SUpercharger bleus .. i need input !

[frank280zx]

OK here it goes guys

 

i have been talking to tony and with xander about this idea ...

kjones did it ..

but !!!

 

her is my goal! I want to build one of my cars to be a good allround track/autox car .. im planning to do this with an eaton charger at 8 psi of boost the charger is a 3.8 GM (pontiac gtp) Unit.

I will use a cam as i want to max out round 7K rpm and have power from 2500 rpm and up or possibly lower, that is where in theory the SC should help ported e88 and here is the catch !10:5 compression, i will run MsS

 

im looking for 250 and the highest possible avarange HP to the ground combined with torque

 

I will run 98 octane gas

 

here are some details i can choose from four cams:

 

270*/.475

 

290*/.490*

 

306* / 530*

 

290* / 600*

 

SO witch one would you use knowing it is a supercharged car as well .. i would think the 290*/.490*

 

Then how about the compression ratio? would you bring it down?? like said i dont want big boost numbers. but maximum.

at this point im not planning forged pistons but eurospec flat tops.. these are listed in the NISMO parts list, these have a dome some that is how the compression gets up there..

The other choice would be to use a set of Cosworth pistons ( domed) i have laying ..

They use 240 rods and are the ones that are pictured in the how to modify book..

But i would bet they up the compression even more to a region that i cant boost em without using full race gas!. however i could compensate that with a copper HG

 

the head is a fully prepped e88 and it will exit through a MSA 6-1 header and a 2,5 or 3" exhaust

 

 

the bottom line is us euros have not got loads of experience with superchargers ... who can fill me in ..

i know a good na set up could even bring me that power but a supercharger is just cool to have ...

 

 

What would you do .. any input is welcome here

[CantZme]

as far as compression goes, u might want to lower it a little just to insure your motor. Generally 10.5CR is not a safe compression ratio for a boosted application, but with good tuning using a wideband or dyno with some high octane gas u should be able to prevent detonation. I would recommend using the HKS 2mm headgasket as well, which would bring your compression down to mid 9's i'm guessing. You'll still have great off boost response and build boost quickly wth a compression ratio in the 9's but you'll be able to run your desired boost without worrying.

[frank280zx]

hmm intresting so you would say low 9's or high? i just wonder what boost i can run at what CR given this set up. the supercharger from what i understand doesn't do much above X rpm..

 

It just has to be there to fill the low rpm to mid range

 

The only way to drop the cr would be using a hks or a copper ( that i have laying around )

 

but for the simplicity a felpro gasket would be nice.. should have my books here to see what comp ill get with the cosworth pistons ... anybody know ?

 

btw i did search but most of the post go in detail on turbo applications.. i wonder where they differ from sc.. I would wonder how you would go about this given the facts of the pistons and e88 head

[frank280zx]

Just some extra input the euro squizpad flat tops take about 2 cc of space .. my e88 head is either 38 or 42 cc i have the remeasure ( chambers have been changed etc)

 

these pistons with a p90 make the comp 8.7 but i would want to be above 9 round the 9.5 mark any ideas given this imput

[mrcheeze36]

Frank,

 

Respond to the PMs and emails I've been sending you. You said you would send my part Next Day Air last Thursday but I haven't heard from you for over 2 1/2 weeks.

[Tony D]

SC not working above "X" rpm? Who said that? Better tell the NHRA Guys!!!

 

I would also run less compression. I would NOT use the MSA header! (I know you have one...er yeah, one...) That setup will need a larger primary tube than a regular L-Engine due to the volume increase by the SC. Either Doug Thorley or Burn Stainless can assist in supplying a header or components to build one. For that setup I would make the header myself as "off the shelf" headers will not give you the correct tue length nor diameter. It's not as hard as everybody makes it sound, and if you go through Burns Stainless, the engineering fees are refundable through a credit towards a purchase of one of their merged collectors.

 

We passed both places while you were here with Xander! Passed Burns on the way to Porterfield Brakes, and Doug's place when going by Aircraft Spruce to my house!

[Xander]

hey tony,

 

did you ever get that pm I send ya?

 

just wondering if you read your mails at Hybridz.

[Tony D]

Oh, I see it now. Along with 67 others...

 

Yes, I read my PM's....er, now

 

Congrats on Wendy and the "offspring" LOL

 

Nino is in football, band, and we fitted the 510 with the SSS induction system (using the Fairlady Z 2 Litre Jets and Needles) but still have to figure out how to adapt the exhaust system before trying to drive it around the yard!

[frank280zx]

He tony ill drop a line to so what and how.. i still lean somewhat to a super turbo though ! and just have one real hc NA set up for the fun. as i have Cosworth Forged pistons with a dome that will skyrocket the compression and a very nice cam to compliment this set up.

 

The supercharger solely is just a thought as a test bed so to speak.

Anyhow the ZXR is coming along fine and will be primered this week.. the project is well moving at snail pass

 

 

 

Looking forward to next MSA!

[Gollum]

I'm really not a fan of the idea of using a gasket to lower compression. If you look at your cylinder head chamber you'll notice it's not really pefectly round. When you raise that cumbustion chamber farther away from the pistons you're dramatically changing the look of the flame front and quench as well. These are the things that prevent detonation. You can't just tune around it. I'm sure you could tune it to not detonate, but you'll be at significatly less HP than the same setup using lower compression pistons instead.

 

Do it once, do it right. Just my .02 cents.

 

But I'd love to see another SC'ed Z.

[Xander]

gollum,

 

I thought about that aswell. If you use the p90 head with the hartshaped combustion chamber and use flattop pistons that you get a really good quench area. Aspecially if you use the european flattops (they have a raised squichpad). This makes for a rather compact combustion chamber at TDC. But if you use the dished turbo pistons this whole idea is pretty much gone anyway. So I don't think that using a 2mm gasket is going to change much.

[z-ya]

I have a JCR SC (Camden) on my L28 race car, and so far I've got 255WHP out of it at 8psi. I'm running very conservative timing (20 deg at 8psi).

 

Hear are the details:

 

- F54 flat top block and pistons.

- P79 head (round port 6:1 header)

- 2mm Gasket (8:1 CR)

- Comp Cams 280 dur, 460 lift cam

- Intake and exhaust ports matched

- Camden supercharger and JCR intake manifold

- Megasquirt running Extra code v029

- Ford EDIS-6 ignition module

- 36-1 crank wheel with VR sensor

- Chrysler coil pack (uses GM HEI plug wire connectors)

- Six 370cc/min Ford Thunderbird injectors

- Stock ZX FPR

 

Comming soon:

 

- Water injection controlled by MS

 

 

 

Dyno plot, bottom plot is before supercharger:

 

My recommendations:

 

- Use only a P79 or P90 head as these are less prone to detonation

- Shoot for a max CR of 8.5:1

- Run water injection or some other form of intercooling

- Run some sort of crank fired direct ingnition.

- Fuel injection only for this application

[frank280zx]

Z YA Thanks!!!

 

This is a very usefull reply.. do you have a close up of that intake? As im still debating an intake to modify to accept the SC.

I have also thought of an standard IC but then the SC would have to move to the pass side of the car with a tank under it ... any ideas on this ? i would be less hassle while in use than a water injection of some sort .. your horspower seems very close to my goal, as this is plenty on most tracks

 

And what do you mean by FI only ?

[z-ya]

 

Doing an air to air IC with style of SC is difficult. What does the SC you plan on using look like? Water injection is actually very easy, you just need to fill up the tank before each session.

 

The car is very fast at the current tune. I pull way from 5.0L Mustangs on the straights (and in the turns for that matter). When I get the O2 injection running, and get a bit more agressive with the timing, I should be in the 270WHP range at the current boost level.

 

FI, meaning fuel injection (programable). Don't try this with a carburetor.

[frank280zx]

 

 

It is an eaton of a pontiac GTP It looks like this!(not an actual pic!) So very close to yours.

 

How did you find that manifold *edit* i found out it is a kit but from where and $?? *end edit* did a search om JCR intake manifolds but to no avail that is no buying adress .. sure would make life easier!.

Seeing the pics confirms my initial plans of mounting, i just need to modify an intake (read built)

 

How did you solve your belt drive? i have ideas, and have seen easy adaptable Pulleys for them on the summit site

 

And dont worry i hate carbs.. im planning on MsS for this with a wide band o2

 

nice harbor freight engine stand btw

[frank280zx]

OK found out it is jim cook racing i send a mail to check if they only sell the manifold at a prize that is more reasonable than having one custom built, as i still have to fiddle with it .. anyone here have one to spare ?

[z-ya]

I like the GTP supercharger because it has provisions for a side draft throttle body. Making a cold air intake setup for the JCR kit will be a pain. I haven't figued out exactly what I will do about it. Right now I have some chicken wire over the TB to keep anything large from getting in there.

 

Your best bet is to make an intake manifold for the GTP SC. Can you get the intake off the GTP? Between that and a 280Z intake, you might be able to fabricate something. The othe rissue is hood clearance. The JCR manifold tilts the SC way over to clear the hood.

 

BTW, I believe Camden superchargers still has JCR intake manifolds. They aint cheap though. http://www.camdensuperchargers.com

[Tony D]

Why would the throttle plate have to be mounted _on_ the supercharger? I would think a suitable pipe with a radius pointed wherever you had room would allow a throttle plate to be mounted pretty much everywhere, and give you a bit of "softness" on drop-throttle to prevent blower surge.

Frank's compressor has provisions for a bypass under drop-throttle, and when he starts fabbing it up on a JCR Plenum intake, will find he really should have kept that RHD Z-Car he had, as the rearward facing TB setup will make it hard to clear the brake booster. But he will find that making the cowl air intake area into a large air filter box will solve a lot of problems in the T/B Mounting arena! LOL

[z-ya]

Tony,

 

There is no need to mount the TB on the SC, as you sugested. I did it because there is was no way to come off the top of the SC with a resonably small radius tube, and clear the hood. It was easier to just mount the 2 barrel Jeep throttle body on top of the SC. Also, since the intake opening on the SC is rectangular, I though using the dual butterfly TB would distribute air more evenly across the SC impellers.

 

Ken Jones used a SC with the inlet on the rear, and used the inlet tube from Stillen (used on the 350Z Stillen SC kit). It fit amazingly well, with plenty of room.

[PapaCreech]

Wow guys doin searches (researching the SC thing, and the more i read of all these post the more i can clearly understand the process, it no longer seems as daunting! thanks!