Running that PCB and components open to environment underhood looks risky.

 

Solid state is a silicon device. Relay is a mechanical device. When you PWM that relay it bounces around when you turn it on/off. It arcs the contacts if you don't have a clamp/freewheel diode install. A relay is very inaccurate. Accurate control of a motor at sub 20hz control is not needed and that is why the relay works. The relay has a higher failure rate than a solid state (MOSFET, BJT, etc) device.

 

Exhaust gas temperatures and cylinder pressures will be changed when switching between the two. I dont know if he is racing this car and getting the last drop of HP or just playing.

 

The nomenclature that Chrysler uses is 'fan relay,' that is what they call it. In which I don't really care, why, because I know that it is a solid state high side switch.

Chrysler uses it to regulate the engine's electric cooling fan speed via PWM from the ECM/PCM. Works great to do the same for the alky pump.

RBob.

 

Again I fail at knowledge and engrish. Thanks for the clarification

 

it wont matter , i dont use the alky as a power adder , only as an extra cooling/saftey net

tune gets set with no alky , then ill setup the alky so it cools the charge further without messing with my afrs . this is my street car so it wont be running on the edge

 

been thinking about it , manufacture says its ok , its just a relay board for the arc 4000 , but im going to move it into the car


speaking of the car , lets just say its losing quite a bit of the front end over the next few days

 

what do u guys thing of twin 76's ptrim turbins with .81 housings?

 

My guess is that with a comp that large and smaller turbine it is going to spool soon enough to cause compressor surge. I am interested to see how it works out. If it ends up with surge at low boost then put in a cbv activated in the surge area. I just had to do this on an install to clean up surge at 0-3 PSI.


Is there conformal coating (goo) or clear coating stuff on the board?

 

Ah, didn't see where it said a Chrysler fan relay. I was thinking classic mechanical GM fan relay.

 

yeah im kind of torn atm , i shoudnt have bought the t76 i did , it was an impulse purchase and i grabbed one with the wrong turbine housing

this is the reasoning betwen buying an 88 for the track

so it got me thinking if i could just buy another matching t76 and make it work , or maybe sell off the 76 and just buy an s475 or something
if i wanted to do twins again twin 66-70mm is prolly what i should have

yeah the board has coating on it , but im moving the battery to the trunk so ill be moving the relay panel as well

 

Whos T76 is it and what are the specs ?

The kid I sold my other turbo stuff to might be interested.


-- Joe

 

on3/ebay/china true 76mm compressor , ptrim turbine with an .81 housing ,3" band vband outlet

 

80mm GT45 with a 1.15 ar will do you nicely

 

yeah but at that point im better of spending the extra few bucks on the s475, those 80mm gt45's are like 600+ each iirc

 

looks like im going with an s475 or an s480

thinking about a s475 with the billet wheel option and race cover

 

It's an ON3 T76? .96 or 1.10 exhaust housing ?


Sounds like the same one I have.

Compressor Wheel 76mm
.80 a/r
4' Inlet and 2.5' Compressor Outlet
Inducer- 76.71mm
Exducer- 102.36mm
Exhaust Side:

Exhaust Housing T-4 Flange:
.96 ar Exhaust Housing
3.0" Vband outlet
Inducer- 74.5mm
Exducer- 65mm


-- Joe

 

same turbo u have except instead of the .96 turbine its got an .81

 

Ohhh the exhaust side is .81.. So it would be good for TPI or something that needs to spool quick but not rev too high.

How much are you selling it for?

-- Joe

 

yeah
same price i paid for it 315$ its only been taken out of the box hasnt even been mounted on a header yet

i also have the t4 flange and 3 inch vband and clamp for it ill sell as well

 

Way to big unless you want 1200 whp

 

umm yeah not on this shortblock lol , 800whp will be just fine

 

Yeah just saying i dont think a small cube non race motor would like those turbos. They wouldnt spool well. The .81's would def help, do not need bigger. I run the mp p trim .96's and dont see full boost til 4200 but they start to make noise around 3600-3800. Just come up to 20 psi abit slower. Hit harddd by 4500 as converter opens all the way out.

My friends 6.0 notch runs the twin on3 76's on .96's as well. E85 and aggressive tune it will spool them but also takes alittle while. Hes been over 1050 whp with them

Not sure why you sold the other small turbos. A single 475 with the 83 mm turbine would work well, or even 7675 turbonetics or magnum 7675

 

the gt3076's were to small on the turbines they moved a ton of friggen air at idle , been thinking about the 7875 for 399 from vsracing but i may as well just grab the s475 and know it will hit 1000 crank

im sure i wont have trouble spooling it witht he 3800 stall and transbrake and if i do i still have that nx direct port kit i can put to use plumbing it on the hsr presents its own issues though , id prolyl have to make spacers to go under the plenum

 

You wont have problem spoolin a single 76 with one of those smaller 75-83 mm turbines with right housing

 

oh i meant the s475 with the t6 1.32 turbine

 

The S475 is a good unit. I would pick the 1.32 housing. With lots of digging you can find a JDere unit that has the "race cover" and have an HP-series wheel installed.

I don't know why china puts small turbines on big compressors. But then again, they undersize the comp housing A/R for a given wheel.

Check out the Garrett turbine flow maps to figure out overall flow. You typically want 45-50% turbine flow of the compressor flow for best power.

 

right now its a tossup between the chine 78/75 the china 80/83 or the s475

 

might as well get the s475. its a quality turbo, will make great power and you can get them upgraded with 80+mm billet wheels for under $500. a box stock s475 will give a stock block a workout.

 

Yeah but that t6 frame is huge lol

 

lol. yes they are huge, that is the only downfall in my opinion.

 

thats why i have a sawzall and plasma cutter and a welder................................ to make room for that big bitch lmfao

anyways over the next few days ill make my choice , cars on hold right now for atleast another week as the shop is packed full with farm equip its so bad u can barley walk threw the shop

any one of those 3 turbos should do 800whp , but its prolly going to be the s475 that i get so i dont have to upgade yet again down the road .


if anyone wants that t76 i got let me know im prolly going to put it up on ebay in the next week

 

i cut all that crap out and have a ton of room to work and on everything now.

 

When you cut that rad support and headlight bucket areas out does it weaken the fenders or front end at all? I dont think it would but i'm about to cut mine out for weight

 

i didnt notice anything at all. the metal that is in their is very thin and in my opinion has no structural support. i am redoing my rad mount and im going to tie in the front frame rails to add a little support.

 

i am going to build something similar to this. i got these pics from jakesperformamcefab.com those guys are very talented fabricators.

 

the reason i havent been working on the car lately


lil hard to fit it in the shop right now



since it was nice out today i worked on it a bit outside, made room for installing an s475

 

got a manual steering box comming , thinking about ordering up a motorplate while im at it

 

You are dangerously crossing into strip only territory.

9 seconds is wicked cool if it's got power steering, motor mounts, full interior, and it can make a 300 mile trip without over heating.

You start turning it into a track only car and you've lost your coolness.

-- Joe

 

i just prefer the manual steering , the motor plate was just a thought prolly wont do it. as far as whats a street car and whats strip only, as long as u can legally tag and insure it its a street car


case in point 9 second pump gas car




front /mid plates manual everything tag registered and street driven more then its raced

 

The state I live in you can tag and insure just about anything with a motor.

If the vehicle is 20 years old, emissions equipment can be removed. (yes, removed!) you an alter pretty much everything. The only thing they don't want is fuel cell's in the trunk for some odd reason.

-- Joe

 

Joe's got a point Dave. Nothing more cooler than a fast vehicle with full interior driven on the street, legally. Case in point, Sal's old 6 second twin turbo Dodge Viper, full weight, still has IRS too. This is the greatest and fastest street car on the planet, and it weighs more than your Iroc, running a drag radial too, 6 second car, so don't get too carried away bro with weight reduction and frame modification...

 

Im putting the power steering back on mine. Lol

 

Gives me hope that 7's arent to far from reach in a full body street ride lol

 

mines comming out to keep the wife from driving it , though with the skinnys on the front it prolly wont stop her.



rob its not about wiegth reduction and all that its about getting that big bitch of an s475 to fit lmao. reason i thought about the motor plate was so i could do single 5 inch off the turbine into dual 3 inch down past the engine , really dont want to dump a 5 inch downpipe infront of the front tires

 

Shouldn't be a problem Dave. I stepped up to an 88mm turbo and the hood still closes, just had to cut the downpipe a little because it was now hitting the firewall. I thought about cutting the rad support out too back when I started, but after seeing how fast some V6 guys are running with regular under the oil pan meeting on the passenger side setups, figured why give myself that extra work. Valve springs are too weak, and the tensioner pulley is chirping like a ten foot sparrow, other than that, very easy to work on, just waiting on outside temps to at least reach freezing to do it, which is sarcasm because its been like 0 degrees lately...

 

S475 can be put over in the battery tray area too.


It will be interesting to see how much ET it gains. I looked at your thread but the smaller turbo timeslips have disappeared. What was the ET with the old turbo? Gonna do chronicles of 8 sec thread with the 88mm unit?

 

How do you support the turbo? Make a brace to the frame, and then a flex pipe to the hot side ?

-- Joe

 

Basically what i did for my twins. May not need bracing but i felt better with it. Braced to fender

 

Too much leverage on aluminum heads IMO.. I'd brace it.

-- Joe