JD_Z28

iTrader: (19)

What kind of diffrence is there between a rear mount and under the hood mount? I get people clowning me for having an sts kit, they say its gonna have alot of lag, is this true, it dosn't feel that way to me. So what are the major diffrences.

paspar2

All the pictures I've seen of the STS, the turbo is hanging off the back bumper. Way out in the open, completely visible, it's just not my thing. Don't have experience with whether or not it lags so I won't comment.

93formto98T/A

iTrader: (28)

With front mount you get in most cases easier access to work on it, it's more presentable such as when you pop your hood to show it, it will lose less heat between the manifolds and turbo which plays a big role in efficiency of a turbo, and theoretically have better throttle/boost response due to the much reduced length of piping between motor and turbo. JMO

Devil's Due

I've only had the STS on my car but I find that it has been engineered to keep up with the underhood units. I don't notice any lag difference between the two. And I like the fact that the engine bay isn't so hot and cramped. I also know of a guy whot got a custom underhood setup and it scrapes the road more then the STS due to alot of the piping running under the k-member. Plus I just think the people that give you trouble are just jelious of your STS.

TeeKay

I've seen some installs that are sorta Rube Goldburg looking, but most that I have seen done by good installers look just fine. As far as performance - IMO boost is boost. 346 LS1 making 600+ rwhp on 11.5psi ain't too shabby.

Pro's:
Cooler engine compartment
cooler turbo (bearings not a problem)
Don't need an after oiler for the turbo
Properly sized (STS) turbo doesn't lag any worse than front mount.
Easy install and removal - no manifold/alternator/AC rework
Has some natural intercooled effect
Less expensive for the same power level

Con's
Needs a little more turbo for efficient operation - not as much as some would have you believe. Standard kit @ 5psi gives 35% more hp (100+).
Turbo oil pump is vital to the operation. Pretty well solved.
Lots of tubing fabrication if a custom install.
Some don't like the looks of it.

IMO, it's a dynamite deal for street/strip. HTH

engineermike

You will get wildly varying opinions and dyno numbers, but not very many actual comparisons.

Jose at Forced Inductions built 2 cars identical except one was PTK and the other STS. The difference was around 20 - 30 rwhp in the 500 hp range. Expect the gap to increase as the power level goes up.

Mike

fastlt1

iTrader: (4)

STS is $1000 cheaper and sounds kick A$$. But PTK less lag, more power, and more potential.

PurEvl

iTrader: (2)

sts vette deep 9's, gto 9's and 10's lots of trucks low 12's etc etc. If its done right they will work..i myself had one that went over 700 hp at 14psi

JZ 97 SS 1500

iTrader: (2)

Umm, I will stay quiet as long as possible on this one.

engineermike, I love that we did the test long ago. Hell we had a front mount and everything before they we ever made for the STS's...lol. The HP gap was as much as 100rwhp at 14psi and lag was ~500-1000rpms worse. We have all the data somewhere in our archives. Its was nice to bolt the STS system on, run it 3 times on the dyno, then unbolt and bolt in a front mount kit and see the actual differences with the same turbo used on both. Never bothered posting it.....would have started a full out flame war...but we know first hand what is BS and what isn't. . We still do alot of work for the rear mount turbo guys and help improve on turbos they have. Their is much to be desired on the units used and we welcome anyone who wants to go faster, whether front or rear mount.


*** Disclaimer****Picture attached is just a joke guys...... It was sent to us by a friend of ours.

ddnspider

iTrader: (26)

ROTF!
STS's work if done properly....problem is that most dont take the time to do it right.They expect to bolt it on and have 600hp.It seems to take a bit more effort with a rearmount to get it to equal a front mount,but to each his own.For a streetcar they do well enough

hellbents10

iTrader: (10)

That pic is hilarious!!!! LOL!!!

nitrorocket

iTrader: (12)

Depends what you want. It is a fact that a front mount will make more power then a rear. It depends on budget and power needed. I chose a front because I wanted to build the most efficient setup possible to take full advantage of pumpgas.

bboyferal

iTrader: (9)

"You get what you pay for." Always true, never false.

TeeKay

Jose, no disrespect, but you said that "with the same turbo used on both". Shouldn't the turbo's be spec'd differently for the two positions? It makes sense to me that the same turbo in front and rear would have significant differences in performances. Yes, no? No argument, just looking for clarification. In my book, you have forgotten more than most of know.

Avengeance

iTrader: (4)

Would like to see the answer to this.

ABeasst

iTrader: (5)

He kept the turbo the same as to minimize the different factors so the numbers are more honest.

OUTLAWZ RACING

iTrader: (9)

I dont really care i roast 99.9% of the cars i raced frontmount rearmount god dam is this ever going to stop there's always going to be a better kit a better turbo a better dyno sheet. All these side by side test are sometimes bogus Even though i have a sts yes there are some things i like about it and some i hate about it i made good power and loved it two of my friends seen my car run and hell seen me roast people and bought the kit and loves it one is making 607 on a stock bottom with lq9 heads with 11 psi through an intercooler so and he ran a 1129 befor he did the boost upgrade Me when i get out of this hell hole Iraq Im shooting for 9,s my self and will race any haters DONT RUN YOUR MOUTH RUN YOUR CAR!!!! imo

smokinHawk

iTrader: (48)

when the turbo is "spec'ed differently" for the sts, what do they do, they use a smaller AR, so it sure boost faster then before but falls off up top ALOT faster, so your limited on HP, thats an easy answer, just not a good solution.

if you going to do a turbo do it right.

engineermike

That's true. The STS rear mount turbo's are sized the same as front mounts except the A/R ratio. The "correct" STS turbo would have a smaller A/R so it would spool quicker, but reduce power output. "Appropriately sizing" the STS turbo would have made things look even worse for it.

When I said I was doing a turbo versus supercharger comparison, everything else being equal, EVERYBODY said the test was invalid since I was using a supercharger cam and log header. When the turbo made 30 more rwhp, everybody said how great a test it was. If I had "optimized" the cam, then all other things wouldn't be equal, would they?

Mike

Frost

iTrader: (45)

From your own admission the cam was optimized.... for the SC... for a more realistic set of representative numbers why not cam each accordingly?