Lets play the what if game....

Gary's car has been 9.97 with shelf bolt-ons and some bad *** driving..... And he is 0.004 faster than the internal mods guys in the C6Z section.....now, what if he took Robz 's approach to the NA internal mod title ??

Kind of like this.......

427", milled stock heads (based on dcr of cam and ptv), flycut, ITB, custom ground cam and valvetrain, F/P 6060, slipper ( Hyatt, Advanced, McLeod, Bonifonte), 4.10, evp or bdvp, ewp, Matt T&T tune, pull some weight out....just the typical extras (seat..etc)...all of this on a brisk winter day at Atco or MIR and of course on radials...???

Could we see a 8.99999 @ ???

I understand he has some of these parts on the car already. And I'm unsure of the rpm capabilities of the sbe 427 ?? Also, the tire rollout combined with the gear may need to be addressed and pcm rpm capabilities ??

Or is this very unrealistic ?? I would think that his driving ability coupled with the great tracks in that area plus the altitude and weather patterns it would be a possibility. And that crews attention to detail !!!! I'm thinking a sbe C6Z could go 8.9999....maybe I'm wrong.

But I would love to see it.....

 

Sounds like Robz vs Gary, run what ya brung

 

I would think the LS7 would not need to be turned like Robz 388 to make the hp/tq number. There for the rpm issues maybe aleaviated...maybe. Really all depends on the valve events and induction ideology for filling the used/avalible mcsa/volume.
The LS7 with a complimenting bumpstick and matched induction system should be north of 575rwhp and north of 500rwtq (Im talking pump gas build). Plus the tq curve would probably look like the Colorado Grand Mesa Plateau......


Its just money.......and you only live once...... And.....remember...pain (money) is temporary but pride lasts forever !! Think of all the butt hurt individuals that would be crawling out of the wood work !!

Just like pittman said....run whatcha brung...and hope you brought enough. We will call it a drivers race....


Gary....your thoughts ??

Thanks....

 

I think Gary is already at 520 and Rob over 6 and short shifting. Gary will need the perfect cam and milled heads to get near 6

 

I think your numbers are pretty low for a max tune LS7 setup. I would expect more towards 620RW if you don't care how it drives.

 

I think your right....lol. Not sure what I was thinking.....the numbers would be more like 620+rwhp/525+rwtq.......

With ve being 1.6 per cube/hp and 1.3 per cube/tq.....which is very do-able with the LS cylinder heads and an ITB.....

Come on Gary....tilt the world off its axis with a 8.99999 with a sbe LS7............and an IRS to boot.

And watch the whiners show up in droves.....




Thanks............

 

Its the end of the world anyway....so the Mayans say.........

Go out with bang....and very big bang...........just make sure its before Dec 21st...lol

Darrin has the head program your after....if you think it will take more than 270cc to get it done. Lots of magic in the short side and seats. And IMO, very reasonably priced.

http://www.darinmorgan.com/dmch.html

http://www.rehermorrison.com/rmSale3.htm



Thanks..............

 

I think this would be Very badass. Something I'd like to do if I had a c6z.

 

For most to run that fast it's going to take more than 800rwhp and everything working optimally in a c6Z. The powerband will need to be optimized as well for drag strip. I can think of so many things that need to be done right to even approach that.
Some cars struggle to get into the nines with 800+rwhp. It's not easy.

 

No. Not with the above.

 

Thanks for joining the conversation Rob. Hope you like bench racing....lol. The air sucks right now so this is the next best thing..

Well, we can throw out putting 800 to the tire with a sbe 427 raw.....2.1 per cube on MON, RON or PON is crazy talk...IMO. I could see 1.7/1.35 on PON.

So......that means the combo will need to make it up elsewhere.....

Weight....sub 3K w/driver ?? Worth ?? possibly 0.06-0.13...not sure how light he was for his 9.97.....the weight removal could possibly be worth more depending.

Eliminating the 2-3, 3-4 shift ?? Worth ?? possibly 0.07-0.15.....I know Gary shifts very fast but I've yet to see a datalog with his "time".

ITB vs FAST LS7 ?? The ITB has been know to put 100%+ VE with the correct guy tuning it. Worth ?? possibly 0.05-0.15...very hard to quantify.......My only question is....is the ITB's "clean" air (lacking the waves/pulse degradation) worth more than the "ram" effect of other CA systems without the filter, mated to a FAST (102kpa+) ?? I question the lack of cold & ram air with the ITB ??
And possibly the increased rpm capability of the ITB would be a nice advantage....

LS7 heads.....rolled 1.5* (10.5 VA) combined with a custom runner/chamber/seat program along with a quality shaft setup. And of course keeping the mass as low as the budget allows.

And as you alluded to, the optimized powerband will be a huge factor and would love to hear your thoughts on the subject. Shift recovery, rpm drop, custom trans gear ratio selection etc..etc.


So Rob....since you have lived this.....what would you say a combo like this would be worth ?? 670whp/570wtq @ 3K w/driver with all the details described and some I have not ??



Thanks...........

 

In general terms...

I'm sure everyone thinking street car but 8's and n/a street car just don't jive.
I would imagine 650+rwhp is going to be the limit for something that you can call very streetable without some sort of ITB or other design that we currently have available.


Quick word on ITB.
The current ones available to even consider bolting down to a vette without major reconstruction have inherent problems.

1) Runner length adjustability-ideally you want to dial that in. Very hard to do unless you can fabricate and have alot of r&d that no company is willing to do.

2) If you want filtration you will have to pay the power penalty and make some custom setup. I ran filter socks on street and open on the track.

3) Heat and closed hood. Perhaps most important. Without fresh cold air these systems struggle. They dyno great but on the track something needs to be made to direct fresh cold air to the trumpets in a confined space. Ideally you want some type of heat shields and air box combo to get the true performance on a track. That also means some sort of open hood or ram air system. I actually designed and made custom air boxes and mated them to a custom hood. We saw some gains but without the use of a wind tunnel we were unable get it all working optimally. I would expect to gain a few tenths and 5 mph
when designed correctly.

4) Trumpet diameter. The ideal diameter just doesn't fit in many dimensions for the type of motor necessary.

5) Difficulty in tuning manually and via computer software. I'm not saying its that hard but there several tricks that you must figure out.

There are other minor issues as well but not enough time to discuss.

The big advantage is that you can run a giant cam and still maintain excellent driveability and street manners.
(I've driven my car to the track, run mid nines in average air and driven home with 10 minutes of preparationin the pits and idling at 600 rpms.)
Without an ITB or other new design of manifold you will lose alot of that streetability and now you have a car you can't enjoy on the street.
Basically you can have it both ways right now with the parts available.
I bet DBN would agree here as he has built both a street car and racecar that has seen mid nines and soon mid 8's n/a.

Don't forget rollcage/parachute, and the proper size tire necessary for traction. Now with the right tire you don't have the gear in the rear or trans to support it on the launch pad and through the traps and on the shifts. So, as you can see a whole host of problems emerge when 8's come in to a discussion with late model corvettes especially n/a.

A true H/C c6Z that runs any 9 is impressive in its own right.
There's no doubt we can put together a mid nine second car but the streetability will take a hit and the customization necessary will creep in heavily.
Then the dilemma comes up. Do I want to do this to my car?

If the question is can a late model 6 speed vette run an 8.99 n/a with a 427 and still wear a state liscense plate? My answer is Yes.

 

Excellent write up.....But of course I have some rebuttals and questions for ya....

1) Do you feel the manual car is a hurdle or an advantage in this situation ?? Why ? DBN is auto so...?? (t-brake vs 2-step/parasitic loss etc..)

2) With the aforementioned 8.999999 combo...what do you feel would be the minimum tire capable of such a feat ?? With a manual....on a world class track.....

3) With your firsthand knowledge of the ITB did you guys find success with the first wave or fourth ?? And what were the differences in VE % between the two, if any ??

4) In regards to the ITB packaging constraints, have you guys considered a simple hood pan ?? With an adequate forward or aft facing opening in the hood...depending on your belief of the effect of ram air vs aero drag ?? And would act as a heat shield and direct fresh dense air towards the trumpets.




5) In your opinion, how light can a C6Z become.........but not gutted (keeping A/C, air bags, ABS, all electronic gadgets etc..) ?? With all the safety regs met ??

6) And............................where the heck is Gary ????



Thanks.................

 

Retired per robz.
Setting up rentals for all to enjoy.

 

:d

 

Great discussion. As always, the hardest part of this equation to pin down is one's definition of a "street car." My opinion is that a manual car with the slipper clutch is worth a couple of tenths over the auto car, especially if driveability and the ultimate timeslip is the goal. I believe that an auto car is more consistent at the drag strip however. My experience has been that it is possible to build an auto car that can be driven cross country and still go into the 9s N/A. I did that (9.95@136.90) with a hydraulic cam 427, GM plastic intake, 90mm TB, and MAF. Mid 9s are possible if street driving is very limited. Also done (9.58@144.83) with basically the same engine combination and additional work to the car. This was done at around the 580rwhp level. The trade off is that to get an auto car to run quick, one must use a loose torque converter, which does not work well when driven on the street for extended periods of time due to excessive heat build up. I am not going to say that an 8 second N/A "street" car is impossible, but I believe that it is not very likely. I have since made several 8 second N/A passes in my auto C5, but it is in no way shape or form close to being a street car. I think that mid 8s N/A are just around the corner with some changes to the car and fall air. Time will tell. Stay tuned. Good luck with your project.