Turbo update with pics
05-26-2005, 11:47 AM
#31
Racer
Thread Starter
Cobalt,
IC options would be an nice addition but designing,producing and installing a one off system would cost as much as the car did. The non-IC system installed now produces 7.5 lbs of boost with out any problems and has done this for the last 20 years. That 80-100 hp is more than able to spin the tires and keep a grin on my face. simple and bombproof... well sort of......
SilverSFR
IC options would be an nice addition but designing,producing and installing a one off system would cost as much as the car did. The non-IC system installed now produces 7.5 lbs of boost with out any problems and has done this for the last 20 years. That 80-100 hp is more than able to spin the tires and keep a grin on my face. simple and bombproof... well sort of......
SilverSFR
05-26-2005, 01:00 PM
#34
Rennlist Member
Originally Posted by tammons
My cars wastegate dumps to atmosphere and honestly i cant tell that its any louder at all.
SilverSFR,
What do you estimate your total Hp and torque to be? I find the GTS does a very nice job laying 2 strips of rubber for about 20-30 feet if I am in the mood.
The turbo on the other hand spins the tires with little lock up because all the torque just comes on at once and sends you to the rev limiter very quickly if your not careful. Although that surge of torque really gets you moving at speed which gives you an edge over equally powerful but non turboed cars.
05-26-2005, 01:14 PM
#35
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Originally Posted by cobalt
What kind of car? The 964 Turbos left exhaust pipe is the wg dump pipe and even though it has a small cat it is quite loud when open.
SilverSFR,
What do you estimate your total Hp and torque to be? I find the GTS does a very nice job laying 2 strips of rubber for about 20-30 feet if I am in the mood. The turbo on the other hand spins the tires with little lock up because all the torque just comes on at once and sends you to the rev limiter very quickly if your not careful. Although that surge of torque really gets you moving at speed which gives you an edge over equally powerful but non turboed cars.
SilverSFR,
What do you estimate your total Hp and torque to be? I find the GTS does a very nice job laying 2 strips of rubber for about 20-30 feet if I am in the mood.
The turbo on the other hand spins the tires with little lock up because all the torque just comes on at once and sends you to the rev limiter very quickly if your not careful. Although that surge of torque really gets you moving at speed which gives you an edge over equally powerful but non turboed cars.
05-26-2005, 01:39 PM
#36
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Brendan...with the CS set up that way you would see like 4 lbs at 3000 give or take. Remember, its airflow is related to the crankshaft speed only, not the load on the engine...that is why I prefer the turbo...nice and docile until you load it up...and it is based on load, not RPM...this is a critical difference! 18 psig is a lot...I would propose a turbo car with 14 psig would outrun a CS with 18 psig in an across the board test. Area under the driving curve is what you are after. If you can keep the revs up the CS works, but coming out of corners the mid range punch does a lot for you. You can short shift the turbo car and have lots of extra power compared to the others at the same RPM...more than you need...keeps the engine speeds down.
SFR...You should really check your ignition timing on that car...set it up to allow for pressure retard in the distributor while on boost. I take a full 8-10 degrees out with 10-11 psig and that is with intercooling. I believe these setups stock run 30 max advance, so on boost I'm at like 22. 7.5 psig is borderline....you go more and you will have to charge cool it. 928 pistons will not stand any detonation... With your setup an air-water would be easiest. Your pressure ratio will be a function of the length and diameter of the intake pipes and the discharge pipes of the turbo.
I'm re-routing all the lower pipes on the Goldmember this weekend...much cleaner than my prototype everybody saw at Wichita. You guys can see it at NC next weekend. I just ordered a set of Fuzion tires...they were reasonable and sound like they are good units....the ones on the front are at the cords and the rears...well let's just say those are plastered all over the city!
SFR...You should really check your ignition timing on that car...set it up to allow for pressure retard in the distributor while on boost. I take a full 8-10 degrees out with 10-11 psig and that is with intercooling. I believe these setups stock run 30 max advance, so on boost I'm at like 22. 7.5 psig is borderline....you go more and you will have to charge cool it. 928 pistons will not stand any detonation... With your setup an air-water would be easiest. Your pressure ratio will be a function of the length and diameter of the intake pipes and the discharge pipes of the turbo.
I'm re-routing all the lower pipes on the Goldmember this weekend...much cleaner than my prototype everybody saw at Wichita. You guys can see it at NC next weekend. I just ordered a set of Fuzion tires...they were reasonable and sound like they are good units....the ones on the front are at the cords and the rears...well let's just say those are plastered all over the city!
05-26-2005, 01:40 PM
#37
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I would say SFRs car is making about 330-345 HP and probably 380+/- ft lbs at the crank. WIth a new turbo it will be better because the new wheels are much more efficient than the old ones.
05-26-2005, 01:48 PM
#38
Racer
Thread Starter
Herr-Kuhn
When i got the car the retard side of the distrbutor(lower side not the driver/owner) was capped off..
What would this do? Good or Bad...
SilverSFR
When i got the car the retard side of the distrbutor(lower side not the driver/owner) was capped off..
What would this do? Good or Bad...
SilverSFR
05-27-2005, 06:30 PM
#39
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Yes, the vacuum retard should be dismantled...mine is uncapped, open to atmosphere... if not, under boost it would become a pressure advance! Your vacuum advance automatically becomes a pressure retard when you go into boost...start the car and put some pressure (Bicycle pump works well for this) into the vacuum advance port and then check the timing with and without the pressure...the difference is what you fold out on boost. You can take the vacuum advance canister off and you will see a link arm and a round stop to limit the retard. Both my cars have the round stop ground back about 1mm or so to allow for more retard on boost. Stock you will get like maybe 4 degrees...if you modify it you can get a lot more retard....too much and you will raise EGTs, too little and the motor can detonate..especially on a hot day running lots of boost. 951s run about 22 degrees total on boost (I think)...928 stock is like 30 max advance, then take out the -4 and you are at about 25 degrees or so...but remember you have no charge cooler. I would recommend shaving a little more out of it...but it depends...check the timing without the advance first...they may have set it low across the board to compensate. You want a good bit of advance while not on the boost, then pull some out on the boost. I went to a full 8 or 10 degrees on both my cars to offer some margin of safety.
While it sounds crude...the pressure retard method is progressive based on boost pressure...it is not like you pull all the timing out with a lb of boost...it is somewhat linear. Not an ideal setup, but it works and costs nothing (hard to beat that!). Most of the MSD boost control boxes you see can pull out 1 to 2 degrees of timing for every lb of boost...1*7.5=7.5 I would say you should check it out and see where you are...who knows they might have already shaved the stop on the canister on your car...it is an old trick from the 70s. A more ideal system is a complete map....boost as a function of RPM and manifold pressure...and possibly other variables too! That is why they invented Motronic!
While it sounds crude...the pressure retard method is progressive based on boost pressure...it is not like you pull all the timing out with a lb of boost...it is somewhat linear. Not an ideal setup, but it works and costs nothing (hard to beat that!). Most of the MSD boost control boxes you see can pull out 1 to 2 degrees of timing for every lb of boost...1*7.5=7.5 I would say you should check it out and see where you are...who knows they might have already shaved the stop on the canister on your car...it is an old trick from the 70s. A more ideal system is a complete map....boost as a function of RPM and manifold pressure...and possibly other variables too! That is why they invented Motronic!
05-27-2005, 07:44 PM
#40
Racer
Thread Starter
Herr-Kuhn,
Thank you so much for the top notch run down on why they capped off the retard(sounds mean).
If you dont mind i would like to use that quote on my up comming website. Now, if you could only explane why you need to use a FMU(Vortek) for fuel support instead of RRFPR's on boosted 928's
SilverSFR
Thank you so much for the top notch run down on why they capped off the retard(sounds mean).
If you dont mind i would like to use that quote on my up comming website. Now, if you could only explane why you need to use a FMU(Vortek) for fuel support instead of RRFPR's on boosted 928's
SilverSFR
Last edited by SilverSFR; 05-29-2005 at 11:40 AM.
06-01-2005, 01:32 PM
#44
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The rising rate regulator is used to ramp up the pressure to the injectors to increase fuel flow. It works, but is not the best way...but it is hard to beat it on cost. Your fuel pressure on boost is probably like 80-90 psig at the fuel rail!
06-01-2005, 04:03 PM
#45
Racer
Thread Starter
Herr-Kuhn,
So do you need to use both, RRFPR and an FMU. or just one over the other. What are some of the other boostards using in their setups? I am currently only using a 12:1 Vortek FMU and stock FPR's.
SilverSFR
So do you need to use both, RRFPR and an FMU. or just one over the other. What are some of the other boostards using in their setups? I am currently only using a 12:1 Vortek FMU and stock FPR's.
SilverSFR