Guys,

I'm new to this site because I googled up a search on multiple turbo topics and found a lot of the posts here insiteful. I'm hoping the experience here also applies to non-4 cylinder motors, because, to be honest, there just aren't as many turbo mustang gurus as there are import turbo gurus.

I have a 331 (5.4 liter) small block ford. Consider my block and internals bullet-proof (dart + billet = ~1800hp capable).

Goals for the turbo/turbos:
1. Car is a street car with occasional track time: focus performance on the street. So rpm band will be low with a maximum limit of 7000rpm on the motor.
2. 8.5:1 compression ratio means I want to limit the boost at 15psi on pump gas.
3. Even though performance focus is on the street, I'd like to switch tune, and minor engine parts (injectors, plugs etc...) and push the car as hard as possible.

A local guy who seems to know his stuff reccomended a twin 67mm ball-bearing P-trim custom setup. I'm wondering if such large turbos will ever spool. These particular turbos, according to Precision turbos, whom I called, "are relatively new and will spool more quickly than 61mm std. bearing turbos will." What rpm range would you expect these turbos to spool at and reach a max boost of 15 psi on a 5.4L engine?

I want to make good power on race gas, but not at the cost of spooling on the street.

I think 700 whp is a reasonable expectation on pump gas at 15 psi. I don't know what to expect on race gas, but I'd like to make over 1000 whp.

Thanks,

Chris

 

twin gt40 t4

 

yeah id think twin gt40's would work pretty well on that set up...

 

Put my vote in for twin GT4088R's with a split housing, divided setup.

 

<--- was also thinkin gt40r's for his car. is there something wrong with all of us???????????

 

i wouldnt know much about for a V8 but dont a lot of supras use T70's? would that work well for mid range power on a V8?
-Josh

 

twin GT42R's..............overkill city!!

 

best place to go when i was into mustangs and turbos..

http://www.turbomustangs.com

-mike

 

I think there's a guy that goes by the name Wolverine at fuelslut.net who is running a single 4280 and making around 940 rwhp.

I looked at the compressor maps for 67mm compressors and found that on my app they would be to the left of the surge line and 5000 rpm or less.

A 4288 has an 88mm compressor wheel, right? If that's the case, I can't imagine my little 331 being able to spool two of them.

Remember, this is a street car,

Chris

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris Arnold &raquo;</TD></TR><TR><TD CLASS="quote">I think there's a guy that goes by the name Wolverine at fuelslut.net who is running a single 4280 and making around 940 rwhp.
</TD></TR></TABLE>


He is using a GT42R Super 76 101 A/R GTS Trim. Dyno sheet:

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris Arnold &raquo;</TD></TR><TR><TD CLASS="quote">
A 4288 has an 88mm compressor wheel, right? If that's the case, I can't imagine my little 331 being able to spool two of them.
Chris</TD></TR></TABLE>


they will spool.

you are using fuel injection on this car right ??

 

A single GT4202R should be nice.

 

I guess I should redefine what I'm trying to do. Since it's a street car, not a race car, I'm going to keep the power band down low in the rpm band. I'd like to come into full boost by 3500 rpm or less. While my internals are capable of very high revs, I think the car would be more driveable and more fun if it makes good power on pump gas at a low rpm. I think I'll limit it to around 7000 rpm.

A single 88mm turbo can be made to flow enough for 2000 hp. That's way more than I'm interested in making. Getting two to spool on a street car at low rpm would require no less than a BBF stroker.

Would you put an 88mm turbo on a low revving 2.7L engine? If not, then two will be too much for a low revving 5.4L engine.

Chris

 

super 76 101? What exactly does that mean? What size is the compressor wheel on his turbo? He made 940 rwhp at 21psi. That turbo must be used up since he only picked up 73 rwhp for an extra 9 psi of boost.

Chris

 

Talk to precision turbo. Alot of the Viper guys used to run dual GT35Rs, then 42Rs and now T70s.

 

dbb T66s

 

True, but Vipers also have 8.3 liters and are 10 cylinder motors that move a lot more air than a 331 does.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16hybridsol &raquo;</TD></TR><TR><TD CLASS="quote">dbb T66s </TD></TR></TABLE>

Do you know where I can find the compressor map for that turbo and who sells it?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris Arnold &raquo;</TD></TR><TR><TD CLASS="quote">True, but Vipers also have 8.3 liters and are 10 cylinder motors that move a lot more air than a 331 does.</TD></TR></TABLE>

check out stenod performance. on t66s and like 15psi they made around 800whp. ls1 car though

 

Were building a twin SC 61 LT1 right now. I talked to precision for a while and they should be good for 1200 max to the wheels but 700-800 should be pretty easy on pump gas

 

I personally think a single gt40-2r will do the goods...

 

twin gt28rs fast spool up good for 700hp, Lingenfelter uses them on their corvette setup.

 

what heads did you go with?
and cam? cam motion? most ppl seem to be goign with them lately

what tranny are you going to run too? tko or a c4 or a glide?

 

Sorry guys, I'm a noob on this site so I can only make a few posts each day. Therefore, I'm going to respond to everyone in this post.

Boosted94cx, I'm going to run AFR205 heads. The cam will be a custom deal from Ed Curtis. I love shifting so I'm going to try to stick with a TKO600 or MMR PT900.

DRAGLS, GT28rs are kinda close to the turbos I ran on my incon kit, and I think it'd be pushing them pretty hard to run 700 rwhp constantly on them.

Weq, compressor map?

10seccivic, good info and that's the way I'm leaning right now. Twin 61s or twin GT35R turbos (same compressor) are the way I'm leaning right now. Their in the 74-76% efficiency range throughout the rpm band. I'm wondering what single turbo would be right or if there is a better turbo for a twin application.

b16hybridsol, I checked out the website. It looks like they're using twin 60mm turbos. But I still didn't see any compressor maps or any specifics about them.

Chris

 

A guy from Speed, Inc. made 1000 RWHP at 20 psi and 725 RWHP at 10 psi on pump gas from a very very mild 347 stroker with a tiny hydraulic roller on twin 61mm ITS turbos. Them or GT35R's get my vote.



There's a dyno of twin precision SC61's on a 5.4 32V motor off of turbomustangs.com..............