Tyler Townsley

EvanZR1

Yes, 152MPH in the 1/2. And I just looked at it, it was actually 177MPH in the Mile.

Agreed, Pete did my 391 at 12:1, so even though it's closed deck and forged, I definitely wouldn't boost it. Would have to drop back to lower compression if I wanted to. I'm pretty sure I remember seeing some TX Mile speeds from a Corey Henderson built TT ZR-1, think it was like 200MPH in the 1/2 and 250MPH in the Mile. Don't want to know how much that cost, had to be stupid money.

vermatrix

according to the procharger catalog 1992-95 (LT1) 1GF211-SCI High Output Intercooled System with P-1SC (satin finish) 8 psi 55-60% LT1 Vette 2 core $5,998

so that should yield 465 to 480 HP with the stock LT1.

Dominic Sorresso

That’s why I asked. Should be able to easily reach that kind of power w top end porting and headers on an LT-5, and NA.
If u are a DIYr, should be pretty inexpensive.

Rkreigh

will ruined me for the LSV with one ride That car was "within reach" and I missed it

the callaway and LPE TT ZR-1 are just SOOOO nice

I think with e85 as the secret sauce an 11-1 zr-1 would do just fine on higher boost. Wayne did some "race gas" tunes on the stock block tt SGC car and got very good results

i'd bet a mild tt on e85 with mls HG (pull the heads to soften the combution chambers) with MLS hg (this will raise CR, which must be considered) would do quite well

the stock lt5 is very strong and as long as detonation is 100 % avoided which is easier to do with e85 a stock block would live just fine if you don't get too greedy


as for a 380 build it's an offset grind stock crank, liners are 1000-1300 if you shop around, and you can get away with an intake set of cames and pete's magic on the porting and be quite happy with around 500 or so at the tire

at that level with 410 gears, you are at the limit of reasonable street tires and will have a long lasting combo that puts down as much spank as the old 385 cars did (with less aggressive porting back in the day)


I am convinced that hacking up a stock set of 93 95 exh manifolds (*v band *) and positioning the turbos like the ttix kits do on the c5 with modern small frame turbos that provide plenty of cfm min flow to feed 1000+ hp works just fine

the big v8 will spool a reasonable turbo very quickly and then the problem is back to traction and zero to jail happens very quickly.


Again, boost shines there, with the right tuning you can vary the low end boost with boost by speed and run flex fuel with the after market ecm.

if really on a budget, the stock memcal can be burned for e85 and you could easily carry a "pump gas tune" and just not run much boost at all when e85 isn't available

one thing we discussed that I think would help is some 4.0 closed deck liners. costs goes way up but it presents a more stable deck without reaming out the liner register which is thin already.

I hope to have the $ to build one, I been lusting for one for so long I got tired of waiting an bought a turn key turbo c5 ttix

that "proof of concept" makes me want the tt z even more and will's one ride was all it took.

Tyler Townsley

Here is a gt 500 sc on my lightning engine Fairlane. If you look close you can see an adapter under the sc which allowed me to put the mustang sc on the lightning 5.4. Since it has the rear tb it seems to me someone could take the lt 5 plenum and adapt the sc to the motor. Hood clearance will be a problem but it would sure be a whole lot easier than all the pluming associated with the turbos.

Rkreigh

the lsa supercharger fits the valley like it's made for it and puts out plenty of flow for 800+ hp

move the coils to coil on plug with a ms3 pro, and figure out the drive assembly and a supercharged lt5 is a reality

randy did the 600 hp small rotex deal and I've seen the dual rotex which was on a SB chevy by wheel to wheel that put out plenty

the turbo and intercooler plumbing is not at all trivial, but it's much cheaper to do than it was back in the day. The modern turbos are quite a bit better too.

engines don't care how you give them flow and cyl pressure, and I would love to see a few more boosted lt5s

cv67

Vermatrix, the 350 LT engine and LT5 have pretty much nothing in common. They cost a LOT to build up, your local speed shop wont know what to do with it.
Owning or modding a Z requires more of a $$ commitment to own, ya gotta really like them. Good news is they are tough to break

zrc3john

Buy a nice looking C-4 corvette...You can pick up a nice one for 6-8 thousand..Just mod the crap out of that one......

Turbo charging, super charging an LT-5....??? I'm guessing by the time your done you can buy a second ZR-1 for that price.....

EvanZR1

I could have almost bought another ZR-1 for what my 391 engine build cost. Those of us doing mods on ZR-1s don't do it because it's cost effective, it's more a matter of loving the car. Either that or we've lost our minds.

Dominic Sorresso

Well said Evan. One thing that I would want to correct is this concept that 400hp = 400hp. Its not! 400hp in an LT5 is not your 400hp in your LTsomething else. Typical modded SBCs are going to peak in the low 5K rpm range.Modified LT5 peaks at ~6800-7000rpm. Once at peak, power drop off in an LT5 is very small. An OHV SBC power drop off looks like it goes off a cliff. At "equal" power levels, the DOHC is going to be more tractable for street driving since its not necessary to use radical camshaft profiles for deep breathing at the top.
Its a different driving experience period. I know GM tried to convince people that the LT4 was "almost" like the LT5, but it really wasn't. What u get w the LT5 is just a sense that the motor will never stop pulling and that it continues to accelerate way past the point of where your SBC was already nosing over. Sometimes it feels as if the car is driving away from you at top end.

EvanZR1

Very good point, the LT5 just keeps pulling forever, and if you haven't driven one before, you're going to shift WAY too early. I've had three 90s LT1/4 engines (both stock and modded), and none of them pull like the LT5. With a medium cam they'll probably peak at 5600-5700, and with a monster cam maybe at 6000. Plus as mentioned they all nose over pretty abruptly. My 391 LT5 with stage 2 cams pulls hard all the way to the 7400rpm rev limit. Drove it to lunch Saturday after not driving it for a few weeks, and getting on it a couple times I kept thinking it was time to shift when I still had plenty left, mainly because I'm used to my daily driver C7. Luckily I have a shift light to help with that so I can just keep my foot in it until it lights up.

Dredgeguy

What do you have your shift light set to?

EvanZR1

7300. It's pretty obnoxious: Raptor shift light mounted in right hand AC vent pointing directly at my face, so when it goes off, I immediately shift.

zrc3john

Where did you get the shift light? Summit?

EvanZR1

Raptor Performance shift light

Dominic Sorresso

Mine is set to 7200 w fuel cutoff at 7400

cv67

[QUOTEWhat u get w the LT5 is just a sense that the motor will never stop pulling and that it continues to accelerate way past the point of where your SBC was already nosing over][/QUOTE]
Agree, yet many will overlay dyno sheets trying to convince themselves they got :the same thing" it simply isnt, cant be period. 2 different animals. the 4 valve dohc imo is superior.
Sometimes wonder if lots of these older LT5 cams have too much duration/overported parts and can make more with less.

Dominic Sorresso

"Sometimes wonder if lots of these older LT5 cams have too much duration/overported parts and can make more with less."

Not certain what u mean by that. For the most part, we have modded LT5s that demonstrate the performance of porting and adding "more cam". Having said that, its been demonstrated that the stock exhaust cam or a smaller modded cam may be sufficient. The exhaust of the stock LT5 is pretty efficient and needs little help even w bigger CID motors. Large exhaust cams may actually be counterproductive in terms of making power.
I am certain that Todd can provide significant insight to this due to his extensive experience w cams and larger CID motors.

Rkreigh

Agree, yet many will overlay dyno sheets trying to convince themselves they got :the same thing" it simply isnt, cant be period. 2 different animals. the 4 valve dohc imo is superior.
Sometimes wonder if lots of these older LT5 cams have too much duration/overported parts and can make more with less.[/QUOTE]

if you go max porting on a stock displacement motor it still makes gobs of power. the ports are small volume and high velocity

these motors don't need super high lift radical cams to make power. In fact, many use the stock exh cam and do quite well