prepped 308 vs ??

Not that I have any first hand experience but I would conjecture that setup would be slightly quicker than a 993 or NSX, due to superior power/weight ratio and better suspension/brake setups. In terms of F-cars perhaps a 348, maybe a tad quicker. Probably much closer to a 348 than a 355. Would be curious to see how this setup would hold up against some of the older V12 cars though.

 

john

i dont think even with the favorable power to weight of your upgraded car u can do laptimes near a nsx, 993 or even a 348.

i sure do hear a lot of performance projections on f-chat based on power-to-wieght. biggest thing imo is the very high CG of the 308 drivetrain and the stock brakes. not much you can do about the CG unfortunately. the 348 drivetrain is located nearly 5 inches lower than the 308 due to the "upsidedown" imput shaft and the unit is much lighter as i recall.

if you r fixed on a really quick time trials car dont use a 308 to begin with. having said that i applaud and respect every signal 308 owner of trying to improve their cars and use them at the tracks as often as they can. although dated it is still a fabulous involving car to drive especially at that track but dont expect to run down any NSX or 993 unless you find an incompetent driver behind the wheel.

just for reference ive been to a few formula one races in the 90's were the porsche cup guys raced on the same track on the same day as the ferrari challenge guys. 993 vs 348 and later 996 vs 355 series. the porsches guys laptimes where in another hemisphere. although not in the same race you can compare laptimes. the speed difference wasnt even close being seconds faster. of course alot of the porsche cup drivers were hired guns and the f-car drivers were gentleman racers which makes a big difference.

respectfully

hf

 

Once again the PM system does not seem to work for me.. .. Thus this reply about cam timing to a PM sent this week


Do a search for " P6 cam timing" and then go to the last thread that I started when I was putting my engine together. As I recall I set the cams up as follows

Intake opens 42 BTDC closes 71 ABDC
Exhaust opens 67 BBDC closes 40 ATDC

These settings resulted in the cam timing marks on the P6 cams exactly matching the marks on the head. So, at least I know that I ended up with "factory timing" Let me know if you need anything else.

 

its just not the power to weight but where the central weight of the mass is located. i bought this up on another tread comparing a mondial 3.2 and a mondial T on track use. a fellow poster had a good insight and experience on the track on both drivetrain orientations... his comments are revealing.

after 25 years of hanging around the tracks you get a feel of what the cars are quick and what types arent. many times its not the power to weight that determines that. small seemingly insignificant attributes like brake feel, steering accuracy, shifting speed, confidence in the chassis can add or reduce 10ths of secs at every corner. over the length of the track these franctions of the second can add up. as far as im concern there still hasnt been a documented lap time of a street prep 308 in the usa that can match with a relatively stock scca 140hp spec miata. ive asked this question before on F-chat and no one has came forward as of yet.

i've never tracked a nsx so i cant say from personal experience of its handling vices. ive also hear the nsx can be tricky to drive at the limit like most dated mid engine cars. the last time i ran laguna seca, one street prep NSX did a devastating time in low 1:40s. find me a 308 that can come within 15 secs of that please. im sure more than a few 308s have been timed there but no one really post their times. believe me i'd be elated to hear of some respectable street 308 lap times anywhere.

comparing ferrari challenge vs the porsche cars was to help illustrate power to weight debate. they are both street car based with minor engine modifications. case in point the F-cars always had a significant power to weight advantage over the P-cars. still the porsche was much quicker in all the races. P-to-W is important but other factors still plays a significant roll. just look at what the type of cars the GT-R is pitted against lately.

yes the newer 430 are quicker but thats a entirely different family of cars compared to a 348/355. one would hard press to build any street car to run with a 430 challenge car. maybe a 308 michelotto GR5 biturbo might have a chance?

looking forward to your 308 build... im sure its going to be a big improvement over the stock configuration ... please keep us posted

cheers

hf

 

what kind of gearing?

That's gonna make a difference

 

I have had all 3 cars and currently the 308 and 993. Can't comment on the handling upgrades, but even if my 308 had the same power as the NSX or 993, I would not have the overall confidence in the car at speed. I just don't see it feeling as nimble or confidence inspiring as the other 2 cars. But once again, it is older technology and design. However, none of this means that it is not more fun to drive than the other 2.

 

I don't know John, but if I had to choose between a bone-stock 993 and a prep'd 308 as you describe, I'll take the 993 any day. The 993 is such a great handling car with completely modern suspension geometry. The engine is also pretty torquey and torque is what you feel coming out of a corner, not hp. And, the 993 brakes are in a whole different class than 308 even with tweaks. With equivalent drivers I suspect you'd see a second or two difference per lap with the 993 out ahead..... Just my $.02.

Like I've said before, taking the 308 to the track seems sort of like taking your grampa out paintballing with your college drinking buddies.

 

Once you have some track experience it will take one helluva driver to walk away from you in most cars if you have a properly setup 308. I ran with a 360 Stradale recently ... I did have slicks but the guy finally out braked himself 'cause he would leave me a bit on the straight but I would always catch him on the twisties. It's not the Fontana video I posted here which was just a 360 spider I was slapping around.

Here's when you know you have your 308 sorted ... the oil baffle upgrade is f'g useless. I run my car way overfull even with street tires and she still starves ... with slicks I'm watching the oil pressure gauge with one eye and never powering down like I can with my P car 'cause of oil pressure problems.

So ... if someone tells you they think know what a 308 is capable of, first question should be "wet sump or dry sump car?". Then don't get me started on carb starvation . How fast do you really want to go? .

cheers

 

Just another thought ... guys are always noting lap times with a certain car with some very experienced driver at the wheel. If you got to a typical track day with the cross section of typical "drivers" some of the lap times of certain cars will not be so impressive.

If you put a good driver behind the wheel of a 308 the first thing he'll do is a blow it up on a right hander (assuming the driver wasn't warned to watch the oil pressure ) ... this is also assuming the guy who set the car up threw away the factory manual. I remember reading some guy's comments on how the car pushed without even questioning alignment ... that is car setup 101 and I rarely see it talked about here.

Just sharing my thoughts since you're asking about going fast .

cheers

 

Agree and disagree. Power to weight ratio is not the only indicator of lap times, and all the little things do add up and make a difference. I do feel that you are giving some of the other cars too much credence in these factors though. The 308 is definitely going to be the slowest shifting of all the vehicles mentioned, but I would say that it is a wash with the NSX in terms of weight dynamics (the NSX is transverse mid mounted setup that sits atop the transmission as well) and superior than the 993 (the 993 might have a lower center of gravity, but lets not forget where the engine sits). One of the most important factors not taken into consideration with P/W ratios is drag. Of these three cars the 308 has the superior drag figures (http://74.125.93.132/search?q=cache:bOZjLgxjm5oJ:en.wikipedia.org/wiki/Automotive_aerodynamics+ferrari+308+drag+coefficient&cd=4&hl=en&ct=clnk&gl=us).

Now even if all these factors were all weighted in the favor of one of these particular vehicles I just don't see it making anywhere close to a 15 second lap time difference. That is unless we are talking about a 500hp, 3500lb car versus a 200hp, 1500lb car on a long lap with some really long straights. Also a Nissan GTR is the worst candidate you could probably use to exemplify the triumph of all these attributes over P/W ratios. Performance (and dyno) tests of the GTR have varied widely with rumblings that the early press cars were 'ringers' . (http://www.motortrend.com/roadtests/coupes/112_0803_2009_nissan_gt_r_dyno_test/index.html, http://74.125.93.132/search?q=cache:MB7QYhR6DR0J:www.caranddriver.com/features/08q4/what_is_the_gt-r_s_real_horsepower_-column+nissan+gtr+early+car+dyno&cd=5&hl=en&ct=clnk&gl=us).

 

Luckydynes I'm interested to here about your chassis setup ? Possibly you could start another thread on this ?

 

+1!

 

This is a fun thread!!! I like it!

Learning a lot by observing all the comments.


PDG

 

+2

any a couple of lap times on big willow, button and LS please....

 

This about sums up what I'm having. Except for the brakes. I'll start on those in a few weeks.

It's indeed comparable to a Porsche 993, and beats a 964. The 964 owner REALLY tried (and finally moved over at 140 mph to let me pass, with a very grumpy face)

Hans
(Euro 1974 308GT4, 257 hp @ crank, 16" wheels, 300/300 QA-1's, upgraded rear roll bar, poly bushings, BSM ignition, X-OST muffler)

 

within 15 secs of 1:40 @ LS... come on guys, your saying all the 308 driven there never been timed?

lets see how quick they really are. sub 2:00 at LS is a respectable time for a 35 year old street car. there should at least be a couple?

so what you reckon the CdA of the 308? i dont think its as slippery as NSX or 993... never mind the lift. i had aero numbers of all these cars somewhere.

the nsx motor doesn't set on top of the gearbox btw... the gearbox imput shaft is near the same height of the diff flanges.

 

My actual lap times at Big Willow suck in the 308 either because of weather or car issues on a particular day. I started a thread a year or so ago where I wanted to run some numbers on theoretical laps but no one jumped in or followed up on it. I think it's a pretty fundamental calculation ... it's not going to be perfect but I think it would be a very repsectable time and be within a few seconds of what could actually be put down.

Modified (not full race) Boxsters and 944 spec cars run 1:35's at Big Willow and I usually beat or run the same times at autocrosses and DE's with the fastest in these run groups for comparison ... they might not be the greatest drivers either but neither am I. When I went to Willow with my old suspension based on my data I figured I could run a 1:40 once I had the balls to take 8 and 9 like a man ... but I've become a bit more focused on developing the machinery and leaving the wheel work on +140 mph sweepers to a pro. I also think I'd want a cage pushing those speeds at Willow which I would justify if I thought we could break under 1:30, which I think is possible with a gutted version and the right driver.

cheers