There is nothing like... - Page 3 - LotusTalk

Feffman · 06-21-2007, 04:04 AM

Quote:

Originally Posted by StallionX

What do you consider maximum safe boost?

Stallion:

The common concensus among V8 owners for cars with stock cast pistons is about 12PSI of boost. I'm sure the car will handle short periods of more boost but it will eventually catch up.

Dannie French (1997 V8) just spent a fortune having Harry at Viking do his engine with the forged pistons, water injection, ARP head studs, blow-off valves, etc. and the car is fast but he has a vacum issue that is getting sorted. After it's all said and done the tranny will be the next weak link (see Lotus Ltd's ReMarque this month) and will need an upgrade, then the 1/2 shafts (from tranny to wheels) will be the next weak link.

Don't get me wrong, I LOVE the Esprit. My 1999 was plenty fast (topped it out at 175MPH) and for the most part I could never drive it at its limit. I simply had Johan's ECU upgrade, K&N air filters and free-flow catalytic converter/exhaust.

Feff

JeffYoung · 06-21-2007, 07:01 AM

Mark, how much boost does Johan's ECU run? Does it temporarily spike at 14+ lbs under initial hard acceleration like the 4 pot ECUs? Or does it limit boost to 12 lbs (less than 1 bar, right?)?

lotuson74 · 06-21-2007, 09:54 AM

Pocono sounds like it's the event for me - Thanks guys!!! Even better, my new house is only 15 minuites from there

I will sign up tomarrow

lotuson74 · 06-21-2007, 10:19 AM

By the way... I NEVER said 26psi is "safe" I said: that I have done it on 4 Esprits without any failures when done in the specific manner that I do it.
But I do believe 14 to 18 is safe with 109 unleaded race fuel (based solely on my personal experiances)
I am also aware about the half shafts being a potential weak link along with the transmission BUT... I have had no problems! and I drive them all very hard. Even doing one full dead stop drag race with my 04 in which a G-Tech was in the car. At that time I was running 26psi and had on stickier rubber, the car did 0-60 in 3.3, Quarter mile in 10.8 @ 148mph! I do think I got lucky not to have broke something (that's why I have not done it again)
I also run the car hard on roadcoarses at 15-16psi with no problems

Not on pump gas - You WILL blow it up on pump gas!

If you fear the driveline is weak - Use 155x75x14 four-ply tires on smaller wheels with an "under fender oil drip" as this will help preserve the driveline

StallionX · 06-21-2007, 12:32 PM

Quote:

Originally Posted by Feffman

Stallion:

The common concensus among V8 owners for cars with stock cast pistons is about 12PSI of boost. I'm sure the car will handle short periods of more boost but it will eventually catch up.

Dannie French (1997 V8) just spent a fortune having Harry at Viking do his engine with the forged pistons, water injection, ARP head studs, blow-off valves, etc. and the car is fast but he has a vacum issue that is getting sorted. After it's all said and done the tranny will be the next weak link (see Lotus Ltd's ReMarque this month) and will need an upgrade, then the 1/2 shafts (from tranny to wheels) will be the next weak link.

Don't get me wrong, I LOVE the Esprit. My 1999 was plenty fast (topped it out at 175MPH) and for the most part I could never drive it at its limit. I simply had Johan's ECU upgrade, K&N air filters and free-flow catalytic converter/exhaust.

Feff

why did you not do the 12psi adjustment then? I thought with the mods you mentioned that the Esprit should be pushing 190 top end and about 415HP?

StallionX · 06-21-2007, 12:38 PM

Quote:

Originally Posted by lotuson74

Cool Stallion. Is there any right turns?

Can't be the nascar track.

yes they cut the track in 1/2 and the rest is infield racing w/ tight turns.

JeffYoung · 06-21-2007, 12:42 PM

Don't know about the V8s, but the speedo on my SE was rather optimistic. My SE speedometer would report about 10 mph over the Traqmate datalogger at "speed" (say indicate 145 when really at 135) on track.

What was the "book" top on the V8? 178 or so? It does take a significant bump in horses to get another 12 mph at that speed.

mikelr · 06-21-2007, 01:03 PM

The old VDO speedos in the SE-S4s were mechanical and prone to being out of calibration. The newer speedos in post S4s were electronic.

StallionX · 06-21-2007, 02:55 PM

well if the car at 350hp can do 178, then I would assume the 450hp ones could do 190ish.. doesn't sound impossible.. with another 100hp..

JeffYoung · 06-21-2007, 03:04 PM

No, it is not that simple. Top speed is a function of wheel size, rear gear ratio, horsepower, coefficient of drag and frontal area. I forget how the equation works, but the gist of it is that as speed (and drag) increases, it requires more horsepower to bring out corresponding increases in top speed.

Not saying a 450 hp V8 Esprit can't do 190, just saying it is more complicated that looking at a 350 hp V8 Esprit's top speed of 175 and extrapolating up.

StallionX · 06-21-2007, 03:54 PM

I know all about that Jeffery.. I am taking into account the likely scenario.. I remember reading how many HP was required to get x number of MPH high in your top speed, I believe 100hp more is enough to bring you another 15mph starting at 178..

JeffYoung · 06-21-2007, 04:07 PM

It's more than just hp and speed. You need to know cd and frontal area. 100 hp might get an Esprit 15 more mph, but it wouldn't get a bread van, for example.

StallionX · 06-21-2007, 06:10 PM

I totally understand.. you might need to remove the big v8 wing also to get a few more MPH in the esprit.. too much downforce..

lotuson74 · 06-21-2007, 08:26 PM

What really limits the Esprit's top end is - whare the rev. limiter stops you. It should at least go to 7400rpm. which is only about 180 - 185mph. But... I have had mine stop me cold at 7000 rpm. one time and it let me hit 7600 another time (195mph.) and it was still going, but traffic interviened

Having driven your car stallion, I can tell you - it has ample power to hit 7400rpm. in 5th. But you will need a looonnnnnngggggggggggg streight to do it

StallionX · 06-21-2007, 08:36 PM

heheh yeah I've had mine up there.. maybe 180 or so I wasn't really looking at odometer at that speed.. it honestly gets up there pretty goddamn fast too..

Feffman · 06-21-2007, 09:06 PM

Quote:

Originally Posted by JeffYoung

Mark, how much boost does Johan's ECU run? Does it temporarily spike at 14+ lbs under initial hard acceleration like the 4 pot ECUs? Or does it limit boost to 12 lbs (less than 1 bar, right?)?

Johna's ECU is limited by the waste gates t the stock 9PSI. You have to switch the waste gate capsules to take advantage of the extra boost. His ECU raises the rev limiter a bit but also allows for more boost then Lotus' stock programming in the lower gears. Big difference I noticed is how much smoother it idled and drivability was easier.

Feff

Feffman · 06-21-2007, 09:07 PM

Quote:

Originally Posted by StallionX

why did you not do the 12psi adjustment then? I thought with the mods you mentioned that the Esprit should be pushing 190 top end and about 415HP?

Stallion:

The Esprit was fast enough as it was and in the event of a blown engine, the cost is around $10K-$12K for a good rebuild.

Feff

StallionX · 06-22-2007, 05:22 AM

I thought you just said 12psi was safe? how would that result in a blown engine?

JeffYoung · 06-22-2007, 06:12 AM

Not to speak for Mark, but I think (it was for me anyway) that generally safe does not mean always safe, and the potential downside -- a $10-15k rebuild -- was not worth the extra performance.

All I did to my SE was an S4s chip and better exhaust. "Everyone" believes those cars can handle more boost and I had buddy who did that. His car was amazingly fast -- I think some of you V8 guys would be surprised by what a 4 cylinder Esprit, at a couple hundred lbs lighter can do - and reliable. I could have done that, but didn't, because I was driving my Esprit 3-4 times a week and frankly felt it was fast enough. Didn't need the risk of the added power.

Based on what Mark says, it seems that you can put 12 lbs on these cars with SOME confidence, but you just never know. Running more boost is always a risk at some level.

Feffman · 06-22-2007, 08:06 AM

Quote:

Originally Posted by JeffYoung

Not to speak for Mark, but I think (it was for me anyway) that generally safe does not mean always safe, and the potential downside -- a $10-15k rebuild -- was not worth the extra performance.

All I did to my SE was an S4s chip and better exhaust. "Everyone" believes those cars can handle more boost and I had buddy who did that. His car was amazingly fast -- I think some of you V8 guys would be surprised by what a 4 cylinder Esprit, at a couple hundred lbs lighter can do - and reliable. I could have done that, but didn't, because I was driving my Esprit 3-4 times a week and frankly felt it was fast enough. Didn't need the risk of the added power.

Based on what Mark says, it seems that you can put 12 lbs on these cars with SOME confidence, but you just never know. Running more boost is always a risk at some level.

Couldn't have explained it better myself!

Feff

06-21-2007, 09:54 AM	#43 (permalink)
lotuson74 Registered User Join Date: Aug 2005 Posts: 567	Pocono sounds like it's the event for me - Thanks guys!!! Even better, my new house is only 15 minuites from there I will sign up tomarrow __________________ Kirk Will this do??? Artic silver Elise, Ohlins, Monolites, Q.S. header Arqray Ti. & more 99 Sport 190 Elise 02 Mini Cooper S 03 Dinan BMW S-3 Supercharged X-5 4.6is 06 F-250 Diesel, 11 inch lift, 1000lb ft. hauler 04 Radical SR-4 Racecar 97 Lotus Esprit V-8 TT 04 Lotus Esprit V-8 TT 90 Nissan 300 zx TT showcar with 680 r.w.h.p.!! 02 BMW 330i (needed something practical!) 06 BMW M5 with Schnitzer & Dinan mods. (3) Racebikes built by Richard of Attack Racing Last edited by lotuson74 : 06-21-2007 at 10:21 AM.

06-21-2007, 10:19 AM	#44 (permalink)
lotuson74 Registered User Join Date: Aug 2005 Posts: 567	By the way... I NEVER said 26psi is "safe" I said: that I have done it on 4 Esprits without any failures when done in the specific manner that I do it. But I do believe 14 to 18 is safe with 109 unleaded race fuel (based solely on my personal experiances) I am also aware about the half shafts being a potential weak link along with the transmission BUT... I have had no problems! and I drive them all very hard. Even doing one full dead stop drag race with my 04 in which a G-Tech was in the car. At that time I was running 26psi and had on stickier rubber, the car did 0-60 in 3.3, Quarter mile in 10.8 @ 148mph! I do think I got lucky not to have broke something (that's why I have not done it again) I also run the car hard on roadcoarses at 15-16psi with no problems Not on pump gas - You WILL blow it up on pump gas! If you fear the driveline is weak - Use 155x75x14 four-ply tires on smaller wheels with an "under fender oil drip" as this will help preserve the driveline __________________ Kirk Will this do??? Artic silver Elise, Ohlins, Monolites, Q.S. header Arqray Ti. & more 99 Sport 190 Elise 02 Mini Cooper S 03 Dinan BMW S-3 Supercharged X-5 4.6is 06 F-250 Diesel, 11 inch lift, 1000lb ft. hauler 04 Radical SR-4 Racecar 97 Lotus Esprit V-8 TT 04 Lotus Esprit V-8 TT 90 Nissan 300 zx TT showcar with 680 r.w.h.p.!! 02 BMW 330i (needed something practical!) 06 BMW M5 with Schnitzer & Dinan mods. (3) Racebikes built by Richard of Attack Racing

06-21-2007, 01:03 PM	#48 (permalink)
mikelr <[^,^]> Join Date: Mar 2006 Location: Newburgh, New York Posts: 650	The old VDO speedos in the SE-S4s were mechanical and prone to being out of calibration. The newer speedos in post S4s were electronic. __________________ 00' S1 Exige (7.14lbs/hp) 94' S4 Esprit 07' Ram Quad cab 3500 hauler

06-21-2007, 08:26 PM	#54 (permalink)
lotuson74 Registered User Join Date: Aug 2005 Posts: 567	What really limits the Esprit's top end is - whare the rev. limiter stops you. It should at least go to 7400rpm. which is only about 180 - 185mph. But... I have had mine stop me cold at 7000 rpm. one time and it let me hit 7600 another time (195mph.) and it was still going, but traffic interviened Having driven your car stallion, I can tell you - it has ample power to hit 7400rpm. in 5th. But you will need a looonnnnnngggggggggggg streight to do it __________________ Kirk Will this do??? Artic silver Elise, Ohlins, Monolites, Q.S. header Arqray Ti. & more 99 Sport 190 Elise 02 Mini Cooper S 03 Dinan BMW S-3 Supercharged X-5 4.6is 06 F-250 Diesel, 11 inch lift, 1000lb ft. hauler 04 Radical SR-4 Racecar 97 Lotus Esprit V-8 TT 04 Lotus Esprit V-8 TT 90 Nissan 300 zx TT showcar with 680 r.w.h.p.!! 02 BMW 330i (needed something practical!) 06 BMW M5 with Schnitzer & Dinan mods. (3) Racebikes built by Richard of Attack Racing

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06-21-2007, 07:01 AM	#42 (permalink)
JeffYoung Registered User Join Date: Feb 2006 Posts: 837	Mark, how much boost does Johan's ECU run? Does it temporarily spike at 14+ lbs under initial hard acceleration like the 4 pot ECUs? Or does it limit boost to 12 lbs (less than 1 bar, right?)?

06-21-2007, 12:42 PM	#47 (permalink)
JeffYoung Registered User Join Date: Feb 2006 Posts: 837	Don't know about the V8s, but the speedo on my SE was rather optimistic. My SE speedometer would report about 10 mph over the Traqmate datalogger at "speed" (say indicate 145 when really at 135) on track. What was the "book" top on the V8? 178 or so? It does take a significant bump in horses to get another 12 mph at that speed.

06-21-2007, 02:55 PM	#49 (permalink)
StallionX BANNED Join Date: Mar 2007 Posts: 841	well if the car at 350hp can do 178, then I would assume the 450hp ones could do 190ish.. doesn't sound impossible.. with another 100hp..

06-21-2007, 03:04 PM	#50 (permalink)
JeffYoung Registered User Join Date: Feb 2006 Posts: 837	No, it is not that simple. Top speed is a function of wheel size, rear gear ratio, horsepower, coefficient of drag and frontal area. I forget how the equation works, but the gist of it is that as speed (and drag) increases, it requires more horsepower to bring out corresponding increases in top speed. Not saying a 450 hp V8 Esprit can't do 190, just saying it is more complicated that looking at a 350 hp V8 Esprit's top speed of 175 and extrapolating up.

06-21-2007, 03:54 PM	#51 (permalink)
StallionX BANNED Join Date: Mar 2007 Posts: 841	I know all about that Jeffery.. I am taking into account the likely scenario.. I remember reading how many HP was required to get x number of MPH high in your top speed, I believe 100hp more is enough to bring you another 15mph starting at 178..

06-21-2007, 04:07 PM	#52 (permalink)
JeffYoung Registered User Join Date: Feb 2006 Posts: 837	It's more than just hp and speed. You need to know cd and frontal area. 100 hp might get an Esprit 15 more mph, but it wouldn't get a bread van, for example.

06-21-2007, 06:10 PM	#53 (permalink)
StallionX BANNED Join Date: Mar 2007 Posts: 841	I totally understand.. you might need to remove the big v8 wing also to get a few more MPH in the esprit.. too much downforce..

06-21-2007, 08:36 PM	#55 (permalink)
StallionX BANNED Join Date: Mar 2007 Posts: 841	heheh yeah I've had mine up there.. maybe 180 or so I wasn't really looking at odometer at that speed.. it honestly gets up there pretty goddamn fast too..

06-22-2007, 05:22 AM	#58 (permalink)
StallionX BANNED Join Date: Mar 2007 Posts: 841	I thought you just said 12psi was safe? how would that result in a blown engine?

06-22-2007, 06:12 AM	#59 (permalink)
JeffYoung Registered User Join Date: Feb 2006 Posts: 837	Not to speak for Mark, but I think (it was for me anyway) that generally safe does not mean always safe, and the potential downside -- a $10-15k rebuild -- was not worth the extra performance. All I did to my SE was an S4s chip and better exhaust. "Everyone" believes those cars can handle more boost and I had buddy who did that. His car was amazingly fast -- I think some of you V8 guys would be surprised by what a 4 cylinder Esprit, at a couple hundred lbs lighter can do - and reliable. I could have done that, but didn't, because I was driving my Esprit 3-4 times a week and frankly felt it was fast enough. Didn't need the risk of the added power. Based on what Mark says, it seems that you can put 12 lbs on these cars with SOME confidence, but you just never know. Running more boost is always a risk at some level.

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