Long Awaited Turbo build...

[JeremyH]

From this info im pretty sure im going to a .81 ar housing for this 67 then, is the p trim really that outdated?

 

[TurboPete]

Well n/a i was taking it to 68-6900, now im only going to 6500, and i have a frpp oil pump with tss gears

Ok thats better. I thought you had a stock oil pump.

Just take a good look at your graph and make sure your not buzzing the motor past its power curve were its really not doing anything .


Dont worry about the smaller housing, but like I said you have a 67mm which spools easily , your heads and cam combo allow for power past 6000 so a .96 will work fine , the .81 will hit harder .


Pete

 

[one eyed willy]

ive tried .68,.81 and .96.....didnt feel much of a difference between the .68 and the .81, but there was a huge difference with the .96, alot more lag. so i used the .81 for more relief of the back pressure. i really need to get a ball bearing turbo and would love a 67mm.....i think this master power 70mm is just a natural born dog off the line, makes good power top end wise but off the line it seems to just not spool fast enough.

does the 67 precisions have 4"inlet and 2.5 cold side with 3" v-band for exhaust?

 

[JeremyH]

Ok thats better. I thought you had a stock oil pump.

Just take a good look at your graph and make sure your not buzzing the motor past its power curve were its really not doing anything .


Dont worry about the smaller housing, but like I said you have a 67mm which spools easily , your heads and cam combo allow for power past 6000 so a .96 will work fine , the .81 will hit harder .


Pete

Yeah there was no drop off up top, actually im looking at the graphs going over them now and it looks like theres 10-20hp gain from 6000-6500 on both the 9psi and 12 psi pulls. More noticeable on the 12 psi pulls. Theres also an uptick in torque there too hmmm

 

[JeremyH]

ive tried .68,.81 and .96.....didnt feel much of a difference between the .68 and the .81, but there was a huge difference with the .96, alot more lag. so i used the .81 for more relief of the back pressure. i really need to get a ball bearing turbo and would love a 67mm.....i think this master power 70mm is just a natural born dog off the line, makes good power top end wise but off the line it seems to just not spool fast enough.

does the 67 precisions have 4"inlet and 2.5 cold side with 3" v-band for exhaust?

Precision's journal bearings are actually really great unless you just want the bb.
The hotside i have is a t4 tang footprint, true 3" vband outlet (actuallty measures closer to 3.5" outer diameter but a 3" vband worked fine, and a 76mm p trim exhuast wheel.

The 67mm coldside is an e-compressor cover, its actually the same compressor cover used on 60-63mm turbos. It is 3" inlet 2" outlet (60 ar)


Here is a list of the precision exhuast housing trims and sizes
http://www.horsepowerfreaks.com/partdetails/Precision_Turbo/Turbos/Turbine_Housings/T4_V-band/11618

Trying to find some spec on the compressor covers

 

[JeremyH]

Precision has like 20 different 67mm configs listed lol
http://www.horsepowerfreaks.com/par...Turbos/Turbos_Only/T4_Performance_Series/5948

Not sure what size the different compressor covers are yet.

 

[Mike Rousch]

If you're wondering about exh backpressure, just measure it. It's not hard to do at all. You'll likely have difficulty measuring much of a difference between the .96 and the .81. You will however get the turbo to spool earlier/faster with the .81, with little if any actual penalty in terms of power. It's a win win situation- with better response the car will be faster overall. The first time you get spanked good by a "lesser" car because they jumped out several lengths on you initially (while you waited for your impressive ferris wheel turbine to spool) will help drive the lesson home

Point is, putting up with excess wait is just not necessary. So why do it.

Its called spool in a bottle

The Ford boards in particular are generally a bit out of whack as far as turbine sizing and backpressure mythology. Historically, the Fords were also very late to the turbo party as well, so not a big surprise either really. Not a dig, just an observation over the years. Que sera.

I have to disagree, We were playing with Big (back then) turbo's in the mid/late 90's. Me, John Urist, Chris Derick, Mike Murillo just to name a few all had low 8sec small tire cars(28x10.5) with 91mm's and no boost controllers at all before 2000.

I measured over 50 psig backpressure on my turbo streeter back in '97, with about 26 psi boost. Backpressure is just a fact of life with streetable turbo setups. That's what powers the compressor (via the turbine). It does not keep you from running successfully, even with a "bad" camshaft choice.

A 2-1 back pressure reading is about as good as gets. Most of the street kits designed now a days are going to be a bit higher then that.

 

[TurboPete]

ive tried .68,.81 and .96.....didnt feel much of a difference between the .68 and the .81, but there was a huge difference with the .96, alot more lag. so i used the .81 for more relief of the back pressure. i really need to get a ball bearing turbo and would love a 67mm.....i think this master power 70mm is just a natural born dog off the line, makes good power top end wise but off the line it seems to just not spool fast enough.

does the 67 precisions have 4"inlet and 2.5 cold side with 3" v-band for exhaust?

Dont worry about the 2.5 cold side , the Turbo Pressure side can be 3" , all you need to do is buy a coupler that goes from 3.0 to 2.5 . Thats how I run mine no big deal .


Pete

 

[GB10]

ive tried .68,.81 and .96.....didnt feel much of a difference between the .68 and the .81, but there was a huge difference with the .96, alot more lag. so i used the .81 for more relief of the back pressure. i really need to get a ball bearing turbo and would love a 67mm.....i think this master power 70mm is just a natural born dog off the line, makes good power top end wise but off the line it seems to just not spool fast enough.

does the 67 precisions have 4"inlet and 2.5 cold side with 3" v-band for exhaust?

What RPM do you see full boost? Are there any issues or other complaints you have with the T70? I thought about trying out a Masterpower T70, but I've been leaning more toward the BW S366 turbo as it supports more power with a 66mm compressor wheel. Plus, I like how it has a 3.5" v-band outlet rather than 3". I'll be starting my turbo build soon after I build my motor which should be within the month.

Here is a link to the BW S366:
http://www.bullseyepower.com/S300.asp


Lighblade,

Is the fuel system still working good for you now that you've driven it some? I may do the same thing since my friend can get me the pumps from his dealership for cheap. Also, I read you writeup on the pump install, but saw no mention of where the y fitting came from to plumb the pump discharge on both pumps together?

 

[rford426]

I wanna know too willy I planeed on the going with the t70 as well

 

[JeremyH]

Lighblade,

Is the fuel system still working good for you now that you've driven it some? I may do the same thing since my friend can get me the pumps from his dealership for cheap. Also, I read you writeup on the pump install, but saw no mention of where the y fitting came from to plumb the pump discharge on both pumps together?

Yeap workin fine, i see 30psi at idle/cruise, hits 40 at part throttle and once the cars warmed up and i get into boost wot i see 45-50psi.

Im at 75% duty cycle with both pumps running off the one fpdm right now. i would say 550-575rwhp is as far as i would go with this setup. I plan to add a second fpdm one for each pump when i try to push it any further than that.

Btw any of you gt500 setup guys have a stock fpdm and harness pigtail leftover?

 

[JeremyH]

I wanna know too willy I planeed on the going with the t70 as well

PT67 FTW!

 

[jodadejss06gt]

I can't wait to feel my PT67 go into boost when I get it here.

 

[ALLOY GT]

What RPM do you see full boost? Are there any issues or other complaints you have with the T70? I thought about trying out a Masterpower T70, but I've been leaning more toward the BW S366 turbo as it supports more power with a 66mm compressor wheel. Plus, I like how it has a 3.5" v-band outlet rather than 3". I'll be starting my turbo build soon after I build my motor which should be within the month.

Here is a link to the BW S366:
http://www.bullseyepower.com/S300.asp


Lighblade,

Is the fuel system still working good for you now that you've driven it some? I may do the same thing since my friend can get me the pumps from his dealership for cheap. Also, I read you writeup on the pump install, but saw no mention of where the y fitting came from to plumb the pump discharge on both pumps together?

you will love the s366 i had the bullseye turbo made awesome power and spooled fast

 

[one eyed willy]

I wanna know too willy I planeed on the going with the t70 as well

its a great turbo for the price....i see full boost around 3k in first gear....15-16psi currently!!

the turbo may have nothing to do with the slow starts at the drag strip......my best 60ft time is a 1.8......not spinning, but i have to be easy with it so i dont.....

 

[JeremyH]

Can you rev and make boost in 1st gear? I sat and reved my car to 5-6K and in made maybe 1 lb. Also when driving taking 1st gear too 6500 it only makes 6-7lbs max and it takes forever. 2nd, 3rd, and 4th will all make full boost (12lbs) and spools great. 4th gear being the best at the turbo loves mph and spools alot faster from the load. Is this common or any ideas?

 

[TonyN]

That's interesting about first gears lack of boost. Just curious, disregarding the lack of boost, how does it feel? Does it blow the tires off fairly easy/pull hard? It might actually be an advantage for you on the street, but on the track with sticky tires it will obviously hurt you.

I assume it all has to do with calculated load. In first gear you have much less resistance compared to 3rd and 4th. There for the engine doesn't work as hard and doesn't have as much exhaust pressure causing your turbo spool slowly.

If you are getting wheel spin, maybe that's effecting the boost as well?

 

[one eyed willy]

Can you rev and make boost in 1st gear? I sat and reved my car to 5-6K and in made maybe 1 lb. Also when driving taking 1st gear too 6500 it only makes 6-7lbs max and it takes forever. 2nd, 3rd, and 4th will all make full boost (12lbs) and spools great. 4th gear being the best at the trubo loves mph and spools alot faster from the load. Is this common or any ideas?

what gears you got?

only way i make boost just revving it is if i use the WOTBOX

 

[Bullitt357]

Can you rev and make boost in 1st gear? I sat and reved my car to 5-6K and in made maybe 1 lb. Also when driving taking 1st gear too 6500 it only makes 6-7lbs max and it takes forever. 2nd, 3rd, and 4th will all make full boost (12lbs) and spools great. 4th gear being the best at the trubo loves mph and spools alot faster from the load. Is this common or any ideas?

There's no load on your turbo if you have the clutch pushed in and are revving it hence the lack of boost. You may have said it already but what rear end gear are you running?

 

[Bobby]

you want be able to just rev it and make boost. you have to have the wot box and mat the gas to make load which makes boost. i can make 16psi in first gear, but i have a triple ceramic ball bearing turbo with an .81 exhaust side. here is the link to it. http://www.compturbo.com/products/index.php?folder1=Turbo_Chargers&folder2=CT43&product=CT4380