GTS tuning options
10-28-2013, 06:09 PM
#1
Racer
Thread Starter
GTS tuning options
i know this has been asked before, just interested if peoples thought are still the same? i race a old gts in the uk, after winning most races i went in during 2011 and 12 im now playing catch up and never won in the gts this year after the opposition got fed up of coming 2nd and upped there game.
the engine is stock except for a x pipe and equal length headers, im putting 18 inch wheels on as i couldnt get wider than a 255 17 inch tyre in the ones i ran since 2005, so struggled to lay down anymore horsepower even with new tyres
im thinking a bit more power and grip for next season.
what are the best bang for buck mods and rough costs for cams, inlet ie itbs or anything else?
thanks in advance mark
the engine is stock except for a x pipe and equal length headers, im putting 18 inch wheels on as i couldnt get wider than a 255 17 inch tyre in the ones i ran since 2005, so struggled to lay down anymore horsepower even with new tyres
im thinking a bit more power and grip for next season.
what are the best bang for buck mods and rough costs for cams, inlet ie itbs or anything else?
thanks in advance mark
10-28-2013, 06:19 PM
#3
Racer
Thread Starter
the body must look stock, which it does. no sequential boxes. must use road tyres like toyo 888s etc. i run mich pilot cups which on this big old bus last 40 minutes flat out no probs.
can do any brake/suspension/engine mods.
ive got some spare 997 cup brakes off my cayman racer so might put them on.
i race a couple of turbocharged cars, never thought of a turbo 928. tell me more..
can do any brake/suspension/engine mods.
ive got some spare 997 cup brakes off my cayman racer so might put them on.
i race a couple of turbocharged cars, never thought of a turbo 928. tell me more..
10-28-2013, 06:24 PM
#4
Nordschleife Master
Here's one option:
https://rennlist.com/forums/928-foru...e-streets.html
This is an achievable dyno chart for otherwise stock '87 5.0 S4 motor, except turbos:
Cooling and oiling have to be in order, of course, before running that engine on a track.
10-28-2013, 06:54 PM
#6
Racer
Thread Starter
to be honest i like turbos more. i always see it as free power the way they are driven. plus the weight is lower down and slightly further back with the turbo set up. what sort of costs are involved with a turbo conversion? i wouldnt need that much power to get back to the top of the podium. another 100hp i reckon, so a low boost set up would be ok.
i know what you mean about keeping them cool, or at a certain temp! ive got a cayman with a 997 tt engine. keeping the inlet temps down is a battle to have consistant hp thoughout a race
thanks for your help so far
regards mark
i know what you mean about keeping them cool, or at a certain temp! ive got a cayman with a 997 tt engine. keeping the inlet temps down is a battle to have consistant hp thoughout a race
thanks for your help so far
regards mark
10-28-2013, 07:36 PM
#7
Race Car
Cheapest 928 turbo option is probably the mid/rear mount turbo. You can get a relatively easy 450rwhp out of one. Do a search on those, there are quite a few posts on this subject.
Dan
'91 928GT S/C
475hp/460lb.ft
Dan
'91 928GT S/C
475hp/460lb.ft
Trending Topics
10-28-2013, 10:07 PM
#10
Former Vendor
I do not think that a supercharged or turbocharged vehicle will survive for very long, under racing conditions. Most of the supercharged or turbocharged engines, out the in the 928 world, have never been run long or hard enough to reach thermal endpoint.
If you want reliable power you need a stroker.
If you want reliable power you need a stroker.
10-28-2013, 10:35 PM
#11
Nordschleife Master
I would disagree with Greg. With forced induction, you can get a more reliable car with more power spending less cash, than if you try to increase displacement. Give me a budget, and the forced induction car beats the stroker both in power and reliability. Give me power and reliability goals, and forced induction gets you there with way less dollars than a stroker. In my opinion, there's no question about that. As long as the rules don't give a displacement penalty for forced induction, forced induction dominates in every respect. Of course, you can screw up any build, but holding the builders skill constant, that's how it's going to play out.
Well, that's at least what I think. Can I get a witness?
George Suennen runs a supercharged ORR car with a near-stock bottom end built by Jim Morton. That car is run at full throttle for long stints.
Does anyone run any of the many Murf kits on track?
"Justaguy" runs a whipple-charged 928 in Canada.
Etc.
Now, if you want an interesting hp/usd argument, then let's unbury the ancient hachet and let's restart the turbo vs. supercharger wars! ;-)
Well, that's at least what I think. Can I get a witness?
George Suennen runs a supercharged ORR car with a near-stock bottom end built by Jim Morton. That car is run at full throttle for long stints.
Does anyone run any of the many Murf kits on track?
"Justaguy" runs a whipple-charged 928 in Canada.
Etc.
Now, if you want an interesting hp/usd argument, then let's unbury the ancient hachet and let's restart the turbo vs. supercharger wars! ;-)
10-29-2013, 01:29 AM
#12
Three Wheelin'
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Guys... please put these "silly" engine / power arguments away. IMHO, these debates are a complete waste of time unless the debate locks down a lot more parameters then simply debating "best". There are SO MANY elements / results that might be prioritized as "best", that "best" is in the eye of the beholder and what they perceive the engine needs to do. Lot's of good 928 engines have been built over the years. Many engines have survived well, others not as well...
As the person who "oversaw" George Suennen's engine assembly (not a rebuild), there was nothing "magic" done with George's engine than a LOT of attention paid to details. After several ORR passes now made with the engine, from what I hear about the engine, it's now pretty much dead, needing another build (I have not been involved since the assembly). Given this now known, many on this board would consider the engine a complete failure, especially if you knew how few miles are actually on the engine. Others may still think it's a success, especially if you knew that the engine was based on a "pile" of used parts. Frankly, I was surprised it held together as long as it did... Regardless of all the opinion(s), it only really matter what George thinks of it and how it helped his ORR program meet the goal... 200MPH.
Above comment retracted.., corrected by Bill Ball in a later post. For all information about George Suennen's engine, please disregard anything I have said and contact Bill or George... thanks...
After basically going broke and punting my 928 program, I applaud anyone who sticks with the 928. In my opinion, as long as someone has fun with their program and your family is OK with it, ENJOY the fun !
This said, do consider that there IS more than one way to make power (even with a 928) and it's really a question of what power band you want to play with and for how long you expect the engine to last.. that is without either needing internal maintenance or allowing the engine to be turned into scrap.
Last edited by Jim Morton; 10-30-2013 at 12:51 PM.
10-29-2013, 02:12 AM
#13
Rennlist Member
Guys... please put these "silly" engine / power arguments away. IMHO, these debates are a complete waste of time unless the debate locks down a lot more parameters then simply debating "best". There are SO MANY elements / results that might be prioritized as "best", that "best" is in the eye of the beholder and what they perceive the engine needs to do. Lot's of good 928 engines have been built over the years. Many engines have survived well, others not as well...
As the person who "oversaw" George Suennen's engine assembly (not a rebuild), there was nothing "magic" done with George's engine than a LOT of attention paid to details. After several ORR passes now made with the engine, from what I hear about the engine, it's now pretty much dead, needing another build (I have not been involved since the assembly). Given this now known, many on this board would consider the engine a complete failure, especially if you knew how few miles are actually on the engine. Others may still think it's a success, especially if you knew that the engine was based on a "pile" of used parts. Frankly, I was surprised it held together as long as it did... Regardless of all the opinion(s), it only really matter what George thinks of it and how it helped his ORR program meet the goal... 200MPH.
After basically going broke and punting my 928 program, I applaud anyone who sticks with the 928. In my opinion, as long as someone has fun with their program and your family is OK with it, ENJOY the fun !
This said, do consider that there IS more than one way to make power (even with a 928) and it's really a question of what power band you want to play with and for how long you expect the engine to last.. that is without either needing internal maintenance or allowing the engine to be turned into scrap.
10-29-2013, 06:21 AM
#14
Drifting
Did Adrian build a stroker? I know ITBs can be converted for use from an m5, this would be my next upgrade before considering either a stroker or forced induction. How many ponies are you making now?
10-29-2013, 06:51 AM
#15
Rennlist Member
The supercharger modification for the GTS was very popular in the 90's in Germany. But none (or very few) cars are still around and have survived. Most of them died on the Autobahn....
Friend of mine nearby Munich has a supercharged GTS. That thing is a monster (when it runs) and we gave it the nickname Godzilla. But every time when he writes me a PM there are problems with the engine.
Latest issue: blown head gasket...
At least he owns a German specification 5 speed 928 S. Which he enjoys more
I would be very carefull with a good GTS engine. But these are just my 50 Cents...
Friend of mine nearby Munich has a supercharged GTS. That thing is a monster (when it runs) and we gave it the nickname Godzilla. But every time when he writes me a PM there are problems with the engine.
Latest issue: blown head gasket...
At least he owns a German specification 5 speed 928 S. Which he enjoys more
I would be very carefull with a good GTS engine. But these are just my 50 Cents...