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Callaway Twin Turbo ZR1 (nevermore)

rkreigh

Well-known member
Joined
Dec 27, 2000
Messages
216
Location
Alexandria VA
Hi guys,

since no one is building any Twin Turbo ZR1s anymore, I'm trying to get it done!!! I need help in selecting vendors and a technical approach. I have LOTS of turbo experience from my turbo buick days and have even hung around the callaway forums to learn as much as I can. I have been studying all the info I can get about the LPE, Mallett, and Callaway twin turbo ZR1s and even though this project WILL be expensive and a nightmare, I am determined and will raise the capital through some innovative business ventures.

please post here with any thoughts, here is the basis of my approach.

use stock 95 ZR1 manifolds with a "stub pipe" to mount two Buick GN turbos down low. I will probably use the stock "90 degree" knuckle and integral waste gate (ported) for ease of packaging. they are a bit restrictive, but power WILL NOT be much of an issue here.

use a walbro set of pumps and a dedicated oil tank/cooler to scavange the turbo oil, and keep any debris out of the LT5 in case of turbo failure.

mount the intercooler up front (spearco, twin inlet, single outlet) up front and fab a custom air box like LPE did. it keeps from having to relocate too much.

use a FAST computer to controll a MUCH larger secondary injector (83 lbs) with a wide band 02 sensor, retain the factory computer with a 220 cc injector for the primaries and a recal chip to lower WOT timing. I might consider having the just a custom chip made to eliminate the FAST, but I like the idea of the wide band 02 to help with fuel trim. Fast Lane went with an electromotive computer and a custom intake, but I would like to use the factory lt5 intake if possible.

use alchy injection to run pump gas and limit boost to 15 psi on the street, and use race gas at the track to turn up the wick. also considering some propane to help atomize the alchy with a fogger nozzle.

my budget for this project is about 35K. by using as much stock parts as possible, here's the breakdown so far.

368 (15K)
turbos, (less than 1500, way less if used)
intercooler (1500)
pipe bending/fabrication (8K) stainless ain't cheap
injectors (600, secondary 83 lbs)
FAST computer (2300)
tuning (2k, lots of dyno time)
fuel pump upgrades (400, two walbro 340s in place of stock ZR1 pumps).
walbro scavange pumps, plumbing (2k)


so far I'm up to 33,300 and NO labor (whew). now I see why the LPE TT cost 54K!!!

these are rough ball park prices, and obviously the labor will be another 10-15K so I have to economize a bit to meet my budget.

any and all thoughts are appreciated!!! thanks.
 

TAC

Well-known member
Joined
Feb 18, 2002
Messages
252
Location
Bothell, WA
Corvette
1987 Yellow Callaway TT Convertible & 2003 MY Z06
What a project. Good luck! What about the engine's compression ratio--do you feel the need to lower it or is the LT-5's ratio low enough that the engine can withstand the added pressure of the turbos?
 
S

Stan A

Guest
Suggestion

I have followed your travels around the different Forums and I agree that you have picked up many good ideas and concepts. However, if you have not started this projected yet, I suggest that you drop it and simply just buy a Callaway Twin Turbo car and build that out.

I don't say this without experience as I have been connected with several attempts to re-build regular V8 projects that just did not work out to the owners satisfaction. They spent a ton of money too.

Piecing the system together may seem to be almost easy and in some cases it is almost is but when it comes time to connecting the CPU system and the necessary programming is where the nightmare begans.

Callaway and Lingenfelter had A/C Delco help in this area for their projects. Can you get the same assistance?

Suggest that contact Doug Rippie and see what he is doing at this time. He too has connections with what we are talking about here. I believe that he may still be building ZR1 twin Turbos.

In the long run you will spend almost as much to build this car as you would having a well known professional group do it for you.

This is in no way a put down on your abilities. Its just the end results are what you are after and without the right kind of help previous mentioned, it will almost be impossible to achieve your goal.

I wish luck no matter which way to go.

Stan A
 
T

TurboLuigi

Guest
I really respect Stan's knowledge and judgement.

However, why the heck not!

If you have the time and money, go for it. I might consider it later too although I had plans to go for a Callaway CR-1 (but I am being *raped* by Uncle Sam for the 2nd year in the row).

One suggestion. The Callaway air intake plumbing it too restrictive compared to the Buicks. Go for fatter pipes and hopefully larger from mounted Intercoolers.

Good luck in figuring out how to replace the microfueler.

And get a couple of Japs to fit it all in the tight spaces :)

Luigi
 

rkreigh

Well-known member
Joined
Dec 27, 2000
Messages
216
Location
Alexandria VA
that's the advice I'm looking for. I have a DRM 90 for sale to finance this project, and the more I "hold it up to the light" I realize why LPE and others charged so much. I will definitely contact rippie as he knows I'm serious. I'm getting some inheritance cash and life is too short to wait for what you want, go get it!!!

a 415 on the bottle might work better for me. SGC is building them for mid 20s and while not cheap, they rock.

I need only need 800 hp as it's more than enough to hit 200 mph.

trying to pull that 6th gear.

thanks stan, very sage advice indeed. I will probably just save the twin turbo tango for my turbo buick. it's way easier to work on, and cheaper to build a twin turbo rocket block.

any other thoughts???, I have another party in VA serious about this too so I'm doing the research to see what can realistically be done. he has substantial "means and feduciary sources" as well. the IT profession has been good to us.

thx.
 
J

johnny

Guest
rkreigh,

I know a person who is the best off all, in modifying your Zr1. he als helpt a guy to make his cams for his 1300 hp vette.

He tested every Zr1 made by GM and he also was chief engineer at GM when they develloped the ZR1.

So, if you are serious I can bring you in contact with Geoff Jeal.

Geoff Jeal company is located in England.

I have seen some engines he has made, It's awsome!

uden_01.jpg

john
 

rkreigh

Well-known member
Joined
Dec 27, 2000
Messages
216
Location
Alexandria VA
thanks. Jeal did the code for the CERV III twin turbo LT5 and may have some custom pistons. lowering the compression is pretty essential. I have had some conversations with Bill Kirchoffer in Jeal of Ky about building the short block.

I would agree that this is a difficult project and best undertaken by pros. but if the cash becomes available, the desire is there. a 415 may be more doable, and I'm also looking at some custom nitrous systems. but the twin turbo project will be researched in any event as there are many folks interested besides me, and I hope to lend some expertise to make it happen, even if it's not on my car. a gent I know has a 125K mule to donate if the project can be determined feasible, he has the means as well and is serious. both of us have 2 ZR1s so we can take one off the road, for mods to the other.

I will continue to pursue suggestions on multiple fronts and gather thoughts from experienced tuners. someone may "step up" and be willing to work with us.

it would be a thing of beauty indeed. a man has to dare to dream IMHO. the twin turbo ZR1 is the ultimate for me, and worth the pain of the pursuit.
 
J

johnny

Guest
A friend of mine is now building a twinturbo pontiac, but that's no 32valve! I will ask my tuner what he tinks about it, he also design my new engine.

uden_18.jpg

john
 

Twin_Turbo

Well-known member
Joined
Jan 11, 2001
Messages
618
Location
Enschede, The Netherlands
Corvette
1982 Twin Turbocharged Red/Black
mallettzr1twinturbo.jpg


Well. that IS nice :D

This is done by Mallet

Marck
 
9

90Callaway

Guest
Wow, that's a serious plumbing job for the intercoolers. I like the idea of tucking them up front in the nose. They sit up on top of the engine on the Callaway and turn into huge heat sinks when the car is not moving at speed. Just what you DON'T want for a turbo (or SC) application!
 

rkreigh

Well-known member
Joined
Dec 27, 2000
Messages
216
Location
Alexandria VA
the plumbing is a very difficult thing indeed. putting the intercoolers in the corner of the nose involves reloation of the cooolant overflow and LOTS of stuff in the drives side.

LPE made a single duall inlet, single outlet intercooler which is bit more elegant and simplifies the plumbing.

I now have a LPE 368 93 ZR1 which will provide a better foundation for building the twin turbo car. In conversations with Graham, I learned alot of what NOT to do and this project clearly with be expensive, but with the 368 already done as a foundation, just custom pistons and a freshen of the engine will be needed which helps.

we are planning to use the 93/95 stock manifolds as a basline, short SS "stub pipes to position the turbos. graham was able to get the turbos mounted high enough to "drain back" the oil without a scavenge pump on the LT5 TT.

I will be talking with Norm and Paul more about their cars to get some engineering details and do lots of homework before doing a project of this magnitude. costs are in the 30-50K range with me doing LOTS of the work so it's not gonna be cheap.

but the bragging rights of having a streetable 800 HP zr1 that will run the numbers will be worth it in the end. the engine is the best thing GM has done to date, and 800 hp is what I need.

while gathering some engineering details, I will use some nitrous on the car to satisfy the need for speed in the interim.

any ideas or sources of fabricators or tuners interested in this project are welcome. tia for any comments.
 

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