Anyone ever thought of doing a full built motor with 11.1 compression and a twin turbo setup? I see everyone that gets a fully built motor goes with low compression to turn boost up. If you had a higher compression and low boost wouldn't it be the same as turn boost up? It's just a thought since the 370z is defying what people what is impossible. Any thoughts

 

What are your intentions for the car? If building a motor, assuming pump gas, you will make more power with increased boost on lower cr than you would with increased cr and minimal boost.

Now, if you can afford some good gas... go for it!

PS. There are a lot of variables that go into this, such as turbo efficiencies. You should take as much into consideration as possible when making your decision.

 

If you decide to go for more power the only way to do it would be to run Race gas that's why most go with a lower compression to get higher numbers on pump gas but make the turbo's work harder

 

Detonation.

 

Thanks Hal
I was just aiming towards around 430-470 hp as a dd and thought it would have a pretty good torque curve with the high compression. Would 11.1 cr be too much to run on reg pump gas just as a na? I aslo figured it'll be less stress on the turbo since they won't have to work as hard. I guess reading up on tt 370z was making me wonder if that same aspect could be done on a de motor. Would a supercharger be more efficiency then a turbo?

 

I see what your saying about having the turbo work harder that's why I was thinking if you went with a higher compression it would elevate the turbo workng so hard

 

1 cr point will only equate to around 10hp all things being even. 1lb of boost can be as much as 30hp.

But like Hal said, dropping cr a few point allows you to run a lot more boost safely.

tom

 

I see what your saying Tom just thought since it wasn't going up a full compression it wouldn't be that much of a different just be safer on the turbos then the block since they won't work as hard so it'll be efficient

 

OP, just one thought to throw out there... A lot of us started with pretty moderate HP expectations but, once we boosted, we wanted a lot more. Boost is addictive! With an 11.1 CR, you will be pretty limited on how far you can go on pump gas. Just keep that in mind. If you will be fine with the stated hp level long term, or you don't mind running race gas all of the time, then the extra CR will help your efficiency a bit.

Another avenue to look at is E85. The nearest station to me that sells E85 is still too far away, but if you have one close to you, then perhaps that is a cost effective way to go.

Another thing to consider is getting small turbos. For your stated HP goals, there are kits out there that will spool up fairly quick. I have seen some of the smaller turbos give a whole lot of boost down around 2500 rpm. That way, you can run lower compression on pump gas and still get wicked low end torque. And, if you ever decide that you want to go big, you will have the option to do so by merely getting bigger turbos. With some kits there may be further changes that are required, but other kits seem to be fairly universal.

 

thinking its a great idea!

 

 

OP, I have thought about doing the same thing with my STS(I wish it was TT but stuck with what I have for now.) With the ceiling that my kit has I have wondered the advantages.


I have also thought about the E85. Wondered how effective it is as a substitute for racing fuel when running higher compression.

 

The only major problems I see with the higher compression is increased cylinder pressure and temperatures.

 

Let's see how long these TT 370's last first and if people are actually seeing boost more so then just having a high hp dyno queen to model in parking lots and interwebs. With a conservative tune and running on wastegate pressure they should hold up but i find it hard to believe that 370's can make GTR power and last like some members have inquired.

 

I agree, but I think the vvti is what's making the whole tt setup possible. It's not like we built tt motors to last us forever. Then numbers are low on the gtr because of the slippage in the transmission. If you read the d-sport with two gtr on front you'll see they have problems with it not changing gears and some other things. I'm surprised no one decided to do what blitz did and turned it into a rear wheels drive with a 6 speed. I really hope the z's don't become the new face of the dyno queen like the supra are it'll be a shame.

 

IMHO supra's have become known to be dyno queens because they are heavy and rare so i'm not heart broken . But the Z IMHO was made to drive and drive hard. And as Berto has asked time and time again, are people really driving these cars or are they cruising rarely seeing the boost they paid for? I did notice all the ancillaries on some of of the newer builds from GTM and AAM so i guess time will tell but jeez 500+ HP on a NA spec motor?

 

My car rarely sees less than 550+rwhp. ITs a toy, was built as a toy. I am in boost OFTEN

tom

 

^^ wait hold on, a Thom post with no reference to his powerband falling flat after 6000 rpms because of his stock cams?

It must be a Xmas miracle LOL

 

Ha, but its truuuuuuuuuuueeeeeeeeee

(and it doesn't fall flat, it falls off lol)

Merry Christmas to all, and to all a good night!!!!!

Tom

 

To the OP, I have a GTO twin turbo'ed LS2 motor with 11 to 1 CR. I'm running 7.5 psi boost on premium gas. It spools up fast. I know that comparing the LS2 to the VQ is like apples and oranges, but I think you could build a similiar setup with your motor, and would make an incredibly quick street rod. You will be giving up a lot of peak horsepower/torque numbers but have a nice flat torque curve from 2K rpms to redline. ( PS I wanted to run 10 to 1 on my VQ4.2DE, but my engine builder talked me into 9.5 to 1 CR on my Z)