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We got our roadcourse FD back on the dyno finally. This year we swapped from a stock port engine to a half bridge, balanced, studded built motor. Also we swapped to a 4 inch side exit exhaust, and added our ewp kit. Zero other power mods. I have only barely starting tuning also. Its too rich in the midrange and uptop. Not bad for 19psi. This is no boost controller, just a turbosmart 14.5 psi spring.
Here is the final. 24 psi in the midrange and 20psi past 5.5k
Its 92 degrees outside and intake temps hit 149 at the end of the pull.
We install 9180 next week, then if needed a 6 inch quality core.
300rwtq at 3krpms(15 psi)
400rwtq at 4krpms(22psi)
475rwtq at 4500rpms (24psi)
527rwhp at 7200rpms (20psi)
Scoot is installing & tuning one of our 8374 IWG cast kits shortly.
For those curious I did put the dyno in SAE and it read 519rwhp/467rwtq.
Looking back in standard mode we did make a run that made 533rwhp, but torque was down a little lower something like 459.. Pretty consistent power wise of the 35 pulls we did, both hot and cold. We never had any water or oil temp issues either. Also keep in mind we did not add any extra dowels, or oversized studs on this motor. Its just our 10mm stud kit, and I did take it out to 9k several times.
Here is the final. 24 psi in the midrange and 20psi past 5.5k
Its 92 degrees outside and intake temps hit 149 at the end of the pull. We install 9180 next week, then if needed a 6 inch quality core.
300rwtq at 3krpms(15 psi)
400rwtq at 4krpms(22psi)
475rwtq at 4500rpms (24psi)
527rwhp at 7200rpms (20psi)
I'm eager to see the comparison between the two turbos!! As I alluded to in the other EFR thread, I'm on the fence about whether I should go with the 8374 (focus on spool, but lower power) or the 9174 (higher power per psi, but potentially slower spool).
So I hate to admit this but if you watch in the beginning of the video you will see my alternator voltage wire start to move all over the place... There was a Massive boost leak. My intercooler coupler clamp was completely loose... /fail... I also found the hardline fitting going from my 4 port solenoid to the top of my wastegate canister was finger tight. I have corrected both of those things and we are going to re-dyno next week. I suspect we will have an increase in tq and horsepower... Stay tuned!!
So I hate to admit this but if you watch in the beginning of the video you will see my alternator voltage wire start to move all over the place... There was a Massive boost leak.
Uh-oh...
Random question/request... Since you guys seem to be the primary source for EFR info and sales in the rx-7 community, would you all be willing to share comparisons and graphs of the different turbos regarding response and power based on different ports and boost levels?
I know it seems rather intuitive (smaller will be faster response but less power, bigger will give more power, but slightly more lag, smaller ports will yield more power to the left, but lower overall, bigger ports will shift power to the right, but yield more peak, etc., etc., etc.) but I know it would certainly help ME decide which turbo I will end up buying in the next few months if I could see sheets of different turbos on similar setups, and similar turbos on different setups... I figure you guys probably have the historical data already just from developing the different kits and tuning the customer cars.
There is/was a similar thread by HC where he just compares dimensions and what he perceives to be optimal... but I don't think that really tells the full story. Actual results don't lie!!
^^ not trying to answer for them, because I would love it to find this out as well.
But, turbo response (time from throttle input to hitting max boost available at current rpm) is something that you can't see on the dyno sheet. It is going to be from data logs or seat of the pants experience.
---------------- Spool (maximum boost available per rpm) you can see on the dyno sheets. Just be sure you are comparing apples to apples (Dyno Jets to Dyno Jets). From what I have seen on the Dyno Jet charts of EFR 7670 and EFR 8374 the 7670 barely out spools the 8374. We are talking only 10-25 ftlbs torque better from 2,000rpm to 3,500rpm on the smaller turbo.
I think this is because we don't quite have enough exhaust energy with our usual set-ups to push the 7670 to its surge line, whereas Elliot has reported he has reached the surge line on the 8374 around 3,000rpms when pushing it.
It will take a quick spool valve to get the 7670 to near the surge line. I might make that my next project if I move the 7670 over from my FC to my FD by just using the stock sequential manifold and then my 7670 manifold.
This should kick up the 7670 response as well as spool.
--------------
I have been thinking of how to couch the question of difference in response between EFR 7670 and 8374 to Shawn and Elliot since they have by far the most experience with these turbos.
Would you guys say the response of the EFR 7670 on a 3" downpipe is better, equal or worse than the response of the EFR 8374 on the larger 3.5" downpipe?
^ Good point, forgive me for using the wrong vocabulary ^_^
I accept that there is no way to accurately predict exactly how the turbo will perform from one setup to another since there are simply too many variations in individual setups and tunes to account for. I am mostly interested in ballpark performance
I'm personally looking between a 9174 and an 8374, primarily EWG since I've got faith in the quality of my current manifold.
(Shawn/Elliot - I apologize for partially derailing this thread...)
So I hate to admit this but if you watch in the beginning of the video you will see my alternator voltage wire start to move all over the place... There was a Massive boost leak. My intercooler coupler clamp was completely loose... /fail... I also found the hardline fitting going from my 4 port solenoid to the top of my wastegate canister was finger tight. I have corrected both of those things and we are going to re-dyno next week. I suspect we will have an increase in tq and horsepower... Stay tuned!!
We would have already strapped it on again, but that would just **** other people off who are waiting for us to finish their cars. We are going to try and sneak it in early next week.
Here is the dyno from the stock port engine at 26psi the entire pull( 3.5" full exhaust, no EWP kit) below. Different dyno( in shoot out mode so replicates standard dynojet).
We would hop back on this dyno buts its never available... I would love to overlay it.
Took it to a dyno dynamics( reads 15 percent lower than dynojet). Here is what guys down in Aus use. Boost leak fixed it jumped to 22 psi. Made 526rwhp( about 600rwhp on a dynojet). Intake temps still 150 F at the end of a run on a 67 deg F day.
