First, just because I'm a moderator, doesn't mean I can't voice my opinion here, even if it's 100% biased. I was a member here for 12+ years before becoming a moderator, so being a mod means nothing when it comes to voicing my opinion about a setup....

Now re-read what I wrote. I didn't say that a turbo can't do what he wants, but what he wants is a linear power band like a big block would give him. If you look at the way a procharger makes power, it's a gradual, linear power curve, and has been compared to adding more cubes to a motor countless times, which I agree with. My car is setup for corner carving and blasting through the twisties. I have Koni's, strano springs, 19's front and rear, big breaks up front, toyo R888s, it's setup for doing what the poster wants to do. So I have first hand knowledge of how predictable the car is.

Now, re-read what I wrote, can he get a turbo to do that, sure, but it's not as simple as doing a procharger is. You've got to do a boost controller, and you will have to get it to mimic the boost curve of a procharger to where the power comes in more gradual and linearly. So now, not only does he have to buy the extra items, he also has to figure out how to tune it properly, or take it to someone and have them tune it for him, again, adding in the expense.

As mentioned, the last thing you want when powering through a turn is for the power delivery to be abrupt or unpredictable.

Can he do it with a turbo, sure, is it going to be simpler to do a procharger, yes, and that was my point.

If you're upset that I gave my opinion, even if it's biased, then you need to step back away from the computer. I wouldn't hesitate to say the same thing in person as I do on here.

 

The OP bailed out of the thread 6 months ago, recent queries were from Snow Dog requesting power/torque from 2-6k.

A centri setup will not do what he has asked.

 

See, I'll agree to disagree with that. Look at my dyno graph. From 2500-5000rpm, I go from 400ft/lbs to 700ft/lbs in a nice, linear fashion. It's nearly a straight line in that range. Ok, it levels off and starts to drop after 5,000, but that's because I had boost leak, and a NA cam in the car.

Still, at 2,000rpm, I make just shy of 400ft/lbs of torque, so it's not like there isn't power available down low.

Granted, he's an LT1, so it will be slightly different.

No doubt a turbo setup can be optimized to make him happy, but can it be done with a centri-blower setup (not just a Procharger), I think so.

 

A linear power delivery, isnt a delivery with a lot of torque from 2k.

Ive had 346, 382, 403 in my car, at various times and sometimes back and forward between sizes, almost all with the YSi making a lot more than 700 overall.

None I would say excel at 2000rpm. The difference in torque between the different engine sizes is quite marked, and when cruising, lazing about, the larger motors are actually quite welcome.
The YSi wasnt making any boost by that stage despite spinning it very hard, but it is still contributing to performance. I can say that for sure after removing the YSi on my own car and running n/a and now with two turbos. Although they certainly arent sized to make boost at 2k.

Going from even the 382 back a 346...down low the smaller motor really did feel tame. Top end ? not a lot of difference really.

So I can say with 100% certainly no centri will never compare to what a turbo setup will feel like if it is designed to be making usable boost at 2000rpm. It's just impossible.
And even more so if that centri build is geared overall to be only making say 600hp, it would be contributing very little air at low rpm's

I'm not saying a centri equipped car wont feel good, because Ive no doubt it will, but the torque will not be there.

So a lot will depend on driving style. My YSi on any of the above engine capacities, always spun pretty much the same speeds never really came alive til around 4500, then it was quite aggressive and felt superb. I'm not saying it was dead below this, it wasnt, but above that the feeling was far more pronounced.

Contrary to the above, yes you can do a lot. But if the turbos are not sized to spool at say below 3000rpm, then there is something you cannot do. No amount of boost control trickery will make them spool below 3k in a manner they can be used for daily use. So you still need to size the turbos for the job in hand. Then you have much flexibility with what you can do, what sort of power delivery they offer.

But it will all boil down to driving style, vehicle weight and usage, gearing etc etc

Some people love low rpm torque, some love a more revvy approach. Some vehicles simply dictate low rpm torque, etc etc.

 

My signature says it all for me! I just love the responsiveness of the blower. There is pros and cons of each!

 

I certainly wont argue with that. The instant response does feel superb.

 

Interesting. Are the boost controllers stand alone or do they interface with an ECU?

I appreciate the replies everyone.

 

Well, I step back to the two of your experiences, you've definitely had far more FI experiences that I have. I can only refer to my own personal experiences with my setup, and I love it. Now that's not to say down the road, I won't try a small to medium turbo setup, just to try something different.

Fact is, when I'm out driving for enjoyment, and carving corners, I keep the rpms around 3,000 to 5,500 and the throttle response is phenomenal and predictable. Maybe the turbo is the same, but I doubt it.

 

Most aftermarket electronic boost controllers in no way interact with the engine ecu.

IMO the best overall package, is where the ecu controls boost. Obviously this will require an aftermarket ecu to give you that.

And as with standalone boost controllers, boost control offerings on aftermarket ecu's are certainly not all created equal either.

 

Crap! I'm acting like a message board newbie. I completely missed that the replies had reached the fourth page.

I do appreciate the feedback and discussion everyone. It's all very good info as far as I'm concerned. I wish I had been able to keep up with all the tech changes through the years. I feel so behind and out of the loop.

 

If you built the turbo setup to spool and offer full boost at any point in that range, then it too would feel awesome. Still not as lightning sharp as a blower, but still awesome, and because of the small turbos, spool, boost recovery after a gearchange etc would still be very sharp.
But if it was built to offer "full" boost by 3000rpm, or even good usable boost from 2000rpm....clearly it would have a huge advantage over the centri, provided that power can be put to the ground.

Even a baby 10psi from 3k to 6k would yield more power/torque overall than a centri only making 10psi at the top end.

Again, depends on usage, depends on vehicle weight, transmission etc etc.

The two vehicles will feel very different, they can be driven very differently, but both would still impress I'm sure.

 

That's a big reason I'm only shooting for mid 400s. I only have a 9.5 tire under the car now. Maybe one day I will mintub but I simply don't know. Not only that, but, in all honesty, I enjoy driving and playing with a car that has sub 500 to the wheels on the street. Anything more and it's no fun because the fun has to end so soon or you become a menace to everyone else on the road. So my focus is on having enough power to get my 2nd gen moving quickly in a wide range of situations.

 

First, I never said that you can't voice your 100% biased opinion. So, don't be too sensitive, I'm just simply expressing my opinion just like you do, that is...if I'm still allowed. And secondly, I'm not upset. I just happen to think that it's kind'a ridiculous that even though you admit that you personally have not driven an LS turbo car, or for that matter, a properly set-up turbo car for that same roadrace application, and yet you give advice as if you really knew based from experience on both applications. Again, the fact that you lack experience from even driving one is what I find upsetting, oh! I meant....ridiculous.

 

Didnt think the goals were that low.

Just buy a crate 427 LS or something along those lines, that will easily exceed your goals, and be totally simple and reliable n/a

 

Dont think you cant get more power to ground.. I had very little traction problems at 700+hp/700+tq when i ran a similiar size tire. First gear was the only problem, after that it was all good.

 

for mid 400's go heads/cam and bolt ons will get you 450+

 

Honestly, the only reason I'm wanting to, or considering, sticking with the LT1 is because I have it and to simply be different. A stroker LQ or LS2 would be more than plenty of power and torque for me. I may still consider swapping out the LT1 but we will see.

Thanks

 

Ah Lt1 then add a 75 shot of nitrous to the heads/cam and bolt ons.