I am doing some engine bay rearangement and removing the AC box and trying to gain some room for possibly an even larger turbo then the PT88....thinking GT4788R... that turbo will not fit in the location I have mine so since I am removing the AC box.. I will be redoing the passenger side manifold and since I will have it laying around I figure I may as well just build another kit and keep this one intact as a bolt in for someone who may be interested in buying it.

I figure I can put a good package together for someone if they are interested. I figure use a TC78F1 turbo for the newer F1-trim turbine wheel and extra 2mm on the compressor side. it will fit exactly as the turbo that was on the car as far as downpipe and everything.

so if anyone is interested please feel free to PM me. I can work up a price on it including the turbo, wastegate, oil lines, and a BOV.

AC on mine is not hooked up because I put my intercooler where the AC radiator went. If you choose to go meth injection I would be happy to build piping to fit the turbo outlet to the throttlebody so keeping the AC is very doable.

Let me know if there is any interest.

I am posting here because most of you guys are interested in FI and knowing turbo kits are NOT available for our cars especially a front mount kit it may help one of my fellow bretheren out.

the hot side parts are made of 100% stainless steel so no need to worry about rusting. Plug changes can be done in without removing anything from the car. all connections are stainless V-band clamps and flanges. with a TC78 the car should be able to handle 21-22psi of boost to redline on a 350-355ci motor.. for larger cube motors such as a 383, I imagine it will max out at around 17-18psi with good flowing heads and cam. spool on it was in full by 3500RPM and it hits like a freight train.

I strongly recommend an upgraded fuel system with larger injectors unless you plan on running modest boost in which case just an intank walbro and some 55lb injectors would do the trick.

Chris

 

Why not leave the passenger side alone, and try to arrange the turbo placement in the driver's side? I guess I mean in the area currently (for stock c4's) occupied by the computer and battery? Granted, I am not looking at the physical size of the tubing you are using, nor am I familiar with the physical size of the turbo in question... but ocne you start to eliminate factory components, I believe some interest among potential buyers, will be lost.

I typically figure, "if you can stuff a large turbo and piping into the engine bay without removing any factory components (this doesn't mean you can't re-arrange it of course), than you got yourself a true streetable, daily driveable, c4 turbo kit". Otherwise, if you start to eliminate a/c components, you might as well go "all out" and just place the turbo in the most ideal position and fabrciate the rest of the c4's components around it.

I think it was the critical thinking of turbo-size, tubing-size, and general packaging that eventually sways the "masses" toward supercharging... again I do not mean to offend you at all Chris (and beleive me I WANT A TURBO C4), but practicality plays a roll.

 

If I thought I had a snowball's chance of selling my Procharger head unit, bracket, and accessories I'd love to get this.

 

Mr. Dave,

You can do it.. put it up and then come see me for a weekend and we'll put the kit on!


mnstrlt1,
the piping I am talking about selling relocates only a very few minor items such as the PS res. not the pump, and the AC dryer. as for fitting an intercooler up front, it is possible to do but a new radiator short enough to stand up straight like the earlier L98 cars had is necessary. this being said if you keep adding required items to something it begins to get further and further out of reach of most of the people who may be interested. so for a stock or even forged low compression motor methanol as an intercooler is a very good solution. for people like me who intended to run updwards of 25psi something has got to give.

the drivers side is not even remotely close to being the better place to put the turbo, HP Performance kit is a hack setup in my personal OPINION.

on my setup eveyrhting pretty much remains the same and it is very easy to have a few extra AC lines made and you keep all your accesories and can run a turbo up a T78 that is enough turbo to support 850rwhp or more on a built motor. my kit with heads and cam on 8psi was easily fast enough to meet the desires of 85% of the people who may be interested in it. a touch over 600rwhp is where I would put the number from experience and how the car felt. I just want more and I enjoy fabricating so going bigger and hitting a new goal is worth it to me.

there are a few options outn there for people to go with such as blowers, STS or Raptor kit when it is released or the HP kit but I have something tangible that could be installed this weekend if desired.. and it is far superior to anything available as we speak.. see the log file in my other post... show me a blower that hits 19psi at 3900rpm on this forum with as little expense as this turbo setup would be.. any who have done it.. and I am sure Aaron can chime in and will tell you it is an up hill battle to get a blower sized to make that boost and a drive system under the hood that can handle it reliably and consistently. the other advantage is when the car is out of boost around town the turbo is virtually invisible, no blower whine or whistle and it quiets the exhaust down a good bit for pleasant cruising. If you want someone to know not to screw with ya, hit the pedal and let it go and the sexy sounding whapuuusshhhh from the 50mm blow of valve venting air from a 78mm turbo will clue them in that they may want to consider picking that battle.

Long story short is not alot of offering out there to people with a C4 who like boost and want something a little bit different then a blower to do it. the uniqueness of a turbo C4 is pretty nice.. without the noise it is one of the most unlikely candidates to be packing such a punch so the sleeper effect is incredible and is extremely fun if your the one piloting the car and someone decides they wanna play a bit!

Chris

 

chris-

I completely agree that at about 8psi, you will probably satisfy about 85% of buyers. I must have been confused... I was under the impression that your other post on this forum was one kit, and this IS another kit? SO just to clarify, you're now going to sell the last project's tubing (headers, downpipe, etc) and start from scratch on this project with a larger turbo, correct?

I also agree that HP-style mounting is not ideal, I don't personally believe in rear-mount either.

I agree with you 100% regarding turbo efficency and sizing options to suite any one persons needs. A belt driven power adder is simply not going to "act" like a turbo. I am actually pretty concerned about my own blower combo only because the stock crank hub is pressed on and does not incorporate a key. If i was going to go "all out" with the blower setup, I'd proably do a D1 or a YSi (or equivalent) head unit, slot the crank for two key ways not just one (anyone familiar with blowers knows the trumendous amount of strain the crank snout and key way are taking in "higher" boost applications), and go cog'ed or at least step up the crank pulley to an ATI pro-damper. I wouldn't go to that extent for serious power prior to considering a turbo myself! Keep in mind, I am a fan of turbos, I'm not trying to argue that superchargers are better. I think the major fear (that I have seen with a lot of different cars- not just corvettes) is that the turbo-for-the-aftermarket is relatively new. Most guys (that are capable) end up going DIY, and it's at that point when most guys are pretty much on their own with certain things (trouble shooting). the amount of manufactorer support/customer experience with superchargers is also a "selling" point.

to make a "simplier" turbo kit, have you considered developing some sort of "log" style headers? It would yield a much more compact package around the block. Again, I know that for "all out" performance, individual runners are certainly more efficent, but we're talking about making a kit that is easy to reproduce and inexpensive to purchase.

My rough Idea of costs involved for a turbo c4 (done right)

standalone ECU $1500-2500
injectors 60#-larger $400 - +
Gt4788r turbocharger (as used in your example) $3500?
http://www.extremeturbosystems.com/p...oducts_id=1433

procharger blow off valve $415
tial 44-48mm wastegate ~$500
NGK plugs $12(ea)
this doesn't even include the dyno time for tuning, tubing, install...

 

there is no way a GT4788R would ever be considered in a production kit.. the market would never support it and anyone at this level is so far involved in the build like you said they are likely building it themselves.

the kit I have designed and built, this is the third generation of it and each generation got better and better.. mainly because I am one who has problems leaving well enough alone and building them to me is as fun as tuning and driving them.. so for me to get where I am at here, it is actually cheaper and easier for me to say screw it cut up what I have already built and modify to suit my needs on the new setup reusing bends from this last build.

but I thought to myself I am sure someone who doesn't have the means to build a kit like this may be interested since it is ready to go on a car and tested on my own.. it isn't an idea it is a working setup which has gone 20psi already.. not sure if you have ever ridden in a built forged fuel systemed head/cammed car on 20psi, but let me tell ya it is another realm then a procharger base kit a 7psi or even 12psi for that matter.. a car at this level is downright frightening even from the drivers side. it requires deliberate undivided attention and respect.. in a turn it will kick the *** end out easily at 65-70mph even on the gentle bends of an interstate. as Aoron stated in my other thread there really isn't a way to put into words what the car feels like.. it is an experience you must feel first hand.

For me it was a ride in a big single turbo Supra pushing 850RWHP.. until that point I thought I understood what fast felt like. I was grossly mistaken. when he rolled into it in third gear I was reaching for handles, doors, seatbelts, anything at all, but what I was truly grasping for was clarity because everything I had known until that point was now null and void and I had just been educated what TRUE FAST really was. and there is even faster then that out there although it usually doesn't come in a street trim package and happen on a highway..lol

anyways, got off topic.. this is a good proven kit that I would ALWAYS take care of in the event something needed attention on it.. I have been a member hear for 10 years now.. I am not going anywhere except maybe one day to the C6 or C7 section of FI..lol but I will also likely pop in here to help where I can!

Chris

 

Chris-

Thanks for the clarity. I think you're definately a class act, and "if" I was in the market for a custom turbo setup, I'd be all over your kit!

I haven't had the pleasure of driving or riding in something with that kind of power. I am having traction issues NOW, let alone double the power! I can't imagine how you keep that thing going straight when you want it to go straight. At that power level, I am also interested to know how the rest of the driventrain hold up?

I really am impressed by your craftsmanship, turbo knowledge, and dedication to provide the c4 community something different and fresh! Obviously, since the c4 hasn't been the "it" vette for some time, it's hard to get larger manufactorers interested in making newly developed performance parts.

 

Chris,
I agree with everything you have said above. This combo may not be for everyone, but the person that buys it will have one very special, very fast LTX series vette. Again, as said prior, this sort of power is not easily expressed in words, you just need to experience it to understand!

You said something above that stuck with me, that I 100% agree with.
"A car at this level is downright frightening even from the drivers perspective. It requires deliberate undivided attention and respect. In a turn (or straight) it will kick the *** end out easily at 65-70mph even on the gentle bends of an interstate."

This is so true. When I am driving the '87, you are hyper-aware of every move you make, as the slightest mistake could easily cause the back-end to try to come around on you. Don't even begin to think of taking the car out in the early morning (moisture on the road) or when there has been any rain. It is just SCARY! 8 psi boost by 3000 RPM or nearly 20 psi by 4000RPM get's your attention in a hurry in a car that delivers 480WHP normally aspirated.

Good luck on your sale, as I know there will be a very happy, boost junky in the future.

This board may see a few new turbo entrants before too long.
Aaron

 

I have a pair in the oven going into a C4 with a 4L80E and a 9"

John

 

So I have been looking into C4 turbo options just today, and have only owned my 87 Vette for about 2 months now. I was pretty disappointed in the selection of turbo kits out there, or should I say lack there of. All I am really looking to do is boost my Stock L98 7 or 8 psi... I think I want to leave the cam and heads alone.

Is there anyway your kit would benifit me??

 

for what little you want to do I would steer you to a blower kit honestly.. unless you are looking to grow into some bigger power, it would be a bit involved to retrofit it onto your L98. the rear mount may also be a viable option...

for my kit, a full accessory swap would be required to make it fit. I am currently talking about just that with another forum member who is interested in putting it on his 1990 L98. Your radiator is also a vertical mount if I remember correctly the years. that also wouldn't work with the intercooler setup. it could fit but it would be a bit more involved then a simple bolt on!


Chris

 

Thanks for the input, I've read about the rear mount turbo kit, but I don't think it is available yet, unless someone else knows something I don't?!

 

There is something that confuses me.

i know that STS and Raptor are trying to put together a rear-mount kit, but what's the reason for it being so tough to pass emissions? I thought (pre-OBD-II) pass as long as the sniffer is good, the gas tank holds pressure and nothing under the hood (in relation to emissions) is altered?

To further understand the question, how does one get away with passing emissions if they choose to do a custom (one-off) turbo kit like the one presented here?

 

Chris,

I'll send you a PM.
thanks

 

There is something that confuses me.

i know that STS and Raptor are trying to put together a rear-mount kit, but what's the reason for it being so tough to pass emissions? I thought (pre-OBD-II) pass as long as the sniffer is good, the gas tank holds pressure and nothing under the hood (in relation to emissions) is altered?

To further understand the question, how does one get away with passing emissions if they choose to do a custom (one-off) turbo kit like the one presented here?
mnstrlt1


I'm planning a custom tubo install also and have pondered the same question. Would you cover me also?
Thanks,
DaveW

 

[QUOTE=mnstrlt1;1567817410]There is something that confuses me.

i know that STS and Raptor are trying to put together a rear-mount kit, QUOTE]

Front mount kit > Rear Mount kit.

More power, retain your spare tire, no clearance issues.

Wait for the front mount kit.

 

Hey Guys!

Sorry I have been a ghost lately, but I took a new job at National Speed Inc., a very well respected speed shop here in wilmington, and I have been installing the new PT88mm turbocharger on my existing kit for some more dyno trials for power output. I currently sold the kit to FinnC4, and am trying desperately to get the rest of the odds and ends tied up on the PT88 install. it require a different radiator (Griffin Scirocco double pass 13" tall unit) to get any kind of filter on the slant back radiator cars but the vertical mount radiator cars should have no problem. Since I sold the kit with the PT78HPS turbo (811rwhp 856rwtq), I did not want to alter any of the existing intercooler piping so I was forced to fabricate new piping which I have been doing for the last week, so far I have both pre and post intercooler piipes fabricated as well as new hard pipe coolant hoses to accomodate the new radiator.. I have left to fabricate the 4" downpipe and I am building a new exhaust system out of aluminum tubeing from the transmission back. I expect to have it finished by the end of next week and on the dyno by Thursday or Friday providing everything keeps going as smoothly as it has been.

National Speed is having an Import Vs. Domestic Dyno shoot out on the 24th, next Saturday and I plan on entering the car in that and then afterwards bringing it home to begin removing all of the turbo kit to start packaging it up for its journey to Finland to its new home. I will snap some pictures Monday or tuesday when there is something to look at and the new pipes are all on and the new radiator shroud is built..

will post back soon guys!

Chris

 

pm set. many ??? for you and your kit. Thanks Douglas

 

Would your kit fit an 85 keeping the AC? If so how much?

 

I have bin readin All this !!!!!!! BUTT!! I'M Goin to Stay with my ........"NITROUS".....LIKE THEY SAY "MORE BANG FOR THE BUCK"!!!!