Heh. The only thing stressin me with the GD3 is time and the age old question "Should I use one turbo, or two?"

You got PM :)

 

Wait.

2 turbos.

On GD3.

Explain this to me.

 

Very nice! Glad you guys got to get some passes in! The heat has been good for traction but killin everyone on power. Not to mention all this rain suddenly! We got 6.5" here!

Hope your vacation went well, in spite of the weather. The links you sent me made for good reading on my little break when we were stuck in the cabin cuz of the weather.

 

To elaborate... aside from my distinct lack of time and my funding schedule, the thing that has really held up my progress has been the turbo setup.

I'm expecting a good deal of nay-sayers and BS, but my favorite configuration has been compound turbos. Ever since I used an HX40 and an HT60 on my old 6BT Cummins.

Basically because of my goals 300whp/300wtq I am expecting to blow up at least one engine so the only thing I want to have to replace or upgrade is going to be the longblock as they are easy and relatively cheap to do.

So I am looking at using 14B with another S200sx series Borg Warner turbo, or a Holset HX35 or HE351VE, all of which I have at my disposal, including a couple others of various sizes.

I haven't really posted any of this here because I get sick of internet experts shitting on threads, no offense to you guys (Mike, Tex, Perrenoud, Vinny, SB, Lyon and several dozen other fine intelligent folks) its the other FF.net members who have robbed my enthusiasm for this place. If only temporarily.

In any event I am WAY behind where I wanted to be with the Fit because my Land Speed car takes priority.

I have everything I need to have the GD3 fired up and boosting by monday on a single GT25R or have the exhaust manifold flange and downpipe fabbed up and slap the 14B on, but I am no longer sure that that is what I want.

My Fit has to be unique I have decided.

If you are not familiar with compound setups (not sequentials or twins) this is what I am talking about:


Where on the exhaust side the small turbo gets fed first and then the wastegate and turbine discharge are both routed into the big turbo and then to the tail pipe. And on the intake side the big turbo is feeding into the small turbo.

This produces insane spool and torque with huge top end. It's also incredibly efficient. So the small turbo will be in the traditional position on the back of the block by the firewall, and the big turbo will be mounted in the factory battery location over the transmission. Similar to the way the K-swap turbo Fit's like Felix's use the Full Race turbo manifold for the EG chassis.


Except there will be a smaller turbo upstream between the engine and the big turbo.

For reference on the turbos I am discussing the 14B (35lbs/min max or ~320whp) is considerably bigger then the GT25R (28lbs/min or 240whp) 90% of the turbo fit's on this forum are running. I am considering running a 14B and an HX35.

The picture below shows the 14B on top, at lower right the HX35 (58lbs/min or 550whp) and an HX52 (80lbs/min or ~770whp) on the left:

 

My old avatar was the engine. A b20 with a gsr head. The motor has over 150000 unknown miles on it. They threw a supercharger and a few other goodies at it and you have a 12.5 car.

I got sun poisoning at the track and had a rough week but glad I did not have to work, the trailer temps would be over 150 degrees. It was hot in the house but I made the best of it.

 

Probably better than 12.5sec with some seat time! Hope your feeling better, I over exerted myself in the heat the other day and didn't feel right for two hours after.

Hopefully it cools off for you when you get back on the road!

 

I like the new avatar btw!

 

They had problems with axles breaking and turned down the boost and added water injection to give consistent runs. Lots of low end torque and different than turbo according to the owner/tuner. He likes turbo better but that is because that was all he tuned. I had a allergic reaction, my legs are still swollen and red, but don't hurt as bad.


The avatar is our bull dog. Hes a cool dog at times.

 

Wow. That could be crazy. I'd love to see what a Fit could do with that setup.

I know I haven't always seen eye to eye with you, but its nice to disagree with someone who can actually think logically and back up their beliefs!

 

Agreed. I think we were to have a beer and talk politics sometime!

The compound turbo setup on a spark ignition engine is something I have been mulling over for a while and just wanted a platform to do it on.

It's already been done on a few DSMs. It is common place on diesels.

Definitely a first as far as I am currently aware of in the Honda community. If not, I would like to at least have the first Fit with that configuration. :D

I think it might be the only way to hit 300wtq in our 1.5s, but to package it in such a small workspace I may need to run a hot pipe with a couple water injectors between the turbos with a 32" X 13" x 4" intercooler after the secondary turbo.

Then run E85 as my primary fuel. This all requires me to convert the stock fuel system over to a return style system by modifying the pump hanger assembly, T-ing off the rail to a regulator.

So I figure I'll use an Aeromotive AFPR, a walbro gss341 in-tank pump, and a bosch -044 in-line to support the total fuel pressure and volume such a setup will require.

Probably -6AN PTFE lines for feed and return with at least one Golan SS 10-micron filter element.

 

Actually the more I look at this I may end up using one of those little GT2554Rs as the small turbo to make my torque goal..

I think the easiest way someone could do something similar would be to use a Kraftwerks High boost kit and a Greddy/T1R/HKS Turbo kit on the same engine with an AEM EMS.

That would be a bolt on twincharger system. Very expensive though..

Feed the turbo into the supercharger, say 15psi wastegate pressure (2.0PR) and 10psi pulley (1.7PR) respectively and your making ~35psi boost in the manifold.

1.0PR is atmospheric pressure at sea level, which is 14.7psi absolute or 0psi boost.

2.0PR is 29.4psi absolute or 14.7psi boost

So in a compound system you are starting with whatever your altitudes current atmospheric pressure is and then multiply it with the pressure ratios, then subtract the starting atmospheric pressure to find boost.

In this example, in my area the altitude is only ~650ft above sea level. For the sake of convenience and clarity I will just pretend we are at sea level.

So the turbo is pushing ~15psi boost (29.4psi absolute), which is compressing the incoming charge at a pressure ratio of 2:1, then it enters the supercharger which is using a 10psi pulley which further compresses the charge at a ratio or 1.7:1.

The turbo at 2.0PR feeding the supercharger running at 1.7PR makes a final PR of 3.4.

3.4 times 14.7 gives us the total absolute pressure of the system at the manifold, which is 49.98psi absolute. Subtract 14.7psi (atmospheric pressure) from 49.98 absolute and you get our boost pressure of 35.28psi!

The cool part about using the Kraftwerks S/C with the quick spooling small turbos from the T1R/HKS/Greddy kits is that while the turbo makes full boost and holds it to redline (more or less, but thats another discussion) the KW Rotrex S/C only makes full boost at or very near redline.

This means power climbs all the way to redline so it never feels like power has tapered off. What's yet more cool is that what effectively is occuring is that by the time the turbo in this example is fully spooled, the 2.0PR has made our 1.5L engine a 3.0L.

The supercharger will have started to make a couple pounds of boost as well at this point so it will technically be more than that, but at redline with this example the Fit will have grown from a 1.5L at idle to a ~5.1L engine at full boost at redline!

The craziest bit about all that is if you never drive around in boost, you will retain stock fuel economy.

Mind = Blown

 

DSM, I think most us at some point have gotten so piss'd at this forum that we vowed never to come back, or for at least a long long time... But for some reason we get drawn back here. Why? Becuz at some point and time we've realized that people are shitting on us becuz that's the way they feel about them themselves in their souls but can't convince themselves that that is so...
Hey man shoot for the stars, I'm pretty shua you will capture your dream eventually.... You are a wealth of knowledge ma'man....

 

I think that is a pretty wise perspective, kudos Vinny. In addition to that incredible attention to detail you always seem to have a fantastic attitude which I can't exactly say about myself!

Thanks for chiming in man.

This is one project that will take a long time coming, but will be as perfect as I can make it when it comes to life.

Then you and big Mike will be my aesthetics coaches! Some day I hope to own a Fit oriented performance/fabrication company.

I feel like that would be the best way for me to give back to this community as well as expose it to bigger and better things since we seem to be losing innovators, manufacturers and developers for untold reasons.

 

We should all hang around and enjoy these Fits for what they are, AND what they can be. I'm getting more attached to mine as time goes on, and mostly because of what the Fit is good at right off the factory line.

Good luck with your projects man! Your knowledge around here is always appreciated.

 

After reading your posts explaining the compound setup....my mind asploded.

We'll have to have a Fit meet sometime soon, we've got a pretty good little group in IL/WI. See if Kenchan wants to bring his 370z lol

 

Umm subscribed

 

Agreed! I find myself more enfatuated with the car as time goes by.

Cannot wait to get down to TX to hopefully meet up with you, Tex JCrim and the rest of the Tex Fit Folks!

Haha That would be fun, the IL/WI guys seem to be a pretty laid back crowd. Maybe we could find a track or bar in a relatively convenient spot for everyone.

As far as the compound boost is concerned.. there is a couple ways to do it, and they are all uniquely awesome. Whether its a couple turbos paired together, some superchargers or even a mixed bag!

A friend of mine who was into tractor pulling first turned me onto them!

 

:D

I would like to develop a limited run kit of this sort, just don't have the capital currently. With so many styles of superchargers and turbochargers the possibilities are damn near endless. You could custom tailor it to your wants/needs!

If anyone has the funds and wants something of this nature done to their car, I would LOVE to set it up for them.

 

I have $22 dollars. Let's make this happen!

Also, I set up a thread for a meet.

https://www.fitfreak.net/forums/uppe...ke-happen.html

 

My single turbo plans added up to about $1100, I am expecting the compound setup to run me closer to $2500-3000, and thats including me using junkyard and pre-owned parts.

A lot of that number is going to be tied up in an AEM EMS. I figure at least a couple hundred for the exhaust side staging fabrication.

I should be around on 8/20 so I would be down for that. Where would you want to try and gather everyone?