Twin Turbo 400 Buildup- '89 Iroc-Z
#501
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
ive found that the water water stuff doesnt work all that great. But the DEI stuff isnt really an additive like the waterwetter. I might try it and see.
I got a stefs fabrication dropped air cleaner. Its a 1.625" drop but the top of the air cleaner is buldged uupwards http://www.summitracing.com/parts/STF-72200/ and im running it with a 3" filter due to the height im worried about. well see, my Application needed a 4" filter due to the insane air a 521 moves at 6000rpms
I got a stefs fabrication dropped air cleaner. Its a 1.625" drop but the top of the air cleaner is buldged uupwards http://www.summitracing.com/parts/STF-72200/ and im running it with a 3" filter due to the height im worried about. well see, my Application needed a 4" filter due to the insane air a 521 moves at 6000rpms
#503
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Car: 91 rs
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
It seems to work better when added to straight water.
My $450 harwood 4" flew off on the last tow. Cracked it and rounded the edges. Pretty much junk since there isn't any point in painting it. It'll just crack up. Oh well, I really want a hinged hood anyway.
My $450 harwood 4" flew off on the last tow. Cracked it and rounded the edges. Pretty much junk since there isn't any point in painting it. It'll just crack up. Oh well, I really want a hinged hood anyway.
#504
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Car: 85 Berlinetta
Engine: 408 SBC with a S-480 Turbo
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Axle/Gears: 3:23 28.5" tire
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Those twin 70mm turbos are gonna move SOOOO much more air than the 60's! It's gonna come on like a 2-stroke into power band!
#505
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Just alittle update on this car since its been along time since its seen some action. I have the new T70's on the car up and running. Been working on the new tune and really dialing it all back in since I basically smoothed out the VE tables and started working with that new map. I had to change a good bit of it but its coming alive.
I also worked the free revs and cold start..finally got it cold starting just fine on first attempt. Idle is pretty good but gets abit picky when both fans are on and the motor is very hot. Heatsoaking the wires may be causing some of the problems...like voltage drop across the lines or something. Need to work on the battery compensation tables.
I been driving it this past month on a few days since it rained most of the time. I was up in PA for work this past month it seems. Unfortunately it rained on every scheduled track day so no racing yet for me but the car is ready.
Overheating is no issue now with dual fans from the LS1 car. I fixed my oil leaks, turned out it was a lose oil pan bolt!! I cant believe it.
No more blow by and popping the dipstick, i guess the loose manifold bolts were the problem. Now they are snug and car is fine.
C5 brakes are feeling better with mileage put on them. Still look small, i should get C6 Z06's or CTS-V 14" stuff
I will eventually clean up these hood cutouts for the turbos but just havent gotten around to it.
Also made a cover plate for the old air box on top the bumper cover... cleans up the look abit
So far I started at about 8 psi and tuned that abit, then moved to 10 then to about 12, then accidently abit over 18psi and just now backed down to 14 or so. Running abit rich but safe. Have some timing retard that I believe is either false or I was spinning tire...and I think it was spinning tire
I also worked the free revs and cold start..finally got it cold starting just fine on first attempt. Idle is pretty good but gets abit picky when both fans are on and the motor is very hot. Heatsoaking the wires may be causing some of the problems...like voltage drop across the lines or something. Need to work on the battery compensation tables.
I been driving it this past month on a few days since it rained most of the time. I was up in PA for work this past month it seems. Unfortunately it rained on every scheduled track day so no racing yet for me but the car is ready.
Overheating is no issue now with dual fans from the LS1 car. I fixed my oil leaks, turned out it was a lose oil pan bolt!! I cant believe it.
No more blow by and popping the dipstick, i guess the loose manifold bolts were the problem. Now they are snug and car is fine.
C5 brakes are feeling better with mileage put on them. Still look small, i should get C6 Z06's or CTS-V 14" stuff
I will eventually clean up these hood cutouts for the turbos but just havent gotten around to it.
Also made a cover plate for the old air box on top the bumper cover... cleans up the look abit
So far I started at about 8 psi and tuned that abit, then moved to 10 then to about 12, then accidently abit over 18psi and just now backed down to 14 or so. Running abit rich but safe. Have some timing retard that I believe is either false or I was spinning tire...and I think it was spinning tire
#507
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
It dips but climbs back up and stays in the low mid 13's. I notice its going lean at idle after driving for awhile and getting hot/heatsoaked. When its cold/cool and driving for few minutes, its fine. So it could be just temperature offsets with fueling tables but I dont see anything in the code that would offset my fueling. I think the temporary voltage drop starts the surging since it either overly richens or leans out alot and the motor cant recover right away.
No big deal, I just need more time to figure it out and tune it out. I wanted to idle at 800 rpm but when hot it just wasnt happy. Moving to 900 rpm makes it abit better.
No big deal, I just need more time to figure it out and tune it out. I wanted to idle at 800 rpm but when hot it just wasnt happy. Moving to 900 rpm makes it abit better.
#509
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Wow looks good! I got a question on the brakes. Are those the 13" vette rotors? I just purchased a 13" kit from BAER that is from the 88 and up zr1. Just wondering bc I got the biggest to fit under my 17" rims. You have bigger rims... I would look into the kit from ed that has the new camaro SS 14" rotors and brembo calipers. I like the caddy brakes tho too.
#510
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
My GTA did the same thing when it was running the turbo, as the alternator would get too hot from the underhood temps at idle during standstill (mainly during the warmer weather, when it was cold out there wasn't a problem), and when both fans kicked on the injectors immediately lost voltage causing O2 correction a tad beyond it's threshold. I did two things to fix my condition, as I ran a higher amp alternator and I also tuned for an Open Loop idle. It did in fact fix the problem....
Brakes are C5 Z06 calipers and C5 brakes which are like 12.8" i believe..basically 13". They seem to stop good but not as good as i hoped. Still need some break in time and I think i have a small leak in my vacuum booster but it works ok enough for me.
I actually stopped hard enough that the car shut off on me...not sure what that was but I had less than 1/4 tank in a baffle-less tank so it may have just starved out
#511
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Nice!
I think I zeroed out my bpw vs voltage but have to check, been a while now since looking in tunerpro
I think I zeroed out my bpw vs voltage but have to check, been a while now since looking in tunerpro
#513
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Car: A lot and 86' Z28 and 88' Camaro
Engine: 305, 383 and 565
Transmission: 700R4, th400 and 4L80
Axle/Gears: Frd 8.8 /3.27 and S60
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Man things are looking good Orr. Hope you can get to the track soon, we would like to see what she'll do. I'll leave the turbo stuff for you guys (too much work for me right now) and stick to the bottle lol. That looks good though.
#514
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Car: '85 TA
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
What is your timing at idle?
Are you able to datalog the idle and see what is happening when the fans turn on? If so, find the rpm/kpa in the table where it goes to when fans turn on and increase the fueling in that area.
#515
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
I have always targeted stoich as idle unless the motor could handle otherwise. Right now I have about 14.0 to 1 idle but when hot it creeps up to 16.0. 25 deg timing locked at idle cells. Idles great.
Both fans on when motor is cool, no problems. Only when they are both on when hot, the motor starts to hunt for idle. Its got to be too lean for its liking. If I had idle up to 1000 it may not have an issue but I dont want it that high because this motor shouldnt be higher than 850.
Both fans on when motor is cool, no problems. Only when they are both on when hot, the motor starts to hunt for idle. Its got to be too lean for its liking. If I had idle up to 1000 it may not have an issue but I dont want it that high because this motor shouldnt be higher than 850.
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
My engine is always in closed loop from idle to WOT, which allows the engine to compensate for any condition. Can you change yours to be in closed loop all the time or at least for idle? If not, do you have a coolant temperature fuel enrichment table that can add fuel at the temp rises? If you can't do either, then you will probably have to run richer at cold idle, so that hot idle isn't as lean.
#519
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
In code $59 there is a targeted air fuel ratio table that I believe is used with the closed loop wideband o2. Not exactly sure it does anything in open loop mode but it may.
I just tune the VE tables to get the air fuel ratio I want under the load condition i'm at.
I just tune the VE tables to get the air fuel ratio I want under the load condition i'm at.
#520
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Looks amazing under the hood Orr! Time to put up some new youtube video - now get to it!
What kind of money did the LS1 fan setup cost you? Seems like they move a lot more air than the open style of the third gen. I need to come across a set for mine so I can try and put my fog lights back in place.
What kind of money did the LS1 fan setup cost you? Seems like they move a lot more air than the open style of the third gen. I need to come across a set for mine so I can try and put my fog lights back in place.
#521
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Both fans on when motor is cool, no problems. Only when they are both on when hot, the motor starts to hunt for idle. Its got to be too lean for its liking. If I had idle up to 1000 it may not have an issue but I dont want it that high because this motor shouldnt be higher than 850.
Sometimes engines are like women, they want what they want even if it doesn't make any sense...
#522
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Car: A lot and 86' Z28 and 88' Camaro
Engine: 305, 383 and 565
Transmission: 700R4, th400 and 4L80
Axle/Gears: Frd 8.8 /3.27 and S60
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Had that same problem with a customers car. Tried tunning it out with fuel, spark and tables but that didn't work. Raising the idle worked but didn't want the idle at 950 rpms. Found out it was the fans drawing too much power from the computer when they were on at idle which reduced the power to the injector driver. Had a 140 amper on it but fixed the problem by installing a overdrive pully on the alternator for$15. Now in the heat of summer with the ac on and the fans running at idle it sits dead smooth.
#523
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Hmm interesting Big Dog. My car does this too, only when it's really hot. Especially if heat-soaked after being parked about 30-45 mins. It surges and goes between lean and rich. I will have to take a better look at battery voltage and fan operation during this behaviour.
#524
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Car: A lot and 86' Z28 and 88' Camaro
Engine: 305, 383 and 565
Transmission: 700R4, th400 and 4L80
Axle/Gears: Frd 8.8 /3.27 and S60
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Yup that's when his car would do it. The problem got worse as we turned up his fuel press to make up for maxed out injectors. I think as the ability to control the injectors went down due to heat and voltage drop from the fans it caused the afr to change which caused the motor rpm to change which made the computer try to keep the same idle rpm by making adjustments which causes the idle to go up then the voltage picks up which causes the computer to lower the rpm and so on. I had the problem in open loop and closed loop which made me look at other things. I sat back and looked at the car for a while and thats when I tried running the car with a battery charger hooked up. With the charger in didn't do it but take the charger off then it's up and down again. Although the voltage gauge read 13+ volts the computers voltage dropped when the fans came on in idle. It also did it when I held the power window buttons down with the headlights on, that's when I was sure it was the lack of amps.
#525
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
What kind of money did the LS1 fan setup cost you? Seems like they move a lot more air than the open style of the third gen. I need to come across a set for mine so I can try and put my fog lights back in place.
Had that same problem with a customers car. Tried tunning it out with fuel, spark and tables but that didn't work. Raising the idle worked but didn't want the idle at 950 rpms. Found out it was the fans drawing too much power from the computer when they were on at idle which reduced the power to the injector driver. Had a 140 amper on it but fixed the problem by installing a overdrive pully on the alternator for$15. Now in the heat of summer with the ac on and the fans running at idle it sits dead smooth.
Had same problem with underdrive crank pulley on my 383 but soon as I swapped to smaller alternator pulley, the problem went away.
Now i never thought about the fans drawing power from the ECM. Thats a different issue I never tested or even looked at.
#526
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
What about settig up deducted relays for the fan directly off the batt to minimize voltage drop? Or you could setup a dual battery setup which will kill your weight. I've gotten much less voltage drop by making my own dedicated harnesses for fuel pump and fans as well as relays for my HIDs. Increasing the wire thickness also seems to help. Did you upgrade the batt cables and grounds?
#527
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Car: A lot and 86' Z28 and 88' Camaro
Engine: 305, 383 and 565
Transmission: 700R4, th400 and 4L80
Axle/Gears: Frd 8.8 /3.27 and S60
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Man you would be surprised. More than likely its the litttle things that cause big problems. I bet its the lower voltage at idle that is the culprit. Ben there.
#528
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
What about settig up deducted relays for the fan directly off the batt to minimize voltage drop? Or you could setup a dual battery setup which will kill your weight. I've gotten much less voltage drop by making my own dedicated harnesses for fuel pump and fans as well as relays for my HIDs. Increasing the wire thickness also seems to help. Did you upgrade the batt cables and grounds?
I just wanna go racing or atleast get on a dyno to properly tune it. Its been a year and I want to see what this new setup will do. If everything I calculated is right, the 70's should be more efficient and produce cooler charges for same given boost which will naturally mean abit more power. How much I am curious to find out. Plus as boost rises, they are capable of passing more airflow so its capable of being a huge hp setup but I'm heads/cam limited by a lot
#529
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Car: A lot and 86' Z28 and 88' Camaro
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Transmission: 700R4, th400 and 4L80
Axle/Gears: Frd 8.8 /3.27 and S60
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
I feel you on that. I'm still working on mine but should be up and running soon. I hate all the time spent wrenching and not racing. I grudge race so running my car means more than just having fun
#530
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
About 50 bucks for the fans. The shroud is the key too cooling on my setup. I couldnt get the stock fans close enough to the thick griffen rad to do any good. The shrouded LS1 fans really help draw in air. Both fans on, with warm 70's deg weather, my 401 stays around high 180's in worse case scenario at idle in traffic after a long drive to heatsoak the engine bay, and can get down to low 160's at highway speeds but I turn 1 fan off to keep it at 174 or so
#531
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Well i dont have a stock rad, nor is it in the stock location really...close but slightly moved, so I had to cut up the fan shroud to get it to fit. If you use a stock rad, i dont see a problem getting it to fit. Its same overall size as a TPI rad.
With both fans off, on a warm day the car will likely get up into the 180's to 190's range on the highway. I prefer to run colder...cold as I can really. I never drove for long period of time with both fans off. I've always ran 1 fan on and only use the other when I need it. I only turn the first fan on after I hit 170 deg anyway to keep it in the 170's.
With both fans off, on a warm day the car will likely get up into the 180's to 190's range on the highway. I prefer to run colder...cold as I can really. I never drove for long period of time with both fans off. I've always ran 1 fan on and only use the other when I need it. I only turn the first fan on after I hit 170 deg anyway to keep it in the 170's.
#532
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Just found your buildup thread, Orr.
Excellent project, excellent documentation! A delight to read about it.
-Dan
Excellent project, excellent documentation! A delight to read about it.
-Dan
#533
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
THOSE ARE SOME MASSIVE TURBOS! Thos are properly good turbochargers. You got that thing down here yet? I gotta see it.
#535
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Hay man you should try to get it down here for this Saturday. HUGE car show at Katy Mills. You could park next to the 2009 900+HP Hennesey TT Camaro that comes.
#537
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Re: Twin Turbo 400 Buildup- '89 Iroc-Z
So your running 9.86 @ 141 mph with a TH400 and a 4th gen 2.73 rear, what is your rpm's roughly at 141 mph. I might go TH400 with some tall gears like you instead of a 4L80E w/ 3.42's or 3.23;s because of having to cut the trans tunnel to fit the 4L80E into a 3rd gen. What are your rpm's crusing on the freeway at 75-80 mph? as well ?
#538
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
So your running 9.86 @ 141 mph with a TH400 and a 4th gen 2.73 rear, what is your rpm's roughly at 141 mph. I might go TH400 with some tall gears like you instead of a 4L80E w/ 3.42's or 3.23;s because of having to cut the trans tunnel to fit the 4L80E into a 3rd gen. What are your rpm's crusing on the freeway at 75-80 mph? as well ?
#539
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Ok, to update this thread...
Over the course of the last few months, I've been lucky enough to make it back home to PA to work on the car. I mainly tuned it more and more and got the driveability alot better than it was before. I no longer have the overheating issues I did in 2010. No more oil leaks either
April this year was rained out alot so my first track days were in June and July. Car went a best of 10.24 this year at 138 and has hit 140 again but its taking 2-3psi more to run the same times it used to with the old 60mm turbos. I have 70mm now and its just too big for the motor.
Logical solution: sell the turbos and get the old ones back. Practically cost me nothing, and i'd be back where I was in the high 9's. But I"m not logical
I knew my heads/cam were small for a 400 inch motor so I am replacing those and porting the intake out to match.
Its go big or go home, as there are alot of fast boosted cars in my area now and I must compete. I'm stepping up my game with a set of Speier Racing heads v2.72's.
http://www.speierracingheads.com/RHS2.72.htm
245cc, 2.100" valve, valvetrain built to my specs. Milled to 64cc. 317cfm by .600" 330cfm or so by .700". Its based on the RHS casting but a custom cnc program was made by Chad Speier for these heads. Heads should have been ready to ship today but I did not get a call from Chad yet to finalize information. Oh well he's busy These are likely the largest head that still use standard rockers available and have made 800 hp n/a on race 400"+ motors
For the cam, it will be another hydraulic roller, but I'm going back to my old 383 cam grinder. The design has been finalized this week, and will be cut/ground soon. Not sure of the specs yet, but its likely going to be over .600" and well over 240 deg duration. I wanted peak near 6400-6500 rpm so the cam is going to be big, but we shall see.
Valvesprings/valves/retainers are all selected to work with the lobes. Not using hollow stem valves but am using small diameter springs and titanium retainers.
Things will be interesting next year. Should easily be a 1000+whp capable setup although I only wanted 150whp more on same boost settings, which it should do. Should be 150mph+ traps and street driven
Over the course of the last few months, I've been lucky enough to make it back home to PA to work on the car. I mainly tuned it more and more and got the driveability alot better than it was before. I no longer have the overheating issues I did in 2010. No more oil leaks either
April this year was rained out alot so my first track days were in June and July. Car went a best of 10.24 this year at 138 and has hit 140 again but its taking 2-3psi more to run the same times it used to with the old 60mm turbos. I have 70mm now and its just too big for the motor.
Logical solution: sell the turbos and get the old ones back. Practically cost me nothing, and i'd be back where I was in the high 9's. But I"m not logical
I knew my heads/cam were small for a 400 inch motor so I am replacing those and porting the intake out to match.
Its go big or go home, as there are alot of fast boosted cars in my area now and I must compete. I'm stepping up my game with a set of Speier Racing heads v2.72's.
http://www.speierracingheads.com/RHS2.72.htm
245cc, 2.100" valve, valvetrain built to my specs. Milled to 64cc. 317cfm by .600" 330cfm or so by .700". Its based on the RHS casting but a custom cnc program was made by Chad Speier for these heads. Heads should have been ready to ship today but I did not get a call from Chad yet to finalize information. Oh well he's busy These are likely the largest head that still use standard rockers available and have made 800 hp n/a on race 400"+ motors
For the cam, it will be another hydraulic roller, but I'm going back to my old 383 cam grinder. The design has been finalized this week, and will be cut/ground soon. Not sure of the specs yet, but its likely going to be over .600" and well over 240 deg duration. I wanted peak near 6400-6500 rpm so the cam is going to be big, but we shall see.
Valvesprings/valves/retainers are all selected to work with the lobes. Not using hollow stem valves but am using small diameter springs and titanium retainers.
Things will be interesting next year. Should easily be a 1000+whp capable setup although I only wanted 150whp more on same boost settings, which it should do. Should be 150mph+ traps and street driven
#542
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Same bottom end, nothing changed. Just heads/cam/intake and the intake is same but with port work to the heads.
I really hope it can get 150+ mph on straight pump gas but meth injection kit will be added if necessary. i have the pump, just need nozzles and lines. I'll weld on some bungs and plug them for now.
I really hope it can get 150+ mph on straight pump gas but meth injection kit will be added if necessary. i have the pump, just need nozzles and lines. I'll weld on some bungs and plug them for now.
#544
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
I know, but thats what the cam guy and Chad Speier agreed on. They said I couldnt go big enough I was looking at the 220-227cc offerings at first but I was convinced to try larger.
They have these heads on a 383 motor (not sure if its a conventional 4.03" bore or not) on 13psi from a 420 megablower on methanol making 1100 hp at 7500 rpm! I'll be turning near 7000 shifts likely. Probably going back to the .96 a/r housings I have. Spool may be delayed but when it hits, its gonna fly.
Got the cam today. Its 24x/25x at .050 so thats about where I expected it. BIG .6xx lift. Should be fun.
They have these heads on a 383 motor (not sure if its a conventional 4.03" bore or not) on 13psi from a 420 megablower on methanol making 1100 hp at 7500 rpm! I'll be turning near 7000 shifts likely. Probably going back to the .96 a/r housings I have. Spool may be delayed but when it hits, its gonna fly.
Got the cam today. Its 24x/25x at .050 so thats about where I expected it. BIG .6xx lift. Should be fun.
#546
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
keeping the same victor E efi intake but going to port match it out to 1207. Havent decided if i'll have Chad do more port work to it or if I'll just do the port work since its cheaper for me to port it, i just need the time.
#547
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Join Date: Jan 2010
Location: Ontario
Posts: 820
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Car: 1987 Trans am GTA
Engine: D1sc 383
Transmission: t56
Axle/Gears: 4.11
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Your an animal!
Subscribed, looking forward to the results.
What other changes are you planning on making, ei; tranny, suspension?
Subscribed, looking forward to the results.
What other changes are you planning on making, ei; tranny, suspension?
#548
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Nothing at this time. Car is already built. Keeping same trans/converter. Suspension has been done.
4" CAI for the turbos and maybe add my oil cooler but not in a rush to get those done. Likely going to add a tranny sheild/blanket to protect myself and may clean the engine bay and recoat it black to clean it up since it could use it
Next step will be saving money for a rear end!! 12 bolt or 9" i havent decided. I figure tho with no planned transbrake abuse, a 12 bolt should last. I mean the stock 7.625" 10 bolt lived awhile a 12 bolt should never break. Plus its easy to reuse my brakes.
May go with a 85-90mm TB if I can find one for cheap. Need to modify my elbow to fit it tho since its made for stockers.
May add some ports to the headers for back pressure readings. I have the bungs, just need to install it. I wanted to go aluminum cold side pipes instead of this mild steel exhaust tubing to free up weight and keep things colder, but we will see. If I can reconfigure my welder for aluminum and learn to tack weld the pipes that will be a big help and I'll have my buddy finish weld them.
May change the mufflers for something more quiet Keeping 1000hp quiet is just too much fun.
4" CAI for the turbos and maybe add my oil cooler but not in a rush to get those done. Likely going to add a tranny sheild/blanket to protect myself and may clean the engine bay and recoat it black to clean it up since it could use it
Next step will be saving money for a rear end!! 12 bolt or 9" i havent decided. I figure tho with no planned transbrake abuse, a 12 bolt should last. I mean the stock 7.625" 10 bolt lived awhile a 12 bolt should never break. Plus its easy to reuse my brakes.
May go with a 85-90mm TB if I can find one for cheap. Need to modify my elbow to fit it tho since its made for stockers.
May add some ports to the headers for back pressure readings. I have the bungs, just need to install it. I wanted to go aluminum cold side pipes instead of this mild steel exhaust tubing to free up weight and keep things colder, but we will see. If I can reconfigure my welder for aluminum and learn to tack weld the pipes that will be a big help and I'll have my buddy finish weld them.
May change the mufflers for something more quiet Keeping 1000hp quiet is just too much fun.
#549
Supreme Member
iTrader: (3)
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
A 1000 horsepower. Oh my. You can also step up to a monoblade throttle body if you feel the need. It would just bolt right up. On the intake you can always get the aluminum coated with a thermal ceramic barrier if you want to help keep the air cooler. See, I can think of a lot of ways to spend your money.
#550
Senior Member
Join Date: Jan 2010
Location: Ontario
Posts: 820
Likes: 0
Received 1 Like
on
1 Post
Car: 1987 Trans am GTA
Engine: D1sc 383
Transmission: t56
Axle/Gears: 4.11
Re: Twin Turbo 400 Buildup- '89 Iroc-Z
Nothing at this time. Car is already built. Keeping same trans/converter. Suspension has been done.
4" CAI for the turbos and maybe add my oil cooler but not in a rush to get those done. Likely going to add a tranny sheild/blanket to protect myself and may clean the engine bay and recoat it black to clean it up since it could use it
Next step will be saving money for a rear end!! 12 bolt or 9" i havent decided. I figure tho with no planned transbrake abuse, a 12 bolt should last. I mean the stock 7.625" 10 bolt lived awhile a 12 bolt should never break. Plus its easy to reuse my brakes.
May go with a 85-90mm TB if I can find one for cheap. Need to modify my elbow to fit it tho since its made for stockers.
May add some ports to the headers for back pressure readings. I have the bungs, just need to install it. I wanted to go aluminum cold side pipes instead of this mild steel exhaust tubing to free up weight and keep things colder, but we will see. If I can reconfigure my welder for aluminum and learn to tack weld the pipes that will be a big help and I'll have my buddy finish weld them.
May change the mufflers for something more quiet Keeping 1000hp quiet is just too much fun.
4" CAI for the turbos and maybe add my oil cooler but not in a rush to get those done. Likely going to add a tranny sheild/blanket to protect myself and may clean the engine bay and recoat it black to clean it up since it could use it
Next step will be saving money for a rear end!! 12 bolt or 9" i havent decided. I figure tho with no planned transbrake abuse, a 12 bolt should last. I mean the stock 7.625" 10 bolt lived awhile a 12 bolt should never break. Plus its easy to reuse my brakes.
May go with a 85-90mm TB if I can find one for cheap. Need to modify my elbow to fit it tho since its made for stockers.
May add some ports to the headers for back pressure readings. I have the bungs, just need to install it. I wanted to go aluminum cold side pipes instead of this mild steel exhaust tubing to free up weight and keep things colder, but we will see. If I can reconfigure my welder for aluminum and learn to tack weld the pipes that will be a big help and I'll have my buddy finish weld them.
May change the mufflers for something more quiet Keeping 1000hp quiet is just too much fun.
Good luck keeping it quite!
I am suprised the 400 can hold up to that sort of power level?
A scatter shield will bring piece of mind, I would use one.
I like the 12 bolts for street apps with posi, but if your going for a spool and mostly track use, I would think the 9 inch is a 'bit' stronger?
Most smaller mig welders can handle a little bit of aluminum welding, which is perfect in your case for spot welding or tacking pieces together. I would look into converting yours if possible.