1) Front Mount with pipes running under stock k member.

2) Rear Mount with exhaust wrapping to help spool time.

Here are my requirements:

---Keeps A/C & stock k member. Really not interested in paying good money for an alternator relocation bracket
---Rear mount mustn't run too much slower than the front mount.
---The more ground clearance I can get the better. But, they're both going to be low... correct? So does that not help my decision makingi?
---Probably will be running a gt42 or gt45 76mm turbo. Can always run smaller if I go rear mount but still want to hit over 500rwhp at 8 psi with a small cam/slightly ported heads 347 motor.

Also, if I change cams (currently 220/224, .551/.551, 114) and get one to hit the rpm band at a lower rpm, will that help running a rear mount rather than not changing cams and running the front mount? Or if I went rear mount and turned up the boost 1 more PSI would that help 1/4 times as to running 1 PSI less on the front mount?

 

go front mount save the headaches

 

alright guys. sounds like it should be a front mount with pipes under the k? unless I can be convinced otherwise. do I have to relocate my alternator, and if I put the turbo where the battery is can I stay away from much work fabbing up the position of the radiator?

 

This is another post that will quickly turn into a front-mount/rear-mount dick measuring pissing contest

Here's my $0.02. Neither system you propose will give good ground clearance. The front mount with a DP under the K-member will be just as bad as the ground clearance from a rear-mount (which also goes under the K-member.) A front mount above a tubular K-member will give the best ground clearance.

A rear mount at 8PSI can easily exceed 500RWHP. I'm only pushing 5PSI and hit 453RWHP. 22HP fper each 1Lb of boost on average. I found 4 seaparate exhaust leaks leaks on my system since the dyno too.....so the numbers can only go up.

What your choice really comes down to is $$ and skills. Are you able to weld and thus build the tubing for a front-mount system to keep your AC? If yes, this is the best bet by far. Best power under the curve, best ground clearance (provided the aftermarket k-member mentioned before), etc. If your welding skills are non-existant, do you have the $6.8K for the APS kit? If yes, go for their front-mount kit and keep your AC.

If you answered no to the first 2 questions.....the rear mount might be for you. It's a bit cheaper in kit form and keeps the AC. The downside is longer spool times for a given sized turbo (usually 500RPM or so) + the issue of oil return. The latter is really the hardest part of making a functional rear-mount system. All emphasis on this board seems placed on heat retention and spool, but log manifolds and wrapping the crap outta' the exhaust helps narrow the gap from the front/rear setups a lot. Making sure that the oil return is able to keep up with the oil feed is the REAL engineering trick on a rear-mount system (and not a thing to be underestimated as a power killer + a pain in the a$$ ).

So, if able I'd vote front mount for the benefit of power under the curve and increased ground clearance + oil management. Otherwise, the rear-mount will make nice power and be a fun driver, provided the above issues are addressed.

Good luck whatever route you choose Again, just my $0.02

 

i agree

 

I saw your requirememts but a tubular k member is about $500 and solves a lot of problems for a turbo setup.I know thats a lot but $500 added to the total cost of a turbo system is'nt that much for what you get.

 

You will be more likely to hit your goal with a front mounted turbo setup. IF you go with a rearmount, buy a COMPLETE sts kit. Don't try and fab anything up or mix and match some parts together. I've seen way too many of these kits turn out making the power a decent heads and cam package makes (or less) and it turns into a giant waste of money.

If it were me I'd save my dough and get an OFI kit. If not, find a deal on a proven used kit. OR you could buy components from manufacturers. You could buy your hotside from OFI, and cold side you could put together or buy somewhere else. Oh and you're not going to find kits that go under the K-member, that'd be way low up front...most of them route between it and the engine block for the exhaust exit. Just keep in mind that whatever you do, there will be tons of stuff you didn't originally think of come up in the process. I bought what I thought was a complete kit...well it was in general, but I ended up rebuilding my entire motor and had to put together a fuel system, buy tons of heat tape, wrap, etc etc etc

 

Why the stipulations? 8 psi and 500hp..Why the big turbo also? 500 with a 76 is leaving a lot of power on the table. Why waist the money on a cam? Why waist the money on ported heads also?

Zombies car made in the area of mid 700's on average with a rear mounted 76, with a zo6 cam, and stock 317 heads, and oem manifolds, why would you want to change things?
The 700 hp he was making wasnt the same?

Any decent stock engine, I mean stock...stock cam, stock heads, etc, can make over 500 with a 67 turbo.

Your questions should revolve around what makes it a better car? Not power, power is easy. You didnt state your trans, your gear ratio, your weight, the tires you ll run on...or the size? If you answer michelin 18's or something and 6 speed with 3.73's....Ill slap you.

 

the motor in my car isn't stock. it's a forged 347 with a small blower cam @ slightly ported stock 806 heads. the trans is a m6 & I have the stock 3.42 gears, full weight. I'm not worried about the suspension or tire setup right now.

tubular k member would be great but I don't plan on lowering the car anytime soon and wouldn't be looking forward to changing those things out.

 

If your power goals are up to 600rwhp an sts kit will wrk, especialy with a built motor and decent boost and is easy to install but ground clearance will be little if lowered. I scrape on almost every speed bump. Front mounts will make more power though.

 

DOOD!!! If you are really trippin' on a $100 part then you should reconsider going turbo. You need a solid $5-6k MINIMUM to turbo your car. The $100 alt bracket is like flipping a quarter into your turbo set-ups "fountain". Make a wish!

 

Go front mount! My BMR turbo K-member is in the mail

 

I would agree. Get the kmember and do a nice front mount. Do it once and do it right.

 

no way DOOD!! everybody knows a homemade kit for $500

can make 1000 horsepower, to the wheels even. oh yeah, make that $600 because i had to relocate my alternator.

J/k....lovin the make a wish!

 

Turbo Technologies T-76 Street kit meets all of your requirements, I made over 680rwhp with a 4L65e and a 9". Its a front mounted Turbo with no scavenge pump needed, and only one 2.5" pipe goes under the oil pan.

Give them a call, they are listed ------>

Ryan K.

 

Procharger will save you a lot of headaches. But if you want to stay turbo, i think i'd rather have a rear mount than a front that runs under the K (That'd be a nightmare i'd assume for clearance) Also, keeping the AC and ditching hot engine bay temps will be in favor of the rear mount. Rear mount if you want turbo is my vote, procharger if you want a front mount set-up however its a supercharger obviously. Hope this helps! Stay away from custom setup also unless you have a lot of experience/fab skills, will be a nightmare in the end.

 

buying a complete kit wasn't the plan, especially when there's a turbo you've already traded for. true that s/c does save a lot of headaches.

costs, it's a budget kit that will be custom made.. not a "do it once do it right complete" kit. designing a turbo system & getting it to work right is much more fun that just buying one and installing it. hell I could probably build my own alternator bracket. I just don't want to spend a couple hundred on a little bracket for an accessory.

I'm thinking going under the k member isn't really any worse than having a rear mount system. with the rear mount you have to worry about people trying to mess up or steal your car &/or parts.

 

I'm curious about a few things. With a front mount do you have to run a traditional exhaust? Would it be too loud to just dump it in front of the K-member? I think there's room for a muffler up front to keep it quiet. If your car doesn't have to go through a visual inspection and they have no clue about it, why not?

Are there any street cars dumping the exhaust up front? I'd sure like to learn more about this.

 

look into the ptl/eBay kit. It's a great deal at only 800 for hot parts and then about another 2000-3000 to complete the kit itself. I'm debating on using a tc78 or a t70 with mine and upgrade later. Good luck

 

I was street drving my car for awhile with a straight 3" dump in front of the K-member. It is loud, but not crazy loud. It was louder NA. However, It feels louder in the car because the sound is coming from the engine bay. Also, the turbo sounds insane when it is like that(This and spool time is a plus). Another bad thing...It stinks.

I never had a problem driving the car like that. In fact I liked it, but my GF and the police were always nagging me. Now, I do have a full exhaust with cutout now, and I did route it under the K-member. To be honest, that is not the lowest part of my exhaust, and I have yet to hit it there.