I should be at about 10.2:1 compression ratio with my current setup (62cc heads). My mods are in my signature for the majority of stuff.. What do you all think the most boost a TT setup could run safely?

With a swap to 74cc heads I can get down to around 9:1 - 8.7:1 range. Is that higher then desired still? What could I safely run? Could I do anything to get lower comp (without replacing motor internals), like head gasket, bowl porting, etc etc.

Local speed shop said they'd do a dual T04 kit for about $3500 installed with IC, all custom made, etc. I plan on getting new heads anyways, as well as intake. Figure I would do it all at once, but since it would be alot of $ to throw down I might get the TT kit now and do the heads/intake at a later date.

What kind of HP/TQ could I expect from the motor with pump gas? race gas?

Anything I should know before I start saving up?
As far as the guy that would make it, he does custom turbo setups for most anything, he has a new 6cyl eclipse in there, a badbehind porsche powered Dune buggy, and I've seen a few other cars by him, all nicely done and reliable. Tuning would be via a haltech (no problem for turbos there), and a guy that does haltech tuning on turbo buggies most of the time, many different motor combos... So not worried about reliability as far as that goes...

Thanks for any help, information, etc.
Matt

 

Whats this shop?

I maybe interested in doing this as well. I am about 40 - 60 mins away from you.

You will want a forged bottom end.
I am 10:1 as well. I would swap my heads for something in the area of 9:1 at the very highest. I would not want to push boost through this thing as well.

Keep me posted. I have a dead car as we speak... no time to put it back together from replacing head gaskets.

 

Its a place called Stafford Fabrications. He works out of a speed shop called Swat Peformance. The guy does alot of import stuff. His work is nice looking to me.
I just picked up my headers today from him, he made the 2,5" collector into a 3", nice welds, and he did it no sweat, didnt even seem to think about it.
If you talk with him (I dont have his number, I can get it for you though), dont mention the price I said, I dont know what it would normally run (dont know if he was cutting cost for me or anything).
Few things I know that helped with the price was: I have no AC, no Smog stuff, just a nice open engine compartment now, so plenty more room to work in, and room to mount an IC (where the AC condensor was). Also that the little stuff would be my side, run the stuff for guages, get the hoses for oil made, etc etc. He'll jsut do the fabrication and installation of the main parts (which is ok with me).
When I picked up my headers I talked a bit with him, he said 600rwhp should be doable on pump gas. And he said 9:1 and under would be best.
I need to contact Scat and see what they rate their crankshaft at for power. Being a cast crank it might not be able to take it. But then I have heard that Scat cranks arent normal for cast cranks...

I will try to get his number (he's a few miles away, so I just stop by instead of calling) if you are truly intersted.
As a note, they have a dyno in house, not the guy I am having tune mine though, but a good tuner still (he's not free/next to free like the guy tuning mine will be). So basically everything could be done at one place.

Let me know
Matt

 

yeah I am interested.
I am mainly looking for someone who would be willing to work with me and build the headers, do the piping to the intake/intercooler, and make down pipes and possibly the exhuast out the back.

As for everything else, I would take care of it myself as well (turbos/intercooler/electronics/fuel system).

Great news.
:cheers:

Also wondering, do you think this guy would be upto modding a stealth ram to fit under the hood of a vette?


[Modified by bill mcdonald, 12:48 AM 8/27/2002]

 

Well, hes told me he's willing to do anything basically, he enjoys the challange of stuff.

I will get his number for you this week.
:)

 

$3500 for a custom twin turbo setup, including intercooler! That sounds too good to be true. Is that just labor?

I wish I had know someone willing to work that cheap last winter....

9.0 should be considered the max static compressionr atio if you wnat to run more than 6-8 psi of boost, and you do. My engine is 8.5 CR, and on 93 octane I made 1189hp and 998 ft lbs with two 60-1's, on 18psi of intercooled boost. The tune was pretty conservative at only 23.5 degrees and 11.7 A/F.


[Modified by Monty, 10:38 AM 8/27/2002]

 

Its the labor and parts. He makes his own IC's out of cores, and makes his own pipes out of 180's. He said it would be about $3k with T03's and about $3500 with T04s, so I assume the part difference is the extra cost, I cant see that it would take more labor to do them...

With a motor like that I assume you know your poopie rather well. Is there a way I can drop compression? Assuming I can get 74-76cc heads (anyone make bigger?) to drop me to 8.7-9:1. Can the bowls be ported, thick head gasket, etc?

What turbos would you recomend? Scat says the crank can handle 600hp.

What block did you use for your build up? And what crank? Scat said they have billet cranks that can handle over 1500hp. Maybe I could build another motor on stand for the TT setup ;)

Anyways... opinions?
Thanks
Matt

 

This would be best, build another motor with blower/turbo pistons. and forged rods

I think the scat crank would hold up tp 600 hp. There were some LT1 guys making 600 with a blower (545rwhp) and using the stock crank. I think the supercharger would be harder on the crank then turbos.

You dont want to go to a thicker gasket on a FI motor to get the compression down.

If you really want to push it like Monty is, I would go all out on the short block.

 

Matt, thats an incredible price. I had a custom intercooler made, and the Spearco core alone was $800. Materials like flanges and u-bends from SPD and Burn's were another $1500+, although I used all 321 stainless steel. Even if you were getting them made from cast iron weld-el's, that's a crazy low price, but if that's what he charges I wouldn't tell him that. I called several shops to get estimates and they were all between $10,000 and $15,000.

What pistons are you using, and are they designed for forced induction or nitrous. Pistons designed for this will have the top ring further down, usually .300" or more, and will have thicker crowns, as well as being made from a different alloy. You can get a set of SPD's for around $450. Also, you might want to consider running a set of stainless steel top rings. If you did get new pistons, you could get them with the appropriate sized dish and you wouldn't need to swap cylinder heads, unless you also want some better flowing heads. Contrary to popular belief, good flowing cylinder ehads are just as important on forced induction engines. They will make more power with less boost.

I jsut think that if you're going to go through the cost an effort of designing and building a custom twin turbo setup, you should do it right and ensure the engine is ready for it. Adding any power adder can magnify and preexisting engine conditions such as worns rings or bearings. A fresh hone and a new set of rings would be my minimum recommendation.

Most turbo's are based off of Garrett's, or sometimes AirResearch, Rajay, etc. Any of the more well know turbo shops will set you up with what you need - Turbonetics, Precision Turbo, Innovative, etc. I'm just running two small 60mm's, and they are rated for 600hp each. Choosing a turbo is just a matter of determining you airflow requirements based on engine displacement, rpm range, and power goals.

As far as cranks, remember that rpm breaks parts, not boost (unless you detonate). It depends on how much power you want - 1000hp is no problem. It may seem like alot, but with forced induction pretty much anything is possible.

I used a Dart Iron Eagle/Rocket block, with a Crower billet Ultralight crank. I don't think an aftermarket block is necessary until you get into to 700-800hp range. Also a billet isn't necessary, I just got a good deal on it. A good aftermarket 4340 crank is plenty. I know some guys in NMCA/NSCA that make almost 2000hp and they use a forged Scat.

Good luck! Once you go turbo, you'll never want to drive anything else!



[Modified by Monty, 7:19 PM 8/27/2002]

 

They are JE/SRP pistons, for a 383 with 6" rods. It doesnt say they are for forced induction. Right now the motor is sitting unfired still, so there shouldnt be any bad parts ;).

So your thinking that the crank I have should be ok to crank some serious HP as long as I keep the RPMs down? (I wouldnt want 1000hp daily on the street, but custom tuning can put it there when needed).

As for the money thing... I am thinking that for the price, I could run lower power, being easy on the system untill I could build a motor stout enough to crank 1k steady. Kind of a get it while I can at that price thing. If I were to start from scratch on a new motor with plans to go twin turbo with it, I dont know what i would ever make it, I have other hobbies and saving money is hard for me sometimes.

The guy seems to be resonable on stuff, he seems to be a hobbiest as opposed to a money greedy shop owner like alot of places out there..

Matt

 

Sorry I meant SRP when I said SPD above - not paying attention I guess.

I would hesitate to use it if you're going to stick to 6000-6500rpm and 600hp or so. More power than that, and more rpm than that, and I'd say definitely go for a forged 4340 crank. This is assuming you're sticking to a 3.75" stroke. If you get up to 3.875+ and still want to maintain a 6000-6500rpm range, I'd say go forged also, as the piston speed is higher with the longer stroke. It sounds liek you just want to get started and then possibly build a more purpose built motor later on. As long as you keep the rpm and boost down to the levels you're mentioning, and your tune is conservative and safe you should be fine.

Good luck!

 

Monty
Do you know of any shop that will custom fabricate Twin turbo for LT1 vette? I don;t care if I have to get rid of the AC or the ASR unit for space to install turbo. I am thinking down the road I am going to swap to twin turbo. I curently running ATI D1-SC Procharger. And I am not happy with it. Due to mainly is limited to boost and belt slipage. The ATI drive belt system is sucks. Its a serpentine type. And it cannot be convert to 8 rib setup because blower bracket and everything else are on the way. Only Vortech blower can do 8 rib conversion. The reason I want to swap to turbo charging is that, my motor was built for forced induction already with all forged internals and heavy duty blower JE pistons and JE rings. So all I have to do is have a shop to fabricate the kit for it. Monty, at what price range do you think it will cost? for TT fabricate and install alone on
LT1 vette. Thanks

Bruce
93LT1 Conv w/ZF6
Blown D1-SC/N2O
ARE built 383ci/Stage II heads


[Modified by Bruce, 11:49 PM 8/30/2002]


[Modified by Bruce, 11:51 PM 8/30/2002]

 

There are plenty of shops that will custom fabricate twin turbo setups, the fact that it's an LT1 shouldn't matter. I would be prepared to hear estimates fo a complete TT setup, including an intercooler for $10,000, depending on the materials you use. It's definitely alot of money but it's time consuming, easily taking 50+ hours

 

Thanks Monty.

Maybe that some thing I have to look into down the road. I already have spent well over 14k on my blower/motor setup. Maybe I have to dump another 10k to get me happy.


Bruce

 

For moderate power (till 15PSI) 383:

Rajay:
2-301E70 (rec. for 350)
or
2-301E80 (rec,. for 400)

Roto-Master T04B
Trim | Turbine A/R
2-(S-4) O-.81 (for 350)
2-(S-4) O-.96 (for 400)

Marck