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-   -   My twint04 car runs again! (https://www.rx7club.com/single-turbo-rx-7s-23/my-twint04-car-runs-again-572219/)

rfreeman27 08-26-06 12:29 PM

My twint04 car runs again!
 
3 Attachment(s)
Finally!

After constant setback and lack of time, my project is back together.

On my first attempt I used borg warner s300 turbos. They out flowed the engine at low RPM and created a massive surge problem. When you made a pull from high rpm (say downshifting into third...) they worked fine. However the surge was an unacceptable flaw. We tuned to 18lbs on the street, and it was scarry fast.

I downsized to s200 turbos with a .76 ar. The car's tune is way off, but there have been zero surge problems so far. I need to get tags on the car for more testing and street tune.

In the near future I am going to change the manifold. I do not like the way the turbos are positioned. Also, I am going to run dual 3inch exhausts (they are 2x2.5 into a 3 currently) and dump them behind the rear tire or merge into a 4.5 inch oval. An intake mani is in the works as well.

The car isnt completley done, I still need to make some lines, the vaccume hose you see here is temp.

Overall goal is to break the 10second barrier

Setup:

Twin borg warner s200
Twin tial 40's
Custom mani, d/p, exhaust
Ported engine
TECIIIr
PCS d200 digital datalogger dash
A1000 fuel pump
850/1600 (prolly going to swap to all 1600's)
sumped tank
E-water pump
etc...

rfreeman27 08-26-06 12:31 PM

almost forgot,

Trans is a jerico 4 speed unit with sintered iron clutch and the heaviest pressure plate act offers. (talk about an on off switch...)


i think my camera snorted some coke, check out the third pic haha

jfxp 08-26-06 12:53 PM

What kind of instrument display is that?

Nice car btw!

CMonakar 08-26-06 12:53 PM

Looks good!

p4nc7 08-26-06 12:56 PM

COOL! Now give me your car. =D

Turblown 08-26-06 01:17 PM

Glad to hear its back up!

rfreeman27 08-26-06 02:04 PM

Thanks guys.

I just took the car out again (man i need tags :)) and its fun as shit.

just running 10lbs on wastegate, full boost at 4500ish...



the dash is from Powertrain Control Solutions. It isnt on the market yet, but the thing is kickass.

It plugs right into the tec, has 9 inputs, boost controller (which is awesome btw, better then the AVCR as displayed on dee K's race car) gps, gmeter, etc.

for more info go to www.powertraincontrolsolutions.com

I'm going to try to tune this week. Its tough though because I go back to school tomorrow, and its about an hour from my shop...

Also in this round of mods, I relocated all the fuse boxes to the rear, rewired the tec, made a pretty trick coil mounting bracket, removed abs and installed a linelock, simplified the body harness, dual earls coolers

I need to get the thing painted too, i have a feed kit sitting around here somewhere...

21K95RX7 08-26-06 02:10 PM

badass!!! what kinda numbers do you expect? what did you get on that 18psi with the other setup?

rfreeman27 08-26-06 02:25 PM

3 Attachment(s)
I never dynoed. It was using the fuel for ~590 ish, which felt about right.

I want to make 700. thats enough for the 9sec pass.

here are a few more pics. I still have a lot of finishing work to do, tieing wires and wrapping, etc.

21K95RX7 08-26-06 02:31 PM

do they run sequentially? that would be a sick powerband

rfreeman27 08-26-06 02:36 PM

no, non sequential.

EZFD 08-26-06 04:48 PM

That is a pretty sick setup, i love the twins!!!

tdazmansFD 08-26-06 06:45 PM

Gret setup! Props for the creativity! I remember seeing your posts from the past and wondered how that was coming along. Good luck with last bit of finishing work...And post some damn vids next time LOL.

Howard Coleman 08-27-06 12:57 PM

it is great to see your twins back on the road.

i am happy to see you have resized your turbos and it certainly looks like you are in the right area for your needs. the HT200 makes approx 56 pounds at 3 bar so doing the math

56 X 2 = 112 pounds per minute.

112 X 14.471 = 1620 CFM/ 1.92 = 844 rear wheel rotary hp

or figured another way

112 X10/ 1.3 = 861.

you probably will need some additional injection capacity.

i run 2 TO4s and have 84 pounds per minute. i currently have 8800 miles on the setup and within 30 days of dynoing.

i always look at turbos by taking the two diameters for the wheel, solving for the area and them averaging the area.

your old turbos HT300 were 6.927 cold area X 6.926 hot

your new turbos HT200 are 5.77 cold area X 5.882 hot

looking at the leftline surge area i can feel your pain w two HT300s:)

once you get that tuned-out you are going to be riding a Saturn rocket.

good luck

howard coleman

rfreeman27 08-27-06 06:12 PM

the reply I was waiting for...

I have a 1600 primary rail sitting around somewhere. I havent installed it because i wanted to at least test low boost to see if the turbos were hitting the surge line, and didnt feel like starting completley over with the tune.

good to hear your setup is still going strong.

Being at school throws a serious wrench in tunning plans. Ill get back sooner or later and get a street tune/dyno...

I gotta go get some more 11.50/gal c16 :(

red_ricer 08-28-06 03:48 PM

That is an awesome setup. Got any pics of the exhaust manifold itself?

Jay7 Nyc 08-28-06 04:13 PM

Wow beautiful twin turbo setup. Kudos!!

rfreeman27 08-29-06 08:33 PM

I dont have any pics of the mani right now.

When i redo it i will take pics.

Fd3BOOST 08-29-06 10:22 PM

Bobby, looks good. Been a long time coming. I hope it works out and see you in the spring. :)


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