Diary - 427TT install
Discussion
Lag is not a thing of the past...
tractor pullers and big diesels use multiple turbos in series, to generate silly boost pressures ( 100psi anyone ? lol )
And they are laggy as hell at that !!! But once they start to go, they gooo
And two turbos by the rear wheels has been done before. STS offer both single and twin turbo kits.
But in general, for a big engine like a 5.7, or indeed a 7.0, lag isnt a massive concern. Fuel economy should stay good, as long as you havent went for a silly low CR
tractor pullers and big diesels use multiple turbos in series, to generate silly boost pressures ( 100psi anyone ? lol )
And they are laggy as hell at that !!! But once they start to go, they gooo
And two turbos by the rear wheels has been done before. STS offer both single and twin turbo kits.
But in general, for a big engine like a 5.7, or indeed a 7.0, lag isnt a massive concern. Fuel economy should stay good, as long as you havent went for a silly low CR
stevieturbo said:
Lag is not a thing of the past...
tractor pullers and big diesels use multiple turbos in series, to generate silly boost pressures ( 100psi anyone ? lol )
And they are laggy as hell at that !!! But once they start to go, they gooo
And two turbos by the rear wheels has been done before. STS offer both single and twin turbo kits.
But in general, for a big engine like a 5.7, or indeed a 7.0, lag isnt a massive concern. Fuel economy should stay good, as long as you havent went for a silly low CR
you dont neeed to use a twin stage system for 100 psitractor pullers and big diesels use multiple turbos in series, to generate silly boost pressures ( 100psi anyone ? lol )
And they are laggy as hell at that !!! But once they start to go, they gooo
And two turbos by the rear wheels has been done before. STS offer both single and twin turbo kits.
But in general, for a big engine like a 5.7, or indeed a 7.0, lag isnt a massive concern. Fuel economy should stay good, as long as you havent went for a silly low CR
with less pressure smaller turbos can be used that spin up quicker
modern turbo design has really decreased lag with twin scroll and other features ie sequential turbos
and of course ALS
lag is only now really a problem when the turbos are too big for the application
plus i think this car will be used in a straight line mainly
If its straight line stuff then why not use nitrous to overcome lag? Read that in the early days of turbo's lag was a major concern. Some guys found a healthy dose of gas gave the instant hit till the turbo(s) woke up! Tho where you'd put the bottle on a 56 plate? Boot's not big enough as it is!
tzh said:
If its straight line stuff then why not use nitrous to overcome lag? Read that in the early days of turbo's lag was a major concern. Some guys found a healthy dose of gas gave the instant hit till the turbo(s) woke up! Tho where you'd put the bottle on a 56 plate? Boot's not big enough as it is!
bottle between wifeys legs
ringram said:
What boost are you aiming at? 14psi?
With standard 427's running 600bhp no problem a 14psi well setup one should do that not a problem. In fact 8psi might be enough, Im sure Mike has crunched the numbers.
Expecting to run somewhere up to 18psi for four figures based on calcs done, but have to wait and seeWith standard 427's running 600bhp no problem a 14psi well setup one should do that not a problem. In fact 8psi might be enough, Im sure Mike has crunched the numbers.
Embedder said:
Here is some fun for you guys.
I like it, sounds awesomecrisisjez said:
Just a question Harry, but how long do you usually keep your cars? 
Prefer not to get rid of them, they usually go when I either run out of space or wear them out 
SplatSpeed said:
plus i think this car will be used in a straight line mainly
Plan to use it in corners as well, but doubt that will be with foot on throttle past a few thousand rpm...On the subject of lag, for this install it is our friend. We specced larger turbos to introduce lag such that there is a driveable rev range (up to 3000-3500rpm) before lift off. It is intended to be a road car after all
stevieturbo said:
Speccing "laggy" turbos wiould only make the transition from off boost, to on boost more dramatic.
The correct way for smooth power delivery, would be for a fast spooling turbo, and to map boost vs rpm or TPS, to give a progressive power delivery.
But "dramatic" is sooo much fun, oh the rush!The correct way for smooth power delivery, would be for a fast spooling turbo, and to map boost vs rpm or TPS, to give a progressive power delivery.
For smoothness the intention is to moderate the transition via boost level management.
Harryoz said:
stevieturbo said:
Speccing "laggy" turbos wiould only make the transition from off boost, to on boost more dramatic.
The correct way for smooth power delivery, would be for a fast spooling turbo, and to map boost vs rpm or TPS, to give a progressive power delivery.
The correct way for smooth power delivery, would be for a fast spooling turbo, and to map boost vs rpm or TPS, to give a progressive power delivery.
But "dramatic" is sooo much fun, oh the rush!
For smoothness the intention is to moderate the transition via boost level management.
Does that mean not pressing so hard with your right foot?
crisisjez said:
Harryoz said:
stevieturbo said:
Speccing "laggy" turbos wiould only make the transition from off boost, to on boost more dramatic.
The correct way for smooth power delivery, would be for a fast spooling turbo, and to map boost vs rpm or TPS, to give a progressive power delivery.
But "dramatic" is sooo much fun, oh the rush!The correct way for smooth power delivery, would be for a fast spooling turbo, and to map boost vs rpm or TPS, to give a progressive power delivery.
For smoothness the intention is to moderate the transition via boost level management.
stevieturbo said:
You will find, that it is a bad choice. Trying to control turbo power like that under foot, is near on impossible
When the boost starts to climb, 40% throttle may as well be 100% throttle
Anyway....Santa Pod here I come then off to York for TOTB
When the boost starts to climb, 40% throttle may as well be 100% throttle
Anyway....Santa Pod here I come
then off to York for TOTBYou at the Pod on Sun?
Didnt realise you were there Richard ?
I was racing/testing on friday, and just lurking about on Saturday.
Times werent improving much, so just relaxed on saturday. No sense trying to destroy another before TOTB on sunday.
Although this temporary engine seems to be hanging together rightly !!
Could only manage 10.49 @ 138mph...so its defo way down on power over last engine.
Still...it did manage 190.7mph in the standing mile on Sunday. So it isnt all bad. When I get my power back....200 might be possible !!! ( in a mile
)
I was racing/testing on friday, and just lurking about on Saturday.
Times werent improving much, so just relaxed on saturday. No sense trying to destroy another before TOTB on sunday.
Although this temporary engine seems to be hanging together rightly !!
Could only manage 10.49 @ 138mph...so its defo way down on power over last engine.
Still...it did manage 190.7mph in the standing mile on Sunday. So it isnt all bad. When I get my power back....200 might be possible !!! ( in a mile
)
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