greg davis
New Member
- Joined
- Jun 11, 2002
- Messages
- 15
I was disappointed to read in the GSXTRA (Nov/Dec 2003) that 12.50@107 with #16psi is the best to expect on 93-octane pump fuel.
Now I know that some of you will post you have gone faster than that on pump fuel and I do not regard Richard Lassiter as an expert by any means.
I am interested in building a combo that will work with pump fuel and provide good street performance to ward off any new ZO6 Vette that may like to play and with only 1or 2 trips at the strip a year where I may want to turn up the boost and go with race fuel.
I would think that I want to make boost as efficiently as possible and keep the intake charge temperature as cool as possible to run as much boost as possible with the given octane.
I am starting with a ’87 T-Type 72,000 miles, Posi, with only the current mods being a XP+ pump, Volt Booster, “237” regulator, KN filter with Kirban half lid, valve cover vents, throttle body coolant bypassed, Reds 93 chip (older model), OTC 4000E. It ran the 1/8mi at the BCA Nat’s at Bunker Hill, IN Dragstrip 9.27@76.88. These numbers do not mean much to me since they are not quarter mile times.
So after this springs currently planned mods of a TA49, 3” THDP, 2-1/2” exhaust, Hot wired pump, Adj. fuel regulator, Heated O2, 2400 stahl lock-up converter, Boxed upper and lower control arms, 275/50-15 BFG DR, New valve springs, New turbo oil line, New waste gate Y hose, RJC power plate? (haven’t made up my mind), Injectors (size to be determined) where does one turn next?
It would seem if my theory of making efficient cool boost has merit then does an intercooler upgrade make sense at this performance level. Would aluminum cylinder heads provide enough combustion cooling to allow more boost or does just the better airflow allow this? If better airflow obtains more allowable boost then are ported iron heads an advantage? I understand more air in more air out theory but was asking from a boost standpoint for the steel heads and I realize the cost of either of these items.
Or is mid twelve’s the limit of 93 pump octane?
I do not have a make or break set goal of E.T.’s but as low into the twelve’s or very high elevens would be nice in an everyday state of boost and tune.
I realize most posted signature times from people are with lots of octane and boost, if anyone would share the times with 93 octane vs. their race fuel times of their combo it would help me get a feel of where to proceed with my next mods.
So I guess really my question is what should my next bolt ons be for building a pump fuel recipe.
I also have not made up my mind on 3” cat vs. straight pipe. No emissions testing is required yet but if the negative performance difference is minimal (.2 E.T.) at this level I will use the cat and be limited to unleaded fuel only. Does the cat increase backpressure enough to cause a result on limiting boost?
An alky system is not out of the question but I am unfamiliar with all the systems in detail. I just checked out the SMC from a link here and at $349 seem like a good next step bang for the buck. Except when things go wrong in a system like that bad things are soon to follow. Are the alky systems causing problems with the cat or O2 sensor?
The car is not a daily driver and is running great at present.
I am not trying to beat a dead horse with this type of thread and I have read as many of the past threads as I could find but I am interested in my specifics and would like this to be a start to open a dialogue with some of you.
Thanks to all interested in helping.
Now I know that some of you will post you have gone faster than that on pump fuel and I do not regard Richard Lassiter as an expert by any means.
I am interested in building a combo that will work with pump fuel and provide good street performance to ward off any new ZO6 Vette that may like to play and with only 1or 2 trips at the strip a year where I may want to turn up the boost and go with race fuel.
I would think that I want to make boost as efficiently as possible and keep the intake charge temperature as cool as possible to run as much boost as possible with the given octane.
I am starting with a ’87 T-Type 72,000 miles, Posi, with only the current mods being a XP+ pump, Volt Booster, “237” regulator, KN filter with Kirban half lid, valve cover vents, throttle body coolant bypassed, Reds 93 chip (older model), OTC 4000E. It ran the 1/8mi at the BCA Nat’s at Bunker Hill, IN Dragstrip 9.27@76.88. These numbers do not mean much to me since they are not quarter mile times.
So after this springs currently planned mods of a TA49, 3” THDP, 2-1/2” exhaust, Hot wired pump, Adj. fuel regulator, Heated O2, 2400 stahl lock-up converter, Boxed upper and lower control arms, 275/50-15 BFG DR, New valve springs, New turbo oil line, New waste gate Y hose, RJC power plate? (haven’t made up my mind), Injectors (size to be determined) where does one turn next?
It would seem if my theory of making efficient cool boost has merit then does an intercooler upgrade make sense at this performance level. Would aluminum cylinder heads provide enough combustion cooling to allow more boost or does just the better airflow allow this? If better airflow obtains more allowable boost then are ported iron heads an advantage? I understand more air in more air out theory but was asking from a boost standpoint for the steel heads and I realize the cost of either of these items.
Or is mid twelve’s the limit of 93 pump octane?
I do not have a make or break set goal of E.T.’s but as low into the twelve’s or very high elevens would be nice in an everyday state of boost and tune.
I realize most posted signature times from people are with lots of octane and boost, if anyone would share the times with 93 octane vs. their race fuel times of their combo it would help me get a feel of where to proceed with my next mods.
So I guess really my question is what should my next bolt ons be for building a pump fuel recipe.
I also have not made up my mind on 3” cat vs. straight pipe. No emissions testing is required yet but if the negative performance difference is minimal (.2 E.T.) at this level I will use the cat and be limited to unleaded fuel only. Does the cat increase backpressure enough to cause a result on limiting boost?
An alky system is not out of the question but I am unfamiliar with all the systems in detail. I just checked out the SMC from a link here and at $349 seem like a good next step bang for the buck. Except when things go wrong in a system like that bad things are soon to follow. Are the alky systems causing problems with the cat or O2 sensor?
The car is not a daily driver and is running great at present.
I am not trying to beat a dead horse with this type of thread and I have read as many of the past threads as I could find but I am interested in my specifics and would like this to be a start to open a dialogue with some of you.
Thanks to all interested in helping.