, and where do you want to be power wise? Static compression? Camshaft?

[youtube]http://www.youtube.com/watch?v=tqsbqXKLXN0[/youtube]

[doyoulikeithere]

Nice Vid. I bet the AWD helps him win almost as much as the turbo, eh?

[Mr_Roboto]

It probably does, but if it had slicks or DOT radials it'd probably do as well 60 foot wise and be significantly lighter/less power hungry. If I remember correctly that's a low 12s/high 11s vehicle however so it's pretty stout as-is. The big thing about it was the end, where they show the underhood shot and you can see how they placed their turbo.

[HotrodDaddy43]

I like that " we ran out of things to turbo" classic. lol

My engine is a stock rebuilt 1994 chevy truck 350. I'm wanting to do Alm heads, roller camshaft and turbo. and I want to make it live. so like 15 lbs boost max.

[Mr_Roboto]

Don't forget boost is a measure of restriction, it doesn't tell you what you need to know about the turbo setup it self. To really "size" a turbo properly you need to know roughly how much power you'd make without the turbo and how much power you want with the turbo. Lets take my 305, if I ever got the darn thing running for a sustained period of time lets say my mods net 270hp. Probably on the generous side but besides the point regardless. My ultimate goal is going to be 475hp. Because of this, I know that I know I'm going to need

(475/270-1)*14.7

Breaking this down some:

475/270 is the amount of HP over n/A you're producing. This comes out to ~1.76

1.76-1=.76 The reason we do this is the .76 is the amount over atmospheric pressure we would need to achieve this HP goal

.76*14.7=11.17 PSI. The reason we multiply by 14.7 is that is atmospheric pressure.

Taking this further, we can say that for every HP it takes 9 lb/min of air to produce (there's a # floating around for this, but don't ask me what it is. 9 would get you in the ball park.

Taking 475/9 we get 52.7 lb/min of air. We can take the two lines and cross them on a compressor map:



Taking this compressor map, We would go to 1.76 (the maps are based on absolute pressure) and then we would see where the point crosses at 53 lb/min. No we won't get super precision from this. However, we will get an idea of where our turbo's at on the map. In this case a T70 is at the second island instead of the middle most one. Not a match I'd complain about though, overall at peak HP this would likely be a good fit. The other question we would want to look at is making a few points at lower power levels (spool up, lower RPM) and seeing where our line comes to. If we're fully spooled the line will be horizontal, if we are spooling the plot would run upwards and to the left diagonally.

I hope this gives you a few basics to understand a bit more about turbocharging. You really need to know what your engine's going to be if you're doing this well. For what it sounds like you want, I wouldn't be afraid of say a Master Power T70 through something as big as an S400. My optimal would likely be a T76 as it will make good power and packaging isn't going to kill you like the S400 or another Detroit Diesel sized turbo will.

[HotrodDaddy43]

I'm guessing since my engine is a stock 1994 truck engine its right at 200hp. I am think about 20 % or so going to a decent set of alm heads so 240 -250 with the heads on. I would like to see 400-450hp with the turbo. More would be ok but like I said I want it to live. could the stock tbi system be made to support that? just thinking if so it would solve the transmission control problem if i went to the cm950 system.

[Mr_Roboto]

I'd find a used TPI intake and a set of Lightning injectors plus a Walbro 255 if I wanted EFI. The C950 will work with it. It would work well for that sort of power IMO, you shouldn't need any fancy heads really to get to that kind of power level. Possibly not even a cam shaft, but I'd really throw one in with a good set of valve springs. Even a stock TPI cam would net you 25hp over a stock TBI one, and LT1 cam with the pin pushed in even a little more. Port out the TPI intake some, and you're looking at near 250hp (stock for stock, the TPI heads don't actually flow more than a couple CFM higher than the TBI ones) so then you're only looking at running say 7-10 PSI on that engine to get to 400.