Gain 100HP with an intake manifold change?? - Cross post from Ferrari Chat
#496
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I was tempted to say you obviously never held the gas pedal down long enough.....but that would have been unkind
Oh and at Nardo the neutral speed is 150 mph any more and you MUST be turning all the time which slows the car !! and makes it a constant sweeper despite the banking. An endless 12.5 KM "corner".
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#497
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Mark your former Holbert "stock" S-4 did 176.3 clockwise and 181.8 counter clockwise at the Nardo ring in April of 1986 !!! Prior to taking it to Bonneville where altitude and tire slip took their toll. Speed was said to have been with stock exhaust including catalytic convertors....
remember Bonneville was probably mainly limited by wheel slip, as the air density at 4500ft, is 15% less than at sealevel, which is a big deal at that speed. so, they even did it in that boggie 5th gear......but there was lots of time to accelerate, but did it at the no so perfect , 5000rpm, well below peak HP. my guess is that they used a lower gear box to achieve the records.
peak hp for the holbet car is aroud 5700rpm, and at 5000rpm, HP levels are only about 82% of max. I estimate, round 240rwhp!!!!! so, its tough to think that they did it with the stock 2:2, but I guess its possible.
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They had at least two transmissions at Bonneville one a 2:54, ran 7 inch wheels on all four corners, no exterior mirrors, and the brains were fitted with external chip holders for " quick chip changes" to no doubt bump the RPM.....and an extended under tray and also ran it lower than stock.....not to mention the 1986 camshafts that happened to be in the engine
All to set a record for a stock production S-4.....yea right !!! some mention of a larger front stabilizer bar....
All of which is why I have always questioned how "stock" that original engine actually was......they went to Bonneville determined to set a record. Built an S-4 out of an 86 shell long BEFORE actual production ever began, did several small but obvious cheats to make it happen. And did extensive testing at Nardo in Italy to prove that it was fast enough and could survive....
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All of which is why I have always questioned how "stock" that original engine actually was......they went to Bonneville determined to set a record. Built an S-4 out of an 86 shell long BEFORE actual production ever began, did several small but obvious cheats to make it happen. And did extensive testing at Nardo in Italy to prove that it was fast enough and could survive....
#500
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They had at least two transmissions at Bonneville one a 2:54, ran 7 inch wheels on all four corners, no exterior mirrors, and the brains were fitted with external chip holders for " quick chip changes" to no doubt bump the RPM.....and an extended under tray and also ran it lower than stock.....not to mention the 1986 camshafts that happened to be in the engine
All to set a record for a stock production S-4.....yea right !!! some mention of a larger front stabilizer bar....
All of which is why I have always questioned how "stock" that original engine actually was......they went to Bonneville determined to set a record. Built an S-4 out of an 86 shell long BEFORE actual production ever began, did several small but obvious cheats to make it happen. And did extensive testing at Nardo in Italy to prove that it was fast enough and could survive....
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
All of which is why I have always questioned how "stock" that original engine actually was......they went to Bonneville determined to set a record. Built an S-4 out of an 86 shell long BEFORE actual production ever began, did several small but obvious cheats to make it happen. And did extensive testing at Nardo in Italy to prove that it was fast enough and could survive....
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I dont know why you question how stock it was.... alll of those things they changed were within the rules. (from what i heard) AND, just because they used a stock grind, 85 camshaft which became the GT cam, doesnt mean it was a cheater motor. heck, the cam was from the prior year !!
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the engine internals were stock . it was truly the first S4 engine, #00004
not even a squirter block. stock bearings, stock crank, stock pistons and rods.. i showed you all the pictures of the disassembly. AND, it made no more hp than the same set up motor that Ron had with Mark. 320whp with headers.
it did have on it, some stock looking sway bar, that seemed to be porsche and it was larger than stock for sure. it survived ............for a long time too! i had 120race days on the car. LOVED that car!!! then, some idiot at the track, had to take it away from me. (us)....... very sad.
oh well
#501
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I thought the GT cams are not the same grind as the early 32vs. Also, the engine configuration that you endex up with could easily be totally different than what they had for the land speed runs. I would not be surprised one bit if the engine looked like and S4 but it was bigger out to make a lot more power than the factory spec. Did Guinness check what the internals were?
#502
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I thought the GT cams are not the same grind as the early 32vs. Also, the engine configuration that you endex up with could easily be totally different than what they had for the land speed runs. I would not be surprised one bit if the engine looked like and S4 but it was bigger out to make a lot more power than the factory spec. Did Guinness check what the internals were?
#503
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Come on Brother. The 86/85 were basically S4 with a better intake ![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
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They had at least two transmissions at Bonneville one a 2:54, ran 7 inch wheels on all four corners, no exterior mirrors, and the brains were fitted with external chip holders for " quick chip changes" to no doubt bump the RPM.....and an extended under tray and also ran it lower than stock.....not to mention the 1986 camshafts that happened to be in the engine
All to set a record for a stock production S-4.....yea right !!! some mention of a larger front stabilizer bar....
All of which is why I have always questioned how "stock" that original engine actually was......they went to Bonneville determined to set a record. Built an S-4 out of an 86 shell long BEFORE actual production ever began, did several small but obvious cheats to make it happen. And did extensive testing at Nardo in Italy to prove that it was fast enough and could survive....
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
All of which is why I have always questioned how "stock" that original engine actually was......they went to Bonneville determined to set a record. Built an S-4 out of an 86 shell long BEFORE actual production ever began, did several small but obvious cheats to make it happen. And did extensive testing at Nardo in Italy to prove that it was fast enough and could survive....
#504
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Mark--
Event notes say that they tried both gearboxes, and had exactly the same results. Kind of points to downforce and traction issues as the limiting factors on the salt. Tires slipped on the salt regardless of the gear ratios used to spin them.
This is a case where modern traction management would give you a percentage of slip, then start dialing back power as slip percentage went beyond the 8% or so considered max allowable (in my dark ages anyway).
Event notes say that they tried both gearboxes, and had exactly the same results. Kind of points to downforce and traction issues as the limiting factors on the salt. Tires slipped on the salt regardless of the gear ratios used to spin them.
This is a case where modern traction management would give you a percentage of slip, then start dialing back power as slip percentage went beyond the 8% or so considered max allowable (in my dark ages anyway).
#506
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Here is a quote from Jim Morton after some flow test on a stock S4 manifold
For those interested in another opinion on the OEM manifold, it is actually ahead of its time with the flappy resonance concept. For a street car the flappy / cross resonance idea likely adds noticable bottom end torque... a good thing. The issue is how the poor flow of the runners limit the size of the engine on the top end. For pure street use on a 5.0 or 5.4 engine, I am not sure I would throw out this manifold so quickly. As Sterling mentions, there are other areas of restriction to look at.
If drivability through out the RPM range is desired, the OEM manifold is likely better than any aftermarket venture, given what a good development effort costs.
So other then a pure track application where the revs are a the top of the range all the time there's no real need.
For those interested in another opinion on the OEM manifold, it is actually ahead of its time with the flappy resonance concept. For a street car the flappy / cross resonance idea likely adds noticable bottom end torque... a good thing. The issue is how the poor flow of the runners limit the size of the engine on the top end. For pure street use on a 5.0 or 5.4 engine, I am not sure I would throw out this manifold so quickly. As Sterling mentions, there are other areas of restriction to look at.
If drivability through out the RPM range is desired, the OEM manifold is likely better than any aftermarket venture, given what a good development effort costs.
So other then a pure track application where the revs are a the top of the range all the time there's no real need.
#507
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Correct Porsche designed a pretty good manifold for the purpose intended. Now start putting in modified cams, increasing displacement, proper exhaust , and spinning the RPM up or ALL of these and no surprise it comes up short.
The initial post about the Ferrari compared a stock car dyno to the modified intake being run with custom exhaust , aftermarket engine management so more fuel and ignition advance , and stock cams but advanced cam timing.... And had a big "improvement"...
Going to be fun to see Greg Brown's finished intake
The initial post about the Ferrari compared a stock car dyno to the modified intake being run with custom exhaust , aftermarket engine management so more fuel and ignition advance , and stock cams but advanced cam timing.... And had a big "improvement"...
Going to be fun to see Greg Brown's finished intake
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#508
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Wow, blast from the past by Cosmo...
To add some numbers to the discussion:
When working the stock S4 manifold, we found the manifold to be very unbalanced runner to runner. Many have seen this and discussed the issue. CFM values ranged from around 260CFM@25" to 285CFM@25" for the one best case runner.
After destroying one cast to investigate the flow challenges, we modelled possible porting using clay and testing on the flow bench. After several tests, we came up with a mod plan that got the worst runners to just over 280CFM@25". With this, we left the 288CFM runner pretty much alone. So, after a few thousand spent on flow testing / modeling, we had a port design for a S4 intake to have a range of flow at 280CFM@25" across all 8 runners.
Next up was trying tot solve a problem in the throttle body casting. When "flappy" was closed, the upflow out of the throttle body was not balanced by about 30CFM@25". Like the intake, we destroyed a throttle casting working to see how it might be modded for better balance. While doing this investigation, it brought up the question of where to place the throttle and how large the diameter. As I recall, for a 500HP/500 lb.-ft. torque engine plan (i.e. "square" force/power), the thotttle plate needed to be about 1/4" inch larger, but the need looked to be a fairly big project.
As many know, I looked at the overall value to continue with the costly development and elected to stop. I still think about these engines often and really admire those who keep up their well engineered developments.
Cheers !
To add some numbers to the discussion:
When working the stock S4 manifold, we found the manifold to be very unbalanced runner to runner. Many have seen this and discussed the issue. CFM values ranged from around 260CFM@25" to 285CFM@25" for the one best case runner.
After destroying one cast to investigate the flow challenges, we modelled possible porting using clay and testing on the flow bench. After several tests, we came up with a mod plan that got the worst runners to just over 280CFM@25". With this, we left the 288CFM runner pretty much alone. So, after a few thousand spent on flow testing / modeling, we had a port design for a S4 intake to have a range of flow at 280CFM@25" across all 8 runners.
Next up was trying tot solve a problem in the throttle body casting. When "flappy" was closed, the upflow out of the throttle body was not balanced by about 30CFM@25". Like the intake, we destroyed a throttle casting working to see how it might be modded for better balance. While doing this investigation, it brought up the question of where to place the throttle and how large the diameter. As I recall, for a 500HP/500 lb.-ft. torque engine plan (i.e. "square" force/power), the thotttle plate needed to be about 1/4" inch larger, but the need looked to be a fairly big project.
As many know, I looked at the overall value to continue with the costly development and elected to stop. I still think about these engines often and really admire those who keep up their well engineered developments.
Cheers !
#509
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Correct Porsche designed a pretty good manifold for the purpose intended. Now start putting in modified cams, increasing displacement, proper exhaust , and spinning the RPM up or ALL of these and no surprise it comes up short.
The initial post about the Ferrari compared a stock car dyno to the modified intake being run with custom exhaust , aftermarket engine management so more fuel and ignition advance , and stock cams but advanced cam timing.... And had a big "improvement"...
Going to be fun to see Greg Brown's finished intake![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
The initial post about the Ferrari compared a stock car dyno to the modified intake being run with custom exhaust , aftermarket engine management so more fuel and ignition advance , and stock cams but advanced cam timing.... And had a big "improvement"...
Going to be fun to see Greg Brown's finished intake
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Here is a quote from Jim Morton after some flow test on a stock S4 manifold
For those interested in another opinion on the OEM manifold, it is actually ahead of its time with the flappy resonance concept. For a street car the flappy / cross resonance idea likely adds noticable bottom end torque... a good thing. The issue is how the poor flow of the runners limit the size of the engine on the top end. For pure street use on a 5.0 or 5.4 engine, I am not sure I would throw out this manifold so quickly. As Sterling mentions, there are other areas of restriction to look at.
If drivability through out the RPM range is desired, the OEM manifold is likely better than any aftermarket venture, given what a good development effort costs.
So other then a pure track application where the revs are a the top of the range all the time there's no real need.
For those interested in another opinion on the OEM manifold, it is actually ahead of its time with the flappy resonance concept. For a street car the flappy / cross resonance idea likely adds noticable bottom end torque... a good thing. The issue is how the poor flow of the runners limit the size of the engine on the top end. For pure street use on a 5.0 or 5.4 engine, I am not sure I would throw out this manifold so quickly. As Sterling mentions, there are other areas of restriction to look at.
If drivability through out the RPM range is desired, the OEM manifold is likely better than any aftermarket venture, given what a good development effort costs.
So other then a pure track application where the revs are a the top of the range all the time there's no real need.
Mark--
Event notes say that they tried both gearboxes, and had exactly the same results. Kind of points to downforce and traction issues as the limiting factors on the salt. Tires slipped on the salt regardless of the gear ratios used to spin them.
This is a case where modern traction management would give you a percentage of slip, then start dialing back power as slip percentage went beyond the 8% or so considered max allowable (in my dark ages anyway).
Event notes say that they tried both gearboxes, and had exactly the same results. Kind of points to downforce and traction issues as the limiting factors on the salt. Tires slipped on the salt regardless of the gear ratios used to spin them.
This is a case where modern traction management would give you a percentage of slip, then start dialing back power as slip percentage went beyond the 8% or so considered max allowable (in my dark ages anyway).
No, they are not the same lobs.... what gave you that idea? the GT and 85 cams have 10mm lift vs the S4 9mm lift
I allways thought that the old intake would perform better. i think it has a larger diameter throttle body. but , GB did tests and it didnt help when put on a S4 so i seem to remember him saying.... true?
I thought the GT cams are not the same grind as the early 32vs. Also, the engine configuration that you endex up with could easily be totally different than what they had for the land speed runs. I would not be surprised one bit if the engine looked like and S4 but it was bigger out to make a lot more power than the factory spec. Did Guinness check what the internals were?
by the way.. i measured the engine dims when i pulled it.. it was stock. nothing was out of the ordinary. stroke, bore, crank , rods, pistons... all stock S4
#510
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Doesn't matter what you measured if the engine was rebuilt to stock spec after the high speed record runs. As for the camshafts, as soon as you say "except" or "but" it's no longer the same. The only way to know the HP difference between the two cams is if they are run in the same engine, same conditions, same everything. Otherwise there are too many variables to know exactly what the HP difference is between the two.