Orr89rocz's 1989 Camaro Iroc-z 5.7L

Looks good, did that rear end ever blow?

sweet Mr.MPH

that is a tight whore under there. looks nice

rear still holding strong. Gonna run it til it breaks i think. Transbrake would do it maybe :slight_smile:

4" makes 12.56 square inches and dual 2.5 makes 9.81… dual 3" makes 14.13. I’d go atleast dual 3 for your 700+whp powerplant. It could use the flow

Justin looks sick, bring it back down and well crack 700 with it

hell with 700, lets go for 800 :slight_smile:

Lol I’m ready for it

Just dont think i’ll have the time to get the turbo housings and then get to the dyno. This converter is too loose anyway, i need to get that replaced. Just not enough time left this year before i move to texas. If i can do atleast the turbo housings, i will try to get it down there again but its kinda doubtful.

Texasss? I’ll meet at the tx2k10 meet lol well either way hope everything works out and
goodluck man

justin what size core is that for yoru IC? also got link to it? whats your IAT rise?

http://www.treadstoneperformance.com/product.phtml?p=312&cat_key=63&prodname=TRTTC+Twin+Turbo+Intercooler%2C+Chevy%2C+Corvette%2C+GM%2C+Viper

Core Size, 25" X 9" X 3.5"

I dont know what my IAT rise is, as i dont believe my sensor is picking up the right air temps. It never got above 135 at the track but at the dyno it saw 150 on the final pulls but doesnt change much at all during the entire pull so i dont think its working

450 one you got? thinking i want a 4" core one if not i might just get some off ebay and tig them together

what ARs on those 60s? mine are 68 thinking of upgrading

Yep i got the 450 dollar one, it was biggest one they had.

My 60’s have .68’s and I AM upgrading to .96’s :slight_smile: I think these are TOOOO small for a 401, i should go with a 64mm on a .96 A/R, but definately going to run .96 a/r

when was it choking up? id like to carry to 6200 with the 62s

your compressor discharge 2.5" ? when are yours full spool? these will end up on 382

did you ever try plotting your setup on a turbine map to see if your heading in the right direction? (not that arent :stuck_out_tongue: )

Well there are no maps for these master powers but I compared them to a similar wheel size garrett and I am in the right range for the power numbers I want. Granted the garretts probably use more efficient/higher flowing wheels even tho they are the same size.

I shall try the .96 housings and if this doesnt change my top end, then I may have a problem with the cam/valvetrain but I dont believe thats the issue.

i dont see why these turbos cant support 400whp a piece… i saw 690whp with a crap rich tune with issues with backpressure I think and a converter that isnt working right. 800whp is where i want to be ultimately. I trap 141 with 650whp. 800 puts me near 150 i think, probably higher and thats close to an 8 second car :slight_smile:

when was it choking up? id like to carry to 6200 with the 62s

your compressor discharge 2.5" ? when are yours full spool? these will end up on 382

You seen how my converter flashed sooo high. Its way too loose so i have no idea what “rpm” full spool is, but just look at the dyno vid again and think back to that day… Full throttle hit and it was spooled in a second since the converter flashed and he did start the run at a lower mph speed so the initial rpm was low. If i had a manual, i’d guess full spool would be around 3000 rpm or so which is where i wanted it.

Do have 2.5" discharge. BUT i do have 3" single inlet. I MAY need to change that to a larger pipe, that may be a cause of my backpressure. Working the 60mm wheels too hard and having to pump through that small 3" pipe. More than likely I’ll replace the inlet pipe and throttlebody before i do the housings but not sure. Maybe do it all at the same time.

Either way the cam should go to 5800 rpm. Similar cam in a 369 sbc pulled to 6500 rpm peak hp. My 401 will swallow that cam and should peak 5800. I think i saw peak hp at 5200-5300 rpm and it carried abit then fell off. If its backpressure issues i can see why it didnt pull higher. Hope to get turbine housings and with my dual 3" exhaust now, hope to see higher rpm.

But then again not sure how accurate the dyno numbers/rpms are. Converter may have hid true peak rpm, but tq/hp cross on the graph is 5252 rpm and thats where my peak was. Hard to say sooo many variables. So much needs replaced

have you measured your back pressure?

give you an example of how that backpressure will kill a cam’s range. the ls6 cam which seems to be very popular pulls na till about 6200 but in every boost setup ive seen ti starts to choke at 5500 and drops badly at 5800. sorta what yours is doing. more duration would allow you to pull much higher.

im kicking idea of going from 2.5 off the discharge to 3" charge pipes instantly and then of course going 4" to the tb. this should create less IATs and allow the spool range carry little further. i do plan to do dual 3" with these turbos i know i can fit 4" dp on the one side but doubt i can do that on driverside, however i may even do 3.5 but will see. going to see if i can step up to a large AR. should be interesting with a 3200 stall and 410s.

heres a thought if you have time to do this. get another boost guage mount it in the IC before the core then take reading at intake for other reference. see how much drop you are seeing. if you see more then i think 2psi drop that can also be causing your power range loss. some say your dual 3 into single 4 is causing you issues but then others say its fine. changing it out cant hurt and can only help. simple solution would of been toss cut outs on the DPs.

Havent measured backpressure, but thinking of tearing things down to weld in a bung for it.

For a 382 pulling that high i dont think you can go wrong with bigger a/r’s. If it spools at like 4500 then you still have a wide powerband from 4500-6200+ rpm

typically a good setup gives you 3k worth of power band. thus why i was thinking 3200stall and shift around 63-6400.

something to think about your setup is working and since you dropped gear use it to your advantage. use the powerband you have now you change power bands then you might want to reconsider gear