Sundance 6g72 "3.0 turbo build thread"(N/A DYNO SHEET pics inside)

[Sundance 6g72]

okay, wideband ground fixed.. still read funny. I had the aem wideband calibrated wrong. MS has two preset aem wideband calibrations but neither worked with my unit because it was a different product. mine is the AEM 30-4100.

i looked in the instructions and it had voltage readings for every lamda value but nothing that helped me with megasquirt. i read deeper and found that the wideband reads from 10:1 - 18:1 (at least thats what the gauge reads. the output is a 0-5 volt so instead of telling MS that 0v = 10:1 and 5v = 20:1, i switched it to 5v = 18:! and walla, MS seems to read identical to the AEM unit. Cool, now i can have exact AFR values in my logs.

i think i have a loose motor mount, im going to tighten that up and replace my plugs in the next few hours. once that is done, im going to tune for 14psi again. my afr should be good in that area but when i did dial it in, my afr was off but i tuned accordingly. my Duty cycle at 14psi was in the area of 95ish. that was at 11.5ish air fuel ratio. Basically i can lean it out a tad to 12:1 if i want to, e85 wont mind that. i might just hit 14psi and give it as much fuel as i can until i go with bigger injectors.

My goal with these injectors and this turbo is to do over 300whp on 14psi. I want to say that these injectors will do 330whp on a good tune (taking into account that fuel pressure increases to 57.5psi at 14psi boost.


if i meet my goal, the next goal will be over 400whp.

- Precision 6076E turbo, t4 .68 w/ p trim wheel. 3inch downpipe (current is 2.5inch, i will sell this for CHEEP)
- 75# - 95# injectors. DIY has them for the same price.. if i go through them, then ill get 95#. It will come down to whoever can give me a deal. my 46# injectors will go up for sale at that point.
- upgrade pressure plate with my current 6puck disk? I have the stage 2 PP but i dont know if that will like the 400whp range.
- rebuilt trans. Turbos unleash apparently rebuilds trans, syncros and all. they want $650, im not sure how much shipping will cost both ways.
- 58mm throttle body, ported front manifold. those two combined with the 3inch downpipe i hope to make the precision spool as early if not earlier than my current turbo. current turbo has a 50mm inducer and a .63 hotside. spools alright, i was never satisfied by its spool for being so small but whatever. it was $150 shipped brand new


cams, lsd, slicks can all wait. I consider those to be things that can be added later especially when sometimes you can find a good deal and other times you cant. Im more than capable of putting an lsd in my trans so i dont need TU to do it for me.

what do you guys think? I want this setup to be able to produce 500whp but im only shooting for 400whp and maybe 450 if i feel like pushing it that hard. im sure 400whp will be enough to make me crap my pants for a while.

[nmw2006]

Clutch/Pressure Plate survival really has to do with how much torque you put down, not HP. TU Stage II (ie. Blue plate) is good for at least 350 ft/lbs with a 6-puck ceramic. I imagine you will be putting down more than that at 300whp, so an upgrade could be in order especially if your clutch has seen some abuse.

Also at that kind of HP (300+) I imagine you are going to be having problems putting it to the ground without a LSD/better tires or slicks. Especially at the track!

Our stock cams are really fairly impressive as far as turbo cams go, probably not a priority at all. They could use some more lift. Only thing I'm seriously looking into is getting rid of as much of the lobe separation angle (front vs. rear) differential as possible. With the staggered LSA cam setup you could be pushing your luck as one bank (rear?) is going to be leaner than the other. In other words your indicated 12:1 AFR is an average of both banks (ie. front is 11:1 and rear is 13:1) This is the biggest problem I see with the stock cams at high HP/boost levels.

Just my thoughts, others are welcome to disagree

[Irocelectric93]

Im going to guess that on 14psi you put down 350 or so without an issue. Even with only a decent tune this should be doable. Also remember that youll need a flyback board if you go with the 95s for injectors since they are low Z. Unless you've already gotten setup for Low impedance? i can't remember.

[Sundance 6g72]

i thought the v3.0 and v3.57 had flyback built in? Im running high z right now. seems like all diys big injectors are low z.


i dont think 46# injectors will easily flow 350whp. im running them close to the limit too... ill dyno when i can. i might be able to add more timing too, but i would need to pay for a tuning session for me to run the dyno as much as i want $$/hour


im curious to see how far apart the banks are as far as air fuel ratio goes... tire grip is not much of a problem in 3rd, sometimes they pull free at 14psi.. 2nd they rip free once i hit full boost but im already about to shift at that point. slicks and lsd dont need to be bought right away though.

i have not heard or smelled a burning clutch but i could be close to pushing its limit... who knows. i seem to build lots of boost by the time the NA torque curve is already at its peak. i think ill try and just get a beaffier pp

[Irocelectric93]

My bad. I forgot what size injectors you were currently running...even though you stated it in the previous post. I just missed it. Yeah...if you're maxing your injectors now it might be hard depending on what you're current tune is putting to the wheels. You may be right about the newer boards having flyback built in. I've never asked anyone nor have i been told...if you're right then i'll be super happy though.

[Sundance 6g72]

its all good.


so i might have hit 17psi. the tune should be able to handle that amount of boost but the injetors probebly wont supply enough fuel for it. idk how lean that would have been but im not going that hard again thats for sure. ran with alot of fast cars though. the car took a beating. its going to be treated nicely until i tear it down again...

i need to get my catch can installed again.. ive been putting that off and it bit me in the --- today with the boost i ran tonight. back to Wastegate pressure it is. i wont be suprised if im knocking next time i start the car but who knows, e85 does wonders and i might have been fine even if i was lean. i dont regret it though, the car got alot of respect tonight hahaha.

[shayne]

at the risk of looking like a fool, and going back on my choice to run a felpro perma torque mls.
i am swapping the felpro 24 valve mls head gaskets out for the standard felpro ones. simon dropped by and had a look at my issue, the oil return (on the front head, 2,4,6) next to the distributor on the lower passenger side was weeping oil on me, too much to be livable. and after distorting slightly being compressed, the coolant passage in the gasket on the upper passenger side of the front head was now exposed, simon remarked that it suprised him that it didnt leak like crazy there. he also said that the standard head gaskets are really good ones to run as far as composites, stating that they are similar to the 8valves' much coveted 005 head gaskest, reaffirming again what ordonti already declared about them.

the best bet would be to send cometic a stock 12valve gasket and have a custom set made to fit perfectly, i was hoping i would be able to get them to work like other people already have, and everything at first seemed okay, but it was a failure overall. dont want to thread jack, just wanted to pass along some information.

[Ondonti]

The Cometic barely seals next to the distributor. Barely!

I love the standard Felpro. Copper wire in the fire ring.

[shayne]

^yup thats what i experienced, so it goes to show that the cometic could potentially have the same issue as the permatorque mls i tried to use.
i wasnt aware that the standard ones used a copper fire ring, more good news.

[Sundance 6g72]

i think he means glueing the copper wire into place? i know he did that before to an mls gasket and it worked!


He mentioned that the cometic barrely seals against the dizzy.. not the oem mls gaskets. But ive never used either so who knows.

[shayne]

? i dont know, i know that the felpro permatorque mls head gaskets didnt work out for me in this case.

on a side note i see your new turbo aspirations, and i just wanted to say to look into the borg warner s300sx turbo's first either the 83 or 88mm version, they are a bit cheaper and lots of people are having great results with the t4 twin scroll exhaust, (quick spool, lots of flow for higher rpm power) you would need to change or modify your crossover pipe, and if you went the twin scroll way you'd need a second wastegate, but it has a lot of potential for big power and lower back pressure.

[Sundance 6g72]

I would love to go twin scroll but I'm not certAin it woulf work correctly without the right set of manifolds/header. Also. I thought any fancy BW turbo would run over $1000? I'm at work so I can't check prices. The turbo I'm looking at will give me my 400-500whp for under $700

[Ondonti]

I said what I meant. Read Felpros PDF about our motors. They have a copper wire inside the fire ring. The OEM certainly does not. What I did before was a steel wire in a used OEM paper gasket and a copper wire on an used 6g72 OEM MLS (which did not have a sealing problem). I have no idea where the MLS gaskets came from anymore but they were from something I took apart. I don't think they were turbo gaskets but something else (and very thin, like the 6g75 gaskets).
If Felpro MLS don't seal near the distributor then they are not cut exactly the same as OEM in that spot and its a deal breaker.

Been daily driving my Felpro composits for 1.5 years now on the Holset.

[Sundance 6g72]

i like the felpro too, it seems to work fine for me. I figured if im going to make a big jump in performance and drop all this cash into the motor and trans, $60 a pop for MLS headgaskets would be worth it. OEM of course.

so felpro composite, oem MLS. only real options

[shayne]

or custom cometics, designed to match the oem 12valve gaskets. they will do custom ones for the same prices as there normal 24valve ones, just gotta send them a stock type one, or a cad drawing of a oem one.

[Sundance 6g72]

idk if i like the idea of going with them. aparently their dohc headgasket was very poor in comparision to the oem mls. whats to say their sohc attempt will be any better?

[Ondonti]

or custom cometics, designed to match the oem 12valve gaskets. they will do custom ones for the same prices as there normal 24valve ones, just gotta send them a stock type one, or a cad drawing of a oem one.

What would be the purpose of even having a cometic gasket? People go to the extremes of beveling the pistons to avoid using anything but OEM MLS. That said I love the Felpro composite right now. 10 psi on pump gas and stock timing for a long time.

[Sundance 6g72]

i think im dynoing the car today.. hmmm


also got a new wip to DD. dosnt have a clutch but it has heated seats and looks nice. Nice to go to something like this after DDing a plymouth sundance that cant get out of its own way for 4 years.



Not sure what boost im on.. found a melted WG line, fixed that. prolly will end up running less boos than in the video ill be uploading really soon. should be ALOT of boost though. shooting for 350+ but who knows. might make 285 to the wheels for all i know. as long as its fast.

[RoadWarrior222]

Nice CTS, when's the supercharged corvette motor and brembo calipers going in?

[Sundance 6g72]

hahah. i would have found one with a 6spd manual but when i go to sell it, i dont think many people will want a 3.6L caddy with a 6speed getrag.