Bigtoyz

iTrader: (2)

I was thinking of doing LT1 dual rear PT6262 Precision turbo's A/R .84, wanted to get 600-700 for the street. And want to get the car setup for track and what to see around 1000 give or take a few on a 383 with 60E with 3200 stall 3.23 gears at around the 3900lb mark. 6500 redline

Or should I do pair of PT6266 A/R of .81?

They are both rated for little over 700 hp 705/735 but I drive it alot in the summer time so streetablity is big for me, however; I want to get into drag racing with it in time. One person mentioned the PT6262 but in A/R .68 with the cam and heads it does spin to 6500 pretty easy.

I have 187cc TPIS/AFR heads on it now....realizing that I might have to goto a bigger head but want to try it out before I switch them out.

54cc chambers

Lift In. Ex.
.100 66 56
.200 138 103
.300 204 144
.400 247 171
.500 272 185
.600 275 197

The intake flows alright for the 187 cc intake side. I was thinking with the 197 exhaust side is a little on the low side. That it should be able to spool the turbo's pretty good to keep up the velocity. Or am I wrong in thinking that, from what I read on rear mounted turbos........... the turbo will be the bottleneck of the exhaust system. Or would it be better to goto headers also?

postal14

iTrader: (8)

The better a engine flows the better it will spool turbos, the better an engine flows the less boost you will need to make a certain amount of HP. Knowing how much HP your engine would make naturally aspirated, and how good of an Intercooler set up your going to run are two of the main factors when sizing turbos from scratch.

If you like math and science you can get into the stuff above and beyond. If you dont you will need feed back from peeps running a vary similar set up to what you want to run. Make sure its LT1 feed back to be more accurate.

Bigtoyz

iTrader: (2)

Last time I tried to get it dyno tuned I was 386/358 rwhp and tq at 3600 rpm had bad opti at that point in time. Should get it back here soon I hope anyways.

But gonna put one of those Burkhart front bumper supports in. So I can get a intercooler for the size I need. But was thinking of 2 into 1 cooler. And also doing a meth kit also. I dont know what it really flows right now. Hopefully I can get a few answers from my tuner.

But from stock to what I have right now is a massive jump in air flow. I had stock motor with 8.5:1 fordged pistons and was getting 12 psi out of 15 psi pullies. After I rebuilt it got a whooping 3-4 psi out of same supercharger system, so I took it off. So I guess I'll have to get into the math aspect of this I guess to find out flow info and wait to hear from tuner. But if anyone has anything out there like it let me know what you got and what your getting for power.......greatly appreciated!

I'm also thinking I might go with 1.7 rockers on the exhaust side also. The heads will allow it and I definetly have the valve to piston clearance to do it.

postal14

iTrader: (8)

OK... Some guys want to know what works, they called a shop or a vendor, followed what a buddy did or a fellow board member ect.. If it did what they wanted it to do then thats all they care about, IT WORKS, and they are happy. That argument is 100% valid.

But... Some guys want to know why it worked, and they research into it. They start getting more and more self educated on it and actually enjoy it. Then you start finding equations and calculations.... that stuff is WAY funner than sudoku

Give 20 of my buddies some equations and calculations you would get maybe 2 of them to muddle thru it. Not a damn one of them would actually want to do it much less think it was fun. So I am the odd ball that actually likes that stuff. If you think you may be an odd ball egg head like me, Start here if you find yourself wanting to read more then you may truly be an egg head too:

http://www.turbobygarrett.com/turbob...rbo_tech_basic

postal14

iTrader: (8)

You are tapping into an area that is hard to get guys to understand. Its actually very simple. Boost isnt a direct correlation to HP. Boost is when your forced induction is trying to pump more air into an engine than what the engine wants to flow thru it. Since the turbo or supercharger is trying to pump more air in that whats being used the air starts backing up in the intake manifold and the pressure in the intake manifold rises. If your motor can flow as much or more than what your supercharger can pump then you wont build any boost at all. In your scenario of dropping from 12 psi down to 4 psi some guys would go buy a different pulley to try to get boost back up. I would tell them to go buy a larger supercharger and hold the f*ck on!

Bigtoyz

iTrader: (2)

I had thought of that also. I would have to go from 7.5 to 8.5 crank pulley. But the difference in rpms I'm really not gonna get enough out of it. I'm gonna gain 12k rpm more out of the supercharger. I maybe get another 1 maybe 2 more psi out of it. I wanna get more out of the motor than that.

I have it forsale with sale pending. If it doenst go I'll put it back on till i get the new turbo's or put it in my 4.3 S10 now that would be fun there!

postal14

iTrader: (8)

Oops... I didnt read your sig. When I saw the 12 to 4 I got it stuck in my head that you had a positive displacement sc. I just now seen that you have a procharger. The procharger might respond decent to a pulley change. Thats a centrifugal compressor and centrifugal's usually like rpms if youre not spinning them to fast to start with.

If you put your sc back on look stupid close at anything on the suction side. All pumps "PUSH" they push whats in them out. This creates a low pressure area on the inlet side and something else fills them back up, atmospheric pressure, gravity, a booster pump ect. In your case its atmospheric pressure pushing air back into your supercharger. You want to make it as easy as possible for mother nature to fill your super charger up. If you rely on your supercharger "Suck" the air in then you dont understand whats really going on. If mother nature isnt filling your supercharger all the way up then your supercharger isnt pumping the full amount of air for how fast it is spinning. A 1000 hp supercharger getting 500hp worth of air into it is only going to push 500 hp worth of air out of it. If the motor is wanting to flow 500 hp of air or more on its own then guess what your boost will be.

Bigtoyz

iTrader: (2)

Yeah I was thinking the samething as you were......I want to clean it up a bit and see what I can get rid of.

I'm even thinking of going SD mode and get the maf out of there also. I even removed the air cleaner also and that didnt change anything either. I have an air cleaner that can be cleaned. I did have a K&N but I didnt like it. I tested the oil a couple of times and the silicone levels were to high for my liking. I dont live on gravel road anymore. But I spent some big money for a foam cleanable filter that flows good. And the oil tests came back way cleaner.

And probably goto a blow off valve vs the bypass valve you get with it that recycles it back into the system.

I loved the Procharger units.......I thought going with a twin turbo I might get into it a little cheaper. Was looking to get F1c and just kind of sick of dealing with all that compact crap in there. And added bonus of not having side tension from the belt. And I'll really have hook up issues at that power level off the line. And turbos arent as torquie off the line as the procharger are, but already enough torque off the line with the 383 stroker. And was going to do the eboost controller and set it hp by gear. I know there is a gear unit now for procharger headunits but adds 3k to the tag.

I was gonna do the tubo system myself, so I was thinking 2k for turbos and another 2.5k for IC and tubing for the intake side tubing, blow off valves and electric oil pump and etc. F1c is right around 5500 and still all new tubing and IC, and mounting bracket.

I'm seeing more benifets for the turbo system vs the Procharger.

Bigtoyz

iTrader: (2)

I know you can empty the intake side out......had a time when the K&N didnt get cleaned in time and it litterally went into vacum just off the line. So I have seen a supercharger system act naturally asperated. So I know what you are talking about.

Bigtoyz

iTrader: (2)

Well I finally got a solid answer I was looking for......... Precision 64/66's. They have better driviablity than a 6262 for some odd reason. They have better flow than 6262 in the midrange and spool just as quick. Now just to decide where to put them....up front, they mentioned back by bellhousing, or in the rear. In the rear there is a real issue of pumps going out for what they need to do for a daily driver. He said they replace 3 of them on same car within 2 years and now they found one that is holding.

In the front I'll probably have to do the LSx ign conversion cause the heat might cause issues with the msd opti. Which I was not really looking forward to doing.

postal14

iTrader: (8)

This thing here is crazy, click on link and then the graph in the middle.

http://www.turbodriven.com/en/perfor.../matchbot.aspx

Bigtoyz

iTrader: (2)

oh man for the info.........

postal14

iTrader: (8)

Hehe, there is like 1 hour worth of tutorial videos to use their turbo match maker! Its cool as **** tho I found it the other day and have played with that damn thing for a few hours. Cool thing is you can get some immediate answere to some stuff. Like screw around with :
...IC efficiency and see effect on hp
...turbine housings and wheels and see effect on back pressure
... hell most every number on there will effect HP, or back pressure, or both.

One thing I didnt like was it seemed like if you where doing something that mainly effected back pressure, Like a larger turbine wheel or housing, that it did not recalculate hp... that just does not seem right to me.

Also their compressor maps to pick from are a little hard to identify which exact s400 turbo they matched up with but is pretty specific for the little turbos.

Bigtoyz

iTrader: (2)

Yeah back to the whole map thing again where I get lost. I'm gonna have to try and figure it out again. I'll look for those help video's maybe that will clear some of it up for me. But yeah that really would be helpful tool to figure out things. Thanks for linking that for me......

postal14

iTrader: (8)

The tutorial videos are clickable links at the bottom of that same page where you are plugging your numbers in. I really like the back pressure stuff because I could never find any info on calculating that. I have been all over compressor side calcs and compressor maps well before there was an internet. Maybe the turbine side was way to complicated or something because I never found any info at all about it. On that program on Borg's site once you get all your numbers in you then use the plus and minus buttons to get all 6 of your plot points onto the same turbine wheel / housing line. Then you look back at the calculated values and it will show you the exhaust manifold pressure, delta p across the motor ect.

tt383lt1

iTrader: (3)

i would call percsion turbos and ask the tech for the right turbos. i called turbonectics and they set me up with the pair of blowers i got now and the spool at about 2800 rpm and full spool by 3300 to 3500. but thats with them under the hood. not in the back. if i was you i would try to get them as close to the engine as possible.

Bigtoyz

iTrader: (2)

hey 383 what kind of power are you making? Just curious.

The new tuner guy I have been talking to has a couple pairs of the 6466 on a couple cars simulair to mine. And feels like it would be a good match for me. But here in next couple of weeks I'm gonna go down and he is gonna take a couple of hours and go through exactlly what I want out of the car and do with it. He wants me to bring down my engine specs so he can look at them more closely. So I can get a rough idea what it is gonna cost to do this system. But it looks like I'm gonna have to find a set of shorty headers that will work for me to keep them in the front. I wanna keep my ac so have to find away to work around that. And I might as well start to piece together a LSx 24x ign system now also. Cause that is what it is looking like I might have to do.

And I brought up the concern of my heads.....and he was saying the samething that I was coming to do is........use the heads I have now and
see what they do......he said you might be surprised as to what they will do in the system like this. He is familiar with the TPIS/AFR heads and said they are not a bad head. But anyways try them and not getting what we need then change them out with a set of bigger heads.

tt383lt1

iTrader: (3)

im still getting the tune done. i went 2 times already (first was drivibility, secound was spring presure, third is full out boost) and( we had to start from scratch the pcm was locked) but at 10.5 psi it put down on tpis hub dyno 720tq @2700 rpm and 470 hp@ 4500 and flatlined. tpis said its my converter. and alot of people said its there dyno. but i have to wait to get another $500 to finish the tune to 20 psi then i will know for sure. and taking it to a diffrent dyno after.

but on the street it pulls hard all the way to 7200 rpm. so it cant be the converter. it doesnt slip on the street. but they did a nice job on the tune so far so im no mad at them. i just dont think there dyno is all that good.

but with the little leg i do have im not mad at all. it spools quick enough for me to be happy. and turbonectics set my turbos up for my engine

Bigtoyz

iTrader: (2)

Oh that is right your up in the cities. You have a pretty good starting point I would say......alot of tq or is it suppose to be 420 tq?

But wow you have to come up with another 500? Crap that is what I paid for my whole tune drivabilty and dyno tune.

I would go talk to DRM if I was you.....I know he does good work.

tt383lt1

iTrader: (3)

no thats right 720tq. and 470hp but i already have $1200 into the tune alone. and the reason why it costed so much is the 2000cc injectors, 3 bar map, e85, 24x conversion, and the oil got hot after a hour of running so we had to cool it down for 15 to 20 min every hour and we had to start from scratch no data what so ever to start with so it was just time consuming. and they charge 270 for the first hour and 100 for every hour after. the main reason i went with tpis is i had hitech do it last time and the tune sucked. this time it is dead on.

and drm is about 3 to 4 hours from me im close to tpis or full blow in applevalley.

if you can get your new engine tuned for $500 jump on that. i wish it only cost me that. the last time i was up at tpis i bought over 200lb of ice and 5 to 6 hours of tunning

when my engine was NA it cost $550 for tune/dyno.