well guys,

the newest edition to the stable is arriving on september 2nd... some pics are below.. it is not an LT1 nor LT4, nor LS1,6,7.. it is a different animal that I think will lend itself esxcellently to my new build!

who thinks 4 cams, is 3 too many? 16 injectors, 32 valves, 16 intake runners.. moderation is for candy asses! excess RULES!

this car in bone stock form laid down recently 334rwhp.. this is stock performance for a 1991 car.. very impressive to say the least.. with mild mods including headers a cat back exhaust, cat delete, and cam phasing along with a retune, these cars generally ar around 400rwhp without unbolting the heads or porting anything.. they respond extremely well to exhaust mods and with the removal of the 7200rpm rev limit, the power continues to go up. the stock motor is 8000rpm safe as comes from the factory.. a wonderful platform! I hope you enjoy the pictures!

Chris

 

LT5

Should be interesting....

 

I've always like those and wanted to see a twin turbo model. You'll have it all: cubes, rev's, and boost.

 

Yea dude... you got me thinking about this now! What kinda power/benefit would a setup like this have over a built LT1!!

Hurry up and get it done!! haha

 

I always thought those were cool cars. Please oh please though, ditch those hideous wheels...

 

You can always go single turbo too...

Nice car!

 

Fast Caddie,
thanks man.. sure should be interesting, I am already getting in touch with the VERY VERY few tuners that even will turn a wrench on these things.. the cylinders are forged aluminum sleeved with a Nikasil coating from the factory.. this CANNOT be bored or honed so resleeving is a must for a build. I am currently leaning towards the 368CI engine which retains the stock 3.66" stroke crank and pushes the factory 3.9" bore out to 4.00" so std pistons are more readily available and alot less expensive then having a completely custom set built. the new liners will come from LA sleeve and I am looking into a set that is again coated with the Nikasil for excellent scuff resistance with use of the 2618 forged pistons.. kinda cool that you use the cylinders to avoid scuffing rather then having to go with a weaker silicone based piston material.

Mike,
yeah man.. the revs are what is so appealing to me as well as the combustion chamber design being a henispherical type with centered spark plugs.. this combination is extremely detonation resistant and a higher compression ration can be run for maximum power over comvention SBC and LTx based chamber designs. the 368 cubes I think will work well with either a set of GT35R bb turbos or possibly even a pair of SC61mm units in a T3 flange with .68 housings. the manifolds are going to almost definately have to be a semi or full log style due to the 2" ports from the exhaust. another plus is the 4 bolts per primary flange.. there should not be any form of leaking going on here. the spread port exhaust design also will make the manifold fabrication easier as far as welding goes and the lack of spark plugs on the side of the head will also make design criteria easier to meet. no issues burnign wires or boots or with plug changes here!!!!! whoo hoo

Chris,
Honestly I think an LTx based engine can be made to keep up with one of this nature fairly easy.. the wow factor fo a tt ZR1 of course will be cool and the other key benefits are as stated above.. the plug locations, also the use of 4 valves per cylinder afford an excellent flow capacity and the lighter valves which are smaller but two of each per cylinder offer a larger curtain area for better low lift flow and longer and broader power and torque curves due to the RPM valvetrain limit being easily overcome without the use of ridiculously big spring pressures. also camshafts while extremely expensive for this motor..( bargain pricing starts at $750.00 per cam.. thats right cams will run you $3000.00 dollars on this engine) are really not necessarily needed as individual cam timing for lobe spread and timing can be adjusted for the application making dialing the right combination for turbocharging less expensive while retaining the stock cams.. this is yet another reason for sticking with the 368ci version.. the stock cams will work plenty well. this engine from the factory has a 7200rpm redline and with boost running it up a little bit higher to around 7300-7400 with ported plenum/top end and cylinder heads should yield some SICK power and feel very linear. did I mention having a long block built for this car for a stroked and big sleeve 415ci motor will cost you $30k? so I have to seriously budget this build out as it can start getting out of hand a little fast. hence the perfect candidate for turbocharging.. retain as many of the already stout internals.. forged crankshaft and forged rods.. replace the pistons which are cast with forged dished designs to drop the 11:1 factory compression ratio down to around 9-9.5:1 and stick about 14-18 pounds of boost to her and let her eat. I would like to take this platform into the mid 800rwhp range.

the other really cool thing is the fact that is has 16 injectors.. one for each intake port.. so retaining high Z injectors is pretty simple.. a set of 16 42lb or 50lber's will do famously. or I could use a simple fuel controller for the second set of 16 injectors which utilizes a map sensor such as the megasquirt to run while in boost.. more then likely I will investigate the integration of BS3 which has provisions for 16 injectors maybe a set of stocker and a set of 50lbers can be made to adequately fuel this beast. factory rails are fitted with -6an ends on each side of the rail so modding the fuel system should be straigth forward. I have done alot of looking and reading so far on this critter and am very much looking forward to the build.. I will post up pictures throughout the process!

5.0 this,
I have a set of new A-molds in boxes already prepard to go on the car when it is delivered next saturday... will probably have soem of the parts for the build before I even take delivery of the vehicle they will be going on.. how excited would ya say I am..lol

Real Quick,
there is one single turbo ZR1 which mounts the turbo in an awkward place.. not my style.. low twins is the look I am going for.. besides.. the engine bay doesn't really need too much more wow factor.. rest assured just because they aren't readily visible.. the way I push my cars.. anyone around will know immediately whats been done to it!

thanks for all the comments guys!

Chris

 

In theory, none, horsepower on a turbo car is dictated by your turbo, power difference between a twin turbo LT5 and the same turbo setup on an old school 350, ford 346, LT1, or LS1 SHOULD be minimal.

But, i say do it, just cause LT5's kick ***, and a TT LT5 would kick more ***

 

the head flow WILL make a difference.. thats why LS1 forced induction setup easily surpass LT1's you CAN get the LTx platform to perform but it is still an inferior cylinder head design as compared to the available flow you can get with the new port design.

that being said.. the ZR1 heads are even restrictive to a point but can be worked for better flow.. 390cfm from them is common with stage 3 porting, with the 2 ports being smaller.. velocity is easier to maintain without sacrificing huge port volume torque loss off boost.

Chris

 

The 4 valve heads will allow you to make more power at less boost. The pent-roof chamber will allow you to run more boost on pump gas. So, you get the best of both worlds: 18+ psi on pump gas, and a whole lot of power at 18 psi. Sure, you could put the same turbo on a Supra and make the same power, but it will be at 45 psi boost and C16. Heck, you could run 100 psi on a Briggs and get the same result, but it's not my cup of tea. My experience has been that things are an order of magnitude more reliable below 20 psi boost. And below 20 psi, I believe the ZR1 motor will prevail.

Anyways. . . the challenge will be choosing the turbo. In order to support the airflow required by 32 valves, a large-ish turbo(s) is needed, even at lower boost levels. You'll also need to choose one that's efficient at those boost levels and high flow rates.

 

Mike,

I agree 100%. that was the entire idea behind this platform for turbos.. it simply lends itself nicely.. albeit ridiculously expensive..lol

as for turbos.. I am going to have to see what fits in there.. gonna be a twin setup definately due to some rough packaging restraints for a single. if the T4's will fit, I owuld like to put some 61mm units in it perhaps in a BB version. what are your thoughts on the matter.. figure RPM in the 7200-7500 rpm range on 368-385 cubic inches and around 18 pounds of boost with fully ported head and plenum and 63mm throttle body bores. decisions decisions!

Chris

 

Those numbers will be nice You sould be able to see ~1000rwhp with two of those 61's. How is the low rpm tq on a ZR1? Is it sluggish below 4krpm? f so, you may want to a go litle smaller on the turbos to help with spool.

Jon

 

so...any progress on this beast?