solid dobe

naturally aspirated LT5s have been built up to around 600hp. Maybe more, IDK. I am sure that the C3 big blocks can be built up to more without resorting to turbos or superchargers.
However, I do wonder what the C5, C6, & C7 naturally aspirated engines are capable of being built up to without resorting to nitrous, Turbos or Superchargers....while still being reasonably dependable? This may be common knowledge but I do not know.

How does the LT5 stack up against later engines as far as attainable, livable Horsepower? I know the expense, I wonder about possibilities.

Rkreigh

fast lane went to 900 NA with a radical 421 stroker "the hard way"

LPE TT cars were over 1000

both these setups are bank breakers the LPE was 53k

Todd I believe is over 700

I think franks car was 660+ or so at the tire with the haibeck 441

it's not the HP, it's the durability that makes the LT5 an amazing engine

but much over 500 at the tire becomes academic on the street as most tires have a hard time hooking that

ask me how I know

Dominic Sorresso

We have 5.7L LT-5s w 540-560 chp. 427 to 441 CID making 700hp. The difference between them and LSX type motors is that a 4 cam can make that power and idle while not sounding like a bathtub being drained of water. Glug, glug, glug.

ZR-71

FU

While I like the LT5 esp. a very well modded one.
I'm going to say that Id love to mount a LS engine in a ZR1. Lose an easy 200+ lbs off the nose and those LS engines are just soooo damn nice.

oldpro

hate to say it but have to agree the ls motor is sweet . I have diven bill boudreaus ls conversion and I runs pretty strong . and doesn't even have headers .. bill and I have talked about putting a ls3 with a little 5lb supercharger on it . leave the exhaust stk and what a sleeper . but it is so much fun to open the hood at the gas station . peoples jaw drops when they see the lt5.

mike100

If I drove over my crankshaft tomorrow, I considered an LS3 with LS7 manifolds and a tune- too bad only the 89 and below cars dash integrates better with an LS conversion. Hooking up a ZR-1 with a Ford Coyote might be a better philosophical replacement if you can get past the blue oval part of the deal.

oldpro

putting in coyote motor in zr1 the car would develope a serious mental problem and a rash to .lol

Rkreigh

why not? it will likely fit and stock they are at 440 with lots of potential!

cheap too. I know it's not going to make the purists happy but HP to me is more important than the brand name.

if Ford made a better bang for the buck than the vette, I'd be in one.

the new mustang is a pretty nice car now.

Dominic Sorresso

I think my choice for an experiment would be to use an LSx block with a set of Mercury Marine DOHC cylinder heads.

ZROne

I have a new GT. The car is really reminiscent of a stock ZR1 because of that motor and the IRS ... even runs the same trap speeds as my '90 did (but quicker because auto). The huge difference is of course aftermarket support and room in the engine bay, plus I had no idea when I bought it that the motor would support enough power to push into the low 10's/high 9's with one mod (oil gears).

Hopefully though my '94's LT5 lasts a long long time since it still sounds better than the Coyote and can't be beat on coolness.

5abivt

This is interesting stuff ! I LOL @ the bathtub comment !!!

That is precisely the difference. I have a 614 engine dynoed 370ci LT4 going in my 93. After breakin and tuning im hoping 620+ In order to make that power ALOT had to be sacrificed. It idles at 1200, 5th and 6th gear unuseable as it has a weak midrange as it was cammed for 8500 rpm. Its basically a radical toy that I cant really enjoy for longer drives or dd friendly tasks.

Its the single cam and its limits. Its the reason factory cars gain more with mods with a single cam because the oem cam has to do it all. pass emissions, make torque and power (or try because oem cams blow). Wit the LS7 they stuffed it with huge displacement and tried to rpm a little to make the hp goals with the oem cam. Because of the displacement and heads though.. its no wonder they are easily 100+ hp with cam swaps.

I have an LS6 in my ctsv and its smooth and torque and just dies of breath above 6000. Its a tow truck motor in my eyes. Im not hating on the LSx but its not a special motor. I don't even want to beat on it too much because it doesn't sound awesome nor make any special noises or rev hard top end.

I really like the idea of the coyote swap. Anyone know how realistic it might be in our cars? because of parts availability and cost I would definitely consider a build and maybe even do a custom billet manifold to look like the LT5

SAM/CH ZR-1

The LT5 has alot of power potential. The intake (plenum, injector housings) with its turns is a restrictor.

The racing team I do consult put straight single ports on their 350 cui LT5. The engine pulled on the dyno 565 crank hp at 7'100 rpm with 50% open trottles and 675 crank hp at 8'000 rpm and still didn't hit the power peak. Due to durability purposes they didn't turn further. The idling is by arround 1'100 rpm.

The motivation and challenge is to build a bridge between smooth idling and normal driveability and a high power output at WOT.

We calculated and found out a 427 with straight ports, fit cams, a good exhaust system and other goodies can pull +800 crank hp and can be even roadworthy.

1993C4LT1

Are you going to start a build thread on the 93? I love the LT5 engine, I need to get me a ZR-1 one day

Rkreigh

looking to see if an obx ITB could be adapted to the lt5 with some sheet metal fabbed up base. concerned about the impact of low speed throttle response and ability to tune for the street.

I have a idea that the LSV 390 would jump from 619 to around 650 and pull much stronger up top. I need a bit more head porting too.

let me know if you are interested Sam in exploring this or have a similar solution. ITBs on an LT5 would really be cool.

Dominic Sorresso

Sam,

How does the race team u consult for deal w the cooling issue at high rpms?

SAM/CH ZR-1

Ron
The OBX individual trottle body could be a interesting base. The custom made ITB the racing team did, cost alot (about Euro 14'000) and sacrifice the A/C compressor. I want to avoid that for other engines because as told the LT5 shall be useable for daily driving.
Many challenges must be solved to make it work and it's a question of time and financial resources.
Another option is to build a completely new plenum with another port design.
Whatever, I am interested.

Sam

SAM/CH ZR-1

Dominic
The engine run with a electric water pump.

Rkreigh

a few hogans intakes and bill k built a custom intake I haven't hear that they were all that successful the stock intake takes a rather torturous path and the injector housings are restrictive

I'd like to retain AC though, that would be a deal breaker

maybe something along the lines of the new intake on the prototype MY 95 intake would work well

I think the factory intake might be leaving 30 or more hp on the table

SAM/CH ZR-1

Should we maybe open here or in the ZR-1 NetRegistry a new thread about LT5 tuning possibilities and findings?

Sam